Nicholas Fluhart

December 2, 2010

Project: Yamaha 350 Moto-4

Filed under: Project: Moto-4 — nfluhart @ 6:16 pm

I completed an interesting project a while back. It is a 1989 Yamaha 350 Moto-4. I love old machines! These bikes were the predecessor to the 2WD version of the Big Bear. This was a very heavy-duty machine, and as such there were some very interesting industrial variations of it that were groundbreaking in the industry. One of these was the Terrapro which had, to my knowledge, the only Power Take Off (PTO) available on a four wheeler. It had a variety of very functional attachments available from Yamaha, such as a rough cut mower, finish mower, tiller, etc. The other innovative spin-off was the Pro Hauler, which utilized what is considered the first ATV cargo bed. In contrast, the 350 Moto-4, while industrial at heart with it’s Hi/Lo 10-Speed transmission, is more of a general purpose utility ATV.

I stumbled into it almost unintentionally. I purchased a group of ATV’s in south east Arkansas and this one was in the lot. I essentially got it for free. It looked fairly junky and I didn’t have any specific interest in it at the time, so it was unloaded and hauled around back where it stayed for a few months. Here’s a video clip of me unloading it at my shop:

When I bought this quad, I never intended to do anything but scrap it. My initial thought was to either sell a few easy parts, such as the carb, CDI, etc., and scrap the rest, or perhaps sell it whole as-is for parts or a project bike. However, upon closer inspection, I noticed a few things that grabbed my attention: The bike still had the factory original tires on it, which were in good shape. All the wheel bearings and seals were in good condition. Although the cosmetic condition was very weathered, the bike was remarkably untouched and noticeably sound overall.

So what does all this mean? It means that the bike probably didn’t have any real hours on it, and thus the mechanical condition was likely in decent shape requiring only minor restoration. My theory was that the bike was adult owned and ridden for most of its life and perhaps was later passed down to a kid who promptly broke it and left it out in the weather for a couple of years. With this in mind, I decided to see what it might take to get it running. If it could be repaired easily, I could fix it up and it would be worth around $1200 to $1500. So I pulled it up in the shop…

As I looked it over, I made a few notes. The one thing I knew it needed immediately was a carburetor and a hot battery. I already knew the chassis was in good shape, so if the engine ran good, all it would need was a quick cosmetic restoration. The good thing about being in the parts business is that I usually have a few spare parts laying around. While I didn’t have a carburetor for a 350 Moto-4, I did have one for a 350 Warrior so I decided to make it work. I cleaned it thoroughly and found an intake boot. I then installed the assembly using the Warrior throttle cable (P.S. The aftermarket intake boot is ridiculously fragile. They split easily. I went through two of them on this project).

 

 

Warrior Carb on the Moto-4 Intake Boot

 

 

Installed

Well, good news and bad news. The good news is that the engine ran. The bad news is that it was a total travesty. The jets in the Warrior carb were too rich for a stock setup, so it ran poorly and smoked. Also, the cam chain in the engine was rattling and the starter clutch was going out. Decision time: Do I scrap the project or order some parts? For me to make any money on this thing, I need my total investment to be $500 or less. So I needed to guesstimate my total parts bill if I fixed this thing from one end to the other in order to sell it for a good price. It’s always a bit of a gamble, but I ran some loose numbers and given my access to used parts and my discounts on new parts, my figures indicated I should be OK. Theoretically.

So I went for it. I ordered a carburetor kit for around $20 and a D.I.D. cam chain for $25. For the starter clutch, I went used. I got on eBay and won an auction for a Warrior flywheel, starter clutch, stator assembly, and stator case, all for $55 (the Warrior and Moto-4 starter clutches are interchangeable). I only needed the starter clutch, so I kept that and resold the bare flywheel for $35, and the stator w/case for $85. So that puts my total parts bill thus far at -$20. I’ve already made 20 bucks and I haven’t even done anything! I love eBay! Moving on…

So I pulled the carb back out and installed the kit:

 

 

Using the stock jets seemed to fix my rich burn problem. The engine ran pretty good, albeit noisily. I jumped on it to test drive it and check the clutch and transmission. It actually drove pretty good and had a lot of power, but unfortunately it revealed a few other problems. The engine smoke didn’t clear up and the centrifugal clutch wouldn’t disengage. This project, like most, was rapidly snowballing.

Oh well…in for a penny, in for a pound. I decided to disassemble the engine and assess the damage. If my hunch was right, all it would need is a set of rings, and since I already had to partially disassemble the engine to replace the cam chain and starter clutch, it would only take a few more steps to install a set of piston rings.

First I addressed the centrifugal clutch issue. It turns out that the shoe springs had fallen off somehow and were digested by the transmission. Hmm….I’ve never quite seen that happen before, but there’s a first time for everything. After ordering and receiving the wrong springs twice, I decided to replace the entire centrifugal clutch assembly with one I had on the shelf which was out of a 1995 Kodiak 400. Success!

Then I began the main teardown. I removed the head, cylinder, and then the stator and case and of course the flywheel/starter clutch assembly (this requires a special tool) and I was then able to remove the cam chain.

 

 

Cylinder Head Removed

 

 

Cylinder Removed

Once removed, I saw that the piston rings were worn. I made note of the size and ordered a set for around $20. The cylinder was in decent shape for the most part, but there was a slight ring ridge at the top. Rather than risk breaking my new rings, I used a Zimmerman Ridge Reamer to remove the ring ridge. Some of you old-timers may know what that tool is. It’s a cutting tool invented by Herman W. Zimmerman in 1935 that’s designed to cut ring ridges much like a boring bar would. It worked perfectly. I then honed the cylinder and installed the new rings.

 

 

Reaming the Ring Ridge

 

 

Cylinder Installed

To install the new starter clutch sprag, I first had to remove it from the Warrior flywheel and install it on the Moto-4 flywheel. While many would mistakenly believe the two flywheels are interchangeable, they are not. If you look closely you will see the ignition pickup surface is longer on the Moto-4 and is located in a different position.

It is very difficult to get the bolts out of these because when the factory installed them, they took a punch and smacked the end of the bolt after it had threaded through. This was to swell the threads and prevent the bolt from becoming loose. Since they are Allen bolts, you can’t get much torque on them without rounding them off. So what do you do?

I took my angle grinder and gently ground off the swelled end portion of each punched bolt. I ground it down smooth with the surface as seen below.

 

 

Using the Grinder

 

 

Bolt end ground smooth.

I was then able to take my impact driver and remove the bolts manually.

 

 

Removing the bolts with an impact driver.

 

 

Once ground smooth, the bolt turns easily.

Then it was time to install everything. It worked out good. The engine started smoothly with the new starter clutch. It ran quiet with the new cam chain and did not smoke with the new rings. It also shifted perfectly with the new centrifugal clutch. So now I’ve got a good, running ATV with only about a $20 parts bill and lots upon lots of labor. Oh, and it still looks like trot-line weight. So now it’s on to cosmetics…

I pulled all the racks to straighten and paint them. The rear rack had a noticeable bend in the top bar, so I had to use my torch to heat it until the metal was glowing and soft. I then took my pry-bar and straightened it.

While I had the racks, seat, and gas tank removed, I went ahead and sent the seat to be recovered ($40) and I fixed a leak in the gas valve as seen below. It was also a good time to wet-sand the fenders to bring the color back to them. I then replaced the left rear mud flap with a New Old Stock (NOS) flap I had on the shelf. I also fixed the tail light and installed a new lens that I had on the shelf.

 

Repairing Gas Valve

The last little bit I had to do was fix the rear brakes. It utilizes a cable-operated mechanical disc brake. I had to replace the hand cable, but the foot cable was good. Fortunately, the pads and caliper were in good shape. All I really had to do was clean and properly adjust everything.

I pulled the right rear wheel off to assess the situation, then I disassembled the brake assembly:

 

 

I cleaned and painted everything. It worked like a new one.

 

 

After the cosmetics were cleaned, painted, polished, and whatever else needed, I began the most important part: installing my favorite accessories.

I generally utilize the same type of accessories on all of my utility ATV’s. Although I’m building this one to sell, I still may use it around the yard or as a backup until it sells, and I like to have all the features I’m used to. These include: auxiliary lighting (specifically on the rear), CB radio, and a good winch.

I started with the winch. This ATV already had a winch, but not much more. There was no auxiliary winch solenoid or wiring. The winch was an old-school 2,000 lbs Super Winch mounted to a thick steel plate on the front rack. It worked great but needed to be wired properly. First, I needed a solenoid. I had a good single-wire unit on the shelf, likely from a Polaris. I found a place to mount and ground it to the frame. Then I wired from the winch, where the main operation toggle was located, to the battery. I then wired a master On/Off switch so the solenoid would not engage and the winch could not be operated unless the main switch was in the “on” position. This is a safety feature that prevents the winch from accidentally engaging when not in use.

 

 

Winch Solenoid

 

 

Installed

Once the winch was taken care of, I proceeded to the other accessories:

 

Light and CB Radio

I installed the CB radio and antenna. The radio is a Cobra 19 Ultra III. It actually talks very well for a less expensive radio. The idea is to use a small, less expensive radio, not because I’m cheap, but because it will see rough service and potentially some weather, so if it breaks you do not want to be using a 29 LTD Classic. Next I installed the rear light and wired it to a toggle switch next to the master switch for the winch.

 

 

And that pretty much concludes this long ordeal of a project. I kept the quad for a few months, using it around the yard. It was a smooth riding machine with a very tight turning radius. I really enjoyed it. In fact, I would have liked to have kept it for a yard quad, but I’m limited on space so I had to make room for the next one. Here’s what it looks like now…

 

 

 

 

 

 

My total parts and supplies bill was very nominal, and after enjoying the quad for a few months, I sold it for $1300. Although the whole thing snowballed into much more than I had anticipated, it was a fun, profitable project. That’s all I can ask for. On to the next one!

About these ads

61 Comments »

  1. Boy did that thing look good in the end.

    Comment by Philip — December 5, 2010 @ 9:09 pm | Reply

  2. Thanks. That’s what makes it all worth it. Remember Steve had one similar to this when we were kids? His was a 225.

    Comment by nfluhart — December 6, 2010 @ 8:01 am | Reply

  3. I have a 1989 moto4 350 and I am thinking the CDI is out. I cant find one. What other model will cross over for this part?

    Comment by Rob — April 30, 2011 @ 2:46 pm | Reply

    • Unfortunately, CDI’s were exclusive for that year, meaning an ’89 model is the only one that will work. However, the 1989 Big Bear 350 4×4 uses the same part number according to Yamaha, so that at least gives you one more option in finding one. A new one, if still available, is $613.47 if you can believe it, so finding a used one will definitely be the way to go. Worst case scenario, you can go with a newer year model unit that is easier to find, but that would require changing out the stator, harness, and possibly other components.

      -Nicholas

      Comment by nfluhart — April 30, 2011 @ 3:11 pm | Reply

  4. Do u know what other clutch pack will fit a 95 yamaha Kodak centrifugal clutch

    Comment by joe — May 27, 2011 @ 8:15 am | Reply

    • I believe the 350 Big Bear 2WD and 4WD will work, as well as the 350 Wolverine and Moto-4. It’s also possible the 400 Big Bear would work, but I would confirm some part numbers and/or compare the parts before purchasing one.

      Comment by nfluhart — May 27, 2011 @ 4:12 pm | Reply

  5. i have a moto 4 350 that i think the centrifugal clutch is out of is there anything i can do instead of buying a 400 dollar part?? like is there anything i could switch over from a warrior?

    Comment by Tyler — August 23, 2011 @ 4:09 pm | Reply

    • The Moto-4 has two clutches, a centrifugal and a main clutch. The Warrior has only one, a main clutch, so it won’t be any help to you if you are sure that your problem is the centrifugal clutch. The early Moto-4 350′s through about 1989 used a centrifugal clutch with no outer retainer plate. I have a good one I would sell for $75. The shoes and drum are in great shape, comes with the one-way bearing sprag, but it is missing two shoe springs which can be purchased from Yamaha rather cheap. The later models had the outer retainer plate on the clutch pack, which was apparently added to prevent the shoe springs from coming off, and I have one of those also. It is ready to go for $120. Both types of clutches are interchangeable, so regardless which year model you have, either type will work. As I discuss in my post here, I used a clutch from a 400 Kodiak. The compatible clutches for the 350 Moto-4 are the Big Bear, 400 Kodiak, and possibly the Wolverine.

      Comment by nfluhart — August 24, 2011 @ 7:46 pm | Reply

  6. is there any number or email address i can contact you on bc i’ll buy that from you right now!!!

    Comment by Tyler — August 25, 2011 @ 11:22 am | Reply

    • I’ve sent you an email with my contact info…

      Comment by nfluhart — August 25, 2011 @ 7:12 pm | Reply

  7. Excellent job Nicolas! I’m an aircraft mechanic who also works on cars, lawn mowers,etc but I’ve done very little work on motorcycles and atv’s. Really enjoyed viewing and reading your project step by step and am very impressed with your knowledge, mechanical skills and attention to detail. Thanks,John

    Comment by John P — November 5, 2011 @ 12:11 am | Reply

    • Thanks for the comments John. I have a lot of other projects to post as well, if only I had more time to blog. I’ll get them posted slowly but surely, and hopefully you’ll find a few more that are enjoyable to read.

      Comment by nfluhart — November 5, 2011 @ 5:45 pm | Reply

  8. can u hear people talking on the cb radio while u are going fast down the road i might do the same thing but i don;t know if i will hear truckers Josh

    Comment by Josh Koetsier — November 25, 2011 @ 3:03 pm | Reply

    • It depends on a few thing…wind, exhaust noise, etc. If you have trouble hearing it, you’ve got a couple options. You can mount a small external speaker positioned directly toward you. There is a port on the back of cb and it plugs in. Or, you can use ear phones. Again, they plug right in the back.

      Comment by nfluhart — November 29, 2011 @ 10:44 am | Reply

  9. Nice job on the atv.
    I just picked up a 1988 moto 4. Like you i need to locate a carb.
    Any suggestions which carbs cross fit?
    Thanks.

    Comment by Tom. A — February 17, 2012 @ 12:03 pm | Reply

    • Thanks for the comment. Any of the 350 carbs, such as Warrior, Big Bear, etc. or the Kodiak 400 carbs can be made to work on the Moto-4 relatively easily. Most of the later model stuff (1990′s) uses a single throttle cable design instead of the dual cable setup on the older models, so if you find a single cable carburetor such as on a Warrior for example, simply use the Warrior throttle cable. It is long enough and it will hook into your thumb throttle assembly as they are identical. Same goes for the Big Bear and the Kodiak. Then it’s just a matter of jetting the carb to work on your Moto-4. I would buy a standard Moto-4 carburetor kit. It will come with the jets and everything you need. Those parts will make the fuel mixture compatible for your Moto-4.

      Comment by nfluhart — February 24, 2012 @ 1:30 pm | Reply

  10. You mention in the tear down “then the stator and case and of course the flywheel/starter clutch assembly (this requires a special tool)”. I’m trying to remove the same thing but don’t have the special tool. Do you have a picture of it, how to use it or know where to get one? I’d like to get one on Ebay, but haven’t been able to find one yet.

    Comment by Tim — March 11, 2012 @ 11:10 am | Reply

  11. I have picked one up as well i payed $30.00 for it it is all there except the carb and clutch/or break hardware for the left handle bar i have not really looked it over yet. I am how ever in the middle of another small project at this time. I am looking for a carb can you tell what will interchange with it?

    Comment by Tony — September 19, 2012 @ 2:22 pm | Reply

    • The early 350′s had a dual cable carburetor. They are hard to find. I sold my last one a couple months ago for $250. On my Moto-4, as noted in the post, I actually used a 350 Warrior Carburetor. In fact, any of the old Yamaha 350 flange mount carburetors can be made to work. The flange mount type are the ones that bolt to the intake boot on the head, as apposed to sliding in the boot and securing with a clamp. The clamp style can also be made to work, but you would need a clamp style intake boot as well. I used the Warrior throttle cable which screws right into the throttle with no modifications. However, you will want to use the Moto-4 jet size in any type of carburetor you use for it.

      Comment by nfluhart — September 20, 2012 @ 1:30 pm | Reply

  12. i am looking for a carb for the the same atv i pulled out of a field would you by chance happen to have another rebuildable carb you would be willing to sell cheap………. i cnat seam to gey the original type so i am willing to utilize anything i can to make it work. and if you have any ideas you can leave me let me know

    Comment by Anthony — October 7, 2012 @ 11:46 am | Reply

    • Unfortunately, I do not have a carburetor at this time. However, any of the old Yamaha 350 flange mount carburetors can be made to work. The flange mount type are the ones that bolt to the intake boot on the head, as apposed to sliding in the boot and securing with a clamp. The clamp style can also be made to work, but you would need a clamp style intake boot as well. Just use the appropriate throttle cable with whichever carb you choose. I used the Warrior throttle cable which screws right into the throttle with no modifications. However, you will want to use the Moto-4 jet size in any type of carburetor you use for it.

      Comment by nfluhart — October 7, 2012 @ 6:57 pm | Reply

  13. I really enjoyed all all of the information. I recently bought a 350 1986 moto 4 and the clutch has since stopped working. I have taken both sides of the engine off and found nothing wrong. could you let me know where the clutch is and if you know what i need to replace it, that would be fantastic. Thanks

    Comment by Greg — January 5, 2013 @ 11:08 am | Reply

    • The clutches are on the right side (from the seated operator’s position.) There are two, the long one with the steel drum is the centrifugal clutch. It engages the crankshaft to the transmission at a certain RPM via the main clutch, which consists of a series of disks stacked in an aluminum basket. The centrifugal clutch is what takes the place of a hand clutch setup as is found on a motorcycle, so instead of activating the main clutch with your hand, the centrifugal clutch does it automatically at a certain RPM. It’s not really possible to inspect either clutch without removal and disassembly. It can be challenging to remove the centrifugal clutch without prior experience (although sometimes they come off easily), but it must be removed first then the main clutch second. Although it’s not exceptionally difficult, it will be challenging to do this job without prior experience. There are many things to inspect.

      Comment by nfluhart — January 12, 2013 @ 6:59 pm | Reply

    • to remove the centrifugal clutch is the nut left hand or right hand and also how to remove it

      Comment by Rochelle Broussard — March 24, 2013 @ 10:16 am | Reply

      • If I remember correctly, most Yamaha clutches are right hand thread (Most Honda’s are left). If there are a few threads sticking out past the nut, you can trace them and see the direction.

        Comment by nfluhart — March 30, 2013 @ 5:44 pm

  14. Great job on the ATV. I have the exact year and model, but am having a tough time finding used parts for mine. Particularly, I’m looking for the rear disc and worm feed screw to replace mine. Do you have any suggestions for me to try?
    Thanks

    Comment by ncox2012 — January 13, 2013 @ 3:52 pm | Reply

    • Thanks for commenting. I checked my eBay store and unfortunately I don’t currently have a rear disc or caliper; they seem to sell fast. However, I would try looking around on eBay. I just saw a rear rotor and a complete caliper listed for reasonable prices.

      Comment by nfluhart — January 13, 2013 @ 5:12 pm | Reply

      • Thanks Nicolas,
        I love the ATV and really would like to get it going. Would you happen to know if there are other models that have the same rear disc? I’m hoping this would allow me to expand my search on ebay.

        Comment by ncox2012 — January 13, 2013 @ 5:22 pm

      • Per the Yamaha part number (21V-25711-01-00), the 200 and 225 Tri-Moto three wheelers used the same rear rotor. Also the 350 Big Bear up to 1995 used the same rotor. Hope that helps.

        Comment by nfluhart — January 13, 2013 @ 5:33 pm

      • Sounds good. I’ll give those a try. Thanks for the help.

        Comment by ncox2012 — January 13, 2013 @ 5:34 pm

  15. I have an 88 moto 4 350 and one of my lower throttle cables is bad. I’m wondering if you have one lying on the shelf or if you know where I can pick up an I expensive used one? Thanks.

    Comment by Brett — January 27, 2013 @ 3:59 pm | Reply

    • Unfortunately, I do not have one. Your best bet for a used one would probably be eBay. Otherwise, you may be able to find a new one at cheapcycleparts.com.

      Comment by nfluhart — January 27, 2013 @ 7:06 pm | Reply

      • I’ve been checking eBay for awhile now but haven’t had any luck. The problem with a new one is that they run over a $100. Thanks for the help. I’ll keep looking

        Comment by Brett — January 27, 2013 @ 7:21 pm

      • I found a throttle cable and have replaced it. Now the wheeler starts and idles fine but when I give it gas if will bog and backfire through the carb. Do you have any suggestions for me to try? Thanks

        Comment by Brett — February 17, 2013 @ 11:16 am

      • Sounds like it’s starving for fuel. I’d clean the carburetor and check the jets. That may solve it.

        Comment by nfluhart — February 17, 2013 @ 1:46 pm

      • Thanks for the advice. I’ll give that a try.

        Comment by Brett — February 17, 2013 @ 2:00 pm

  16. looking for the reverse shift lever assy. for a ’88 moto 4 350.

    Comment by Ron — February 4, 2013 @ 9:17 pm | Reply

    • Unfortunately, I don’t have one. Thanks

      Comment by nfluhart — February 17, 2013 @ 1:47 pm | Reply

  17. I found your webpage just by accident and I love your projects so much that I have already put you on on my “Favorites”. I’m not you normal follower though. I know nothing about mechanical things. My tools are baking pans, recipes and a nice stove to cook and bake in. I’m a 66 year old grandmother and I have a husband who has Macular Degenaration and has so much trouble seeing, but, he just won’t give up on trying to renew old vehicles, 4-wheelers and such. So, now I am his eyes and try to help him as much as I can with this ole 1989 Yamaha 350 Big Bear 4×4 he is trying to bring back to life. I read your “Project” pages like a novel and I get so excited when I can recognize a part, or just a tad, know what you are talking about. I told my husband that you were a genius. Thanks for the newfound enjoyment of living through your projects. The Moto-4 project turned out awesome.

    I do have a question: On our 1989 Yamaha 350 Big Bear 4×4 project, we are missing a Front Engine Motor Mount. I found one on ebay (another new quest in my life) but, it was for a 1992 Yamaha 350 Big Bear 4×4. Can we use that on our 89 model?

    Thanks,

    Grammy

    Comment by Rita Landrum — March 1, 2013 @ 7:19 pm | Reply

    • Thanks for your kind words and comments on my blog. I have a lot more cool projects to post, I just haven’t had much time…but hopefully I will soon. I think it’s awesome that you are learning about this stuff to help your husband. As for your motor mount question, just to confirm, the front engine mount consists of two triangular pieces of metal and three bolts. If that’s the mount you are looking for, the 1992 engine mount will fit your 1989 Big Bear. In fact, the same mount is used up to 1997 in both the 2×4 and 4×4 Big Bear models. Thanks again for reading and posting on my blog; I hope I’ve been able to help. Feel free to contact me any time.

      -Nicholas

      Comment by nfluhart — March 4, 2013 @ 11:29 am | Reply

  18. Thanks Nicholas for your quick response on my motor mount question. I really do enjoy spending time with my husband out in his garage. A person is never too old to learn something new.

    Do you know of any “How To” video’s in detail in regards to putting a “Back Differential” back together?
    This 89′ Big Bear was given to us, along with a lot of its parts in a bucket. Paul, (my husband) didn’t take this
    Big Bear apart, so he isn’t quite sure how it all goes back togethter. He did buy a service manual, and it shows the parts, but shows no detail in where it all goes back. He did buy a kit with some new “O” rings and bearings, etc. Thanks once again. Rita

    Comment by flgrammy42 — March 5, 2013 @ 6:18 pm | Reply

    • It may be difficult to find a detailed video, but I saw this guy on youtube: http://youtu.be/ApcD1gUN7hA . He may not have the same year model, but it basically works the same way. There might be other videos on youtube as well. If I remember correctly, the bearings will each fit only in one place, so that minimizes confusion. The seals may be the same way. If your pinion bearing doesn’t have slack in it and the gear teeth look good, I wouldn’t remove it, just replace the pinion seal. If your pinion bearing needs replacing, it requires a special tool to remove and reinstall the pinion spanner nut, but I’ve done it with a drift punch and hammer. Otherwise, it should be very straight forward. Check all the gear teeth for sharpness/chips and check the splines in the ring gear (that’s the most common failure). Your manual should have detailed instructions and most of them have an exploded diagram of the parts in their proper order. If not, you can view parts diagrams for free at Yamaha’s website, as well as partzilla.com, cheapcycleparts.com, bikebandit.com, among others. Worst case scenario, if you decide to have someone else do it, a competent ATV technician can put the differential unit together in an hour or so for a reasonable price.

      -Nicholas

      Comment by nfluhart — March 6, 2013 @ 5:11 pm | Reply

      • Nicholas, thanks for all your help. You have kept us motivated on this whole project on trying to put this 1989 Yamaha Big Bear 350 back together. We ended up putting the rear-end differential back together ourselves instead of letting a ATV Tech finish it for us. I’m glad we did, it saved us money plus, we would have missed out on all those bologna sandwiches and cold glasses of Cherry Kool-aid that my husband and I shared working in his garage. ;o)

        We finished up last night, putting it all together and my husband took it out for a trial run today. He was gone for an hour. I could hear him all over these West Virginia hills around our house. He had a great time. Thanks for your time you gave us. Keep up with your projects that you are so gracious to share with your Internet Friends. I know we love seeing them.

        Comment by flgrammy42 — March 24, 2013 @ 8:52 pm

      • Cool, glad you got it together and are up and riding. Just in time for spring. You guys have fun, and thanks for checking out my blog.

        Comment by nfluhart — March 30, 2013 @ 5:46 pm

  19. I’m working on my 89 Yamaha moto 4 350 that was given to me. I always had to pull crank it because the electrical wouldn’t work. I got to looking and there was no key switch so I bought one off ebay and plugged it in. Then noticed the neutral switch was broke so I replaced it. Now I bought a new battery and when I go to hook up the cables to the battery they spark and the motor tries to start. People have told me its either something is grounded wrong, the start button is sticking or it needs a new starter motor. What do you think? Need help bad
    -Justin

    Comment by Justin — September 12, 2013 @ 2:01 pm | Reply

    • First check the hot wire from the battery and follow it. It should not go directly to the starter, it should first go to the solenoid, and then from the solenoid to the starter. If that’s correct, the problem is either your solenoid or your starter switch. Easy to test…simply unhook the small wires on the solenoid (should be two, they go to the starter switch on the handle bars) and hook your battery back up. If it still tries to start on its own, your solenoid is stuck. If not, your starter switch is stuck. Hope this helps… -Nicholas

      Comment by nfluhart — September 18, 2013 @ 11:27 am | Reply

  20. Hey Nicholas,

    I commented last year asking your advice on my 1989 Yamaha Moto 4 350. Thanks for the feedback. It really helped. I am having another problem and that is with the reverse lever. The bike was slipping out of gear when going up a hill. I tried to tighten the nut on the lever, but it broke, so now I’m trying to find another. Here is a website that shows an image of what I am talking about: http://www.motosport.com/CA/atv/oem-parts/YAMAHA/1988/YFM350ER-MOTO_4/REVERSE-LEVER
    Anyway, I have gone online to ebay and see some potential parts, but they do not look the same and I don’t know what is interchangeable. Specifically I’m looking for the Reverse lever body and shaft. Everything else is ok. Any thoughts where I might find one or what interchangeable part might work (ie: something off a Big Bear???)
    Thanks

    Comment by pembycsi — January 3, 2014 @ 5:28 pm | Reply

    • I believe the Big Bear up through 1993 had the same reverse lever. In 1994 they moved the lever down next to the engine, but the older Big Bears had the lever up on the fender like the Moto-4. Your best bet will probably be to find a used assembly from a Moto-4 or a Big Bear from eBay. Eventually, something will be listed I’m sure.

      Comment by nfluhart — January 24, 2014 @ 11:13 am | Reply

  21. Thanks Nicholas,
    Do you know the torque specs for front end (replaced bushings and spacers and castle nut) and was wondering what torque specs were for reassembly.

    Comment by Jason — February 10, 2014 @ 7:24 pm | Reply

    • I don’t know the exact spec off hand. I’ve done so many over the years I guess I just have a feel for it, but most torque sensitive components are listed in the service manual. Thanks

      Comment by nfluhart — February 13, 2014 @ 10:21 am | Reply

  22. Nice blog!
    I am fixing up a 1995 Moto 4 and looking for a left front mud flap. Any more NOS in your shop?
    Thanks

    Comment by FKelly — February 17, 2014 @ 4:49 pm | Reply

    • Sorry for the delay in my response. Unfortunately, I don’t have any more NOS mud flaps. Keep an eye on eBay and something may come up. Thanks

      Comment by nfluhart — June 17, 2014 @ 2:25 pm | Reply

  23. Hey Nicholas,
    I ordered a wire control 1 for the reverse lever (the cable that runs to the switch for reverse and forward…see Reverse Lever schematic Yamaha Yfm350erw Moto-4 1989 http://www.partzilla.com/parts/search/Yamaha/ATV/1989/MOTO-4+-+YFM350ERW/REVERSE+LEVER/parts.html Part #22).
    This cable has a flange that allows you to bolt it to the bike frame. The problem is that there isn’t that assembly on the frame of my bike. I’m going to try and rig something up that would allow me to bolt the flange to a part on the frame. I don’t understand why this flange is on this wire control and can’t seem to find one like the original. Any ideas?
    Thanks Nicholas.
    Cheers,
    Nolan

    Comment by pembycsi — March 26, 2014 @ 10:03 pm | Reply

    • Sorry for the delay in my response. They used a few different shifter setups on these throughout the years they were made. Unless your flange mount on the frame has be broken or modified at some point, it sounds like either the schematic is in error, or perhaps you have a different year model than 1989. If you have an ’89 your tenth VIN character (from the left) should be “K”. You may try to view the schematics for a couple years before and after the one you’ve selected and see if there is a cable with the mounting like what you need.

      Comment by nfluhart — June 17, 2014 @ 2:31 pm | Reply

  24. Hi
    This is an amazing job that you did. I recently bought a moto 4 and had it running. I had to change the clutch on it as it broke. After I got it running it stopped dead ( after 100 meters) . The motor still turns over but does not start. I am going to replace the battery, and the spark plug. Have any other ideas of what might be wrong.

    Thanks in Advance.

    Comment by Greg — June 17, 2014 @ 11:45 am | Reply

    • Thanks for your comment. There are a countless number of things that can cause one to stop running. Much like you’ve said, always start with the simple stuff first. The battery generally won’t be the problem though, unless of course it is dead. But as long as the engine turns over promptly with the electric start, the battery shouldn’t be a problem. First, see if it is getting spark. If it is not getting spark, make sure your spark plug is good and then check the stator assembly (especially the ignition pickup) and CDI as those are the two most common failures. There’s a lesser chance (but still possible) that it could be the regulator or ignition coil. If you have good spark, check the fuel. Make sure all vent hoses are clear…otherwise it can cause a problem exactly like what you have described. Next, unscrew the bowl drain on the bottom of the carburetor and see if fuel comes out. If not, trace it back toward the gas tank and see where the problem is. Also check the air intake and filter. If all of this looks good, it may be sign of a more serious problem, and unless you are familiar with more advanced diagnostics, I’d recommend taking it to an experienced technician.

      Comment by nfluhart — June 17, 2014 @ 2:21 pm | Reply

  25. Nice project. I’m looking for a seat for a 1989 pro hauler, any ideas? Thanks in advance.

    Comment by Kent — June 20, 2014 @ 3:27 pm | Reply

    • The ’89 Pro Hauler uses a very unique seat and back. To my knowledge, nothing else interchanges with it. If you have the seat pan, I would have it re-foamed and covered at an auto upholstery shop. If you don’t have the pan, eBay is the only chance of finding one. Set an automated search to email you when one is listed, that way you don’t have to manually check every day…it will let you know when someone lists one. It also may be possible to build something custom for it.

      Comment by nfluhart — July 18, 2014 @ 8:31 am | Reply

  26. I have a yfm350 moto 4, can a big bear muffler fit over on it? i am working on restoring my moto 4 and would like more tips.

    Comment by James C — July 17, 2014 @ 9:36 pm | Reply

    • I’ve never tried putting a Big Bear muffler on a Moto-4, but it may be possible especially if you find a muffler the same year model as your ATV. At one time Cobra made an aftermarket pipe for utility ATVs that worked on a Moto-4 also.

      Comment by nfluhart — July 18, 2014 @ 8:23 am | Reply


RSS feed for comments on this post. TrackBack URI

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

The Rubric Theme. Create a free website or blog at WordPress.com.

Follow

Get every new post delivered to your Inbox.

%d bloggers like this: