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Currently working on a 1992 Yamaha Big Bear 350 that idles perfect but cuts out with any kind of throttle. We replaced carburetor and head to carburetor boot. Put in a new spark plug, the old one was black as hell, unsure if it was caused by old carburetor or current misfire. This problem similar to the rev limiter you see on newer models when differential is locked or in reverse. I don't think this machine has that feature but I could be wrong? I suspect an ignition component is breaking down but at the moment I don't have access to a wiring diagram or workshop manual but I'm working on that. Are the e-manuals any good? Any ideas?

I’m just wondering what year bike i got? it seems the vin has been rubbed off i got it from a auction here in Australia engine starts but seems has a dirty carb wont idle well and also has a problem I put it in gear and makes a grinding noise but does not move it the neutral light goes out but then when I change gear it grinds more in the higher gears as well I’m guessing the differential is stuffed so wanting to buy new part for it will start the pull down next week this is the first bike I have worked on used to dealing with cars

No spark replaced the coil and it ran good for a week now i have no spark again

View File 1987-1999 Yamaha Big Bear 350 4x4 Service Manual 1987-1999 Yamaha Big Bear 350 4x4 Service Manual YFM350FW YFM350FWT Submitter Samwise Submitted 12/04/2020 Category Yamaha ATV  

Hello All, I have a 1999 Yamaha Big Bear 350 4x4 trying to get fixed up so my grandson can go out in the woods with me. We have owned it over 10 years. It got harder to start, until it finally would not. Replaced the carb. Right afterwards, it started and ran nicely, but after turning it off, would not restart. Tonight I used starting fluid and ran, then died. Adjusted the idle up a little, used more starting fluid and ran great. It idled about 15 minutes. Turned it off, and restarted. Ran it around the yard about 5 minutes. Turned it off, and would not restart. Any ideas or suggestions would be greatly appreciated! Thank you.

Hi i bought my first atv last week, mostly for plowing. its a 94 yamaha big bear 350 4x4, with plow, new front axles, carb rebuild and some other stuff for $900. in todays prices, i think it was a pretty good deal. I plan on tearing it down and doing a semi restoration in the summer. its been clearly neglected so i suspect i will need to do a fair amount. couple questions. 1. parts and manuals, so far i know it needs front shocks, tie rods, brakes, cables, lots of small stuff, whats your guys favorite online atv parts store? where can i find a good repair manual? 2 - starts and drives great, shifts a bit hard? not sure whats normal because i dont have a point of referance. i have to almost lean back in the seat and lever my foot up to get it to shift, seems like there is either alot of play in something (shift lever itself is tight) or there is a long travel, or it just dosent want to shift. also the hi / low / reverse lever needs to go past the gate a bit to actually shift into gear, and seems to need me to shift into nutral before shifting into reverse (not sure what your supposed to do). also wondering a bit about the history of the machine, because the plastics have a slot for a dash mounted shifter, but the one on it is a gated shifter right above the pull starter. 3. seat and plastics repair, seat is quite torn up with a seat cover over it, plastics are pretty cracked up, these items i havent found replacements for for any reasonable price, i dont care a whole lot about asthetics but whats the best way to functionally repair these things? is there reasonably priced replacements somewhere? i plan to bedline the whole thing after im done. 4. there was no title, but i did get a bill of sale, will it be difficult to get it titled / registered? (im in mn) thanks in advance for your help, looking forward to being part of the community

Hello I am new to this site and I havea problem. I have a 1987 big bear 4x4 that will not spark. I tested pick up coil per repair manual and I tested my new coil both ok. It puts out 9 volts at the coil but It is reversed polarity. So when I hook my meter up to it she shows -9 volts while cranking. When I put a test light on it it flashes. Being an electric system this should tell me something but I don't know what its telling me. I have yet to meet one i could not fix but this old girl has me stumped. Any help would be awesome. Thanks to all. Nick

Can somebody help me on my issues? i bought new stator for my 1987 big bear 350 4x4, (1) it seems that the old owner replace the pickup coil with same color aftermarket pickup coil, i got no idea which pickup coil goes where on 2 spot, new stator have the right colored wire for each pickup coil btw, (2) new stator got brown and green wire connecting to cdi but my cdi got brown and red, anybody got idea if brown go to brown and green go to red? Thanks

I took front brakes apart recently and found pistons frozen in calipers. Havent been able to find cheap calipers for this bike

My father-in-law gave my boy a 1999 350 Big Bear. It's been sitting in a barn for a bunch of years. It runs great! My boy has been riding a couple weeks now and it has developed a squeal coming from the front end when you get off the gas at speed. No noise during acceleration. At first I thought brakes. I took it for a ride and I don't think it is the brakes. I feel it is the front prop shaft U-joints, front differential or one/both axles. I pulled the fill plug on the differential and I can't find anywhere how much gear oil should be in there. My gut says up to the fill opening. It doesn't have a manual. It's wet in there, just don't see any gear oil. #1 Should I fill the differential with gear oil up to the fill opening? #2 How do I check or know if the u-joints are bad? That looks like a "Big Bear" of a job if they don't need to be replaced. #3 What else could it be? I don't think it is the front bearings. I jacked the front wheels off ground and no play in the right wheel. Very little play in the left wheel, looks like the lower control bushing is where that play is coming from. The rubber CV boots look original but all still intact. Wheels spin easily without any noise. Thanks for any help!

I picked up a 1997 Yamaha Big Bear 350 2X4 a week or so back in non running condition, apparently they said it needed a new carburetor or a battery, I cleaned the carburetor thoroughly and got it running on idle and without choke now and it shifts into all the gears even into reverse. Aside from making me bounce a little when trying to start out with a bit of throttle the shock suffice to say needs work. Anyways I made a video of it running and would like your opinions on it, as to how it sounds while running. It seems like it has a little whine I'm not sure why that is maybe someone can tell me what it is. Anyways here is the video.

1987 YFM350FWTB 350 4x4 Big Bear when going uphill will sometimes act like the clutch realeases then re-engauge all at once. Seems to maybe be little more often if the engine is at about 1/2 throttle instead of at lower rpms. I have the Factory Service manual and checked the external clutch adjustment screw as ok and the H/L/reverse shifter lever linkage as adjusted correctly. It appears to be maybe a internal (inside the case) clutch issue or ?? This is the type Big Bear that has the manual shift lever on the left front fender and has the manual foot shifter lever with 5 speeds forward. Can someone tell me how the primary and secondary clutch operates? I assume one is mechanical and one is centrifugal. (what I'm asking is one clutch for the higher rpms and one for the lower rpms or ???. (the clutch appears to only momentarily release at the higher rpms is why I ask. The cycle has about 3000 miles of low speed through the brush hunting and has been well maintained, oil changed, etc and no deep water or mud useage. Anyone been into a similar issue with the big Bear ATV????

My old Big Bear nearly left me stranded but I managed to limp back to my garage just before it died. Now No Spark. I’ve changed the obvious, inexpensive and easy parts- spark plug & coil without any luck. Ive stripped it down and traced all of the related wiring, checking as many connections as I can but no luck again. Next I pulled the cover and accessed the stator housing to inspect and do some resistance testing to ID a possible short. Here are my readings: Source coil- 325 ohms Pickup coil- 225 Can anyone tell me if these are good numbers, and if good, where to go next? I assume my next purchase will either be a new stator or CDI, but since neither of these tend to be returnable items I want to be as sure as I can I’m gonna get a resolution to the problem!! Thanks, Gary in SC

I have a 1988 Big Bear 350 4x4. I had to take apart my front brake pistons and thoroughly clean them. The internal gaskets appear new from when I had bike shop I thought do a brake repair. Seems like they just replaced gaskets and didn't bother cleaning or clearing any of the trash from system. I put everything back together and try bleeding system and pumping up brakes. The front piston on both sides will just barely build up and it does hold and when I bleed them I get a solid stream of fluid so don't believe there is any blockage. Also to note the bleed valve is after the rear piston on each side so fluid is reaching it but for some reason not building pressure I'm guessing. How can I tell if I need to rebuild my master cylinder ? Pic - the piston on left is before and right is after I cleaned one.