My friend brought over his '04 wolvy; it has low hours. The problem was it wasn't running very well in the mid range. He tried cleaning the carb with carb cleaner but didn't take it fully apart.

SO I adjusted valves (intake was tight, and is now set at .003 thou), cleaned carb, removed all the jets, needle & seat, everything seemed really clean. I adjusted the mixture screw from 3 turns out, to 2 1/8 turns out. I'm a bit unclear on the slide mechanism install. There are 2 holes on the bottom of the rectangular piece that the slide sits in (one in the middle for the slide), but I wasn't sure if it mattered which way the unit went back into the carb. I just lined up the rubber diaphram/gasket to HOPEFULLY get it right, but it will affect which side the second hole lines up to. Does this matter? ALSO, I never touched the setting for the needle. Where do you normally set the needle?

I also replaced spark plug. Old one was black, and the new one is already looking kinda black.

The air filter had WAY too much filter oil on it. I tried to sop up and wring out as much as I could, as it was otherwise clean.

So here's the problem: it started fine and ran good at high RPM. In mid range, it was poor. THEN, i revved it and noticed a fair amount of smoke from the pipe. Some grey smoke, then maybe white (??) I wasn't watching the smoke that close.
Then it would stall when I held the throttle slightly more open than idle. NOW, it won't start. It might get a very short burp and then stall.

What am I missing here? WHat have i done wrong? WHat else could it be?

THANKS!!!!!!!!

 

Well, I decided to start by checking spark; looks good. SO I thought maybe something went awry with my valve adjustment, due to the clue of not starting. BINGO!!! The intake valve lock nut had come off. No idea how, since I defintely tightened it. I've done at least 15-20 of these adjustments before (on a variety of quads, including a different Wolverine), and NEVER had a problem. It took forever to fish it out of the side, but I found it. I used blue lock-tite and tightened it as much as a 10mm wrench can do. Hope it stays on this time. Hope this answers all my problems.

It makes sense now...once that valve opened up it would cause smoke. It only ran for about 2-3 minutes from the time I did the adjustment, until it wouldn't start. Would this cause any other damage? I assume the nut gradually loosened off until it wouldn't run anymore. Anyone else ever have the nut come loose?

 

now that sounds like a bigger issue than the P-break sensor but on a wolverine gotta check it first. There is a sensor that retards the spark when the parking brake is on but it can cause this to happen when the brake isnt really all the way on. its a switch with a little metal rod that goes into a cable and its mounted on the left hand brake. Personally if you havent already the best thing to do with the parking brake (cause it never stays ajusted for more than 30 seconds if you even try) is to buy a block off plate for on the rear brake disk, take out all the extra useless cable, and then trace the switch down to a white plug, unplug it and dont have to deal with the switch issue ever again. even if you dont remove the cable you can detach the switch, just make sure to seal up the open end of the plug thats part of the wiring harness so it doesnt get water and crud in it... Wolverine 350 is the best all around bike ever, better than the new 450 "wolverine" as yamaha likes to call it. if you/he have any questions about modding it or best products for it let me know mine is NOT stock. its my baby. had to sell one ATV to get the jetboat and I sold the quadzilla to keep this. not an easy thing to do after I spent 2 years refirbing the zilla down to many a little detail...


also did you buy it as is or was the filter recently added? anything else changed? if so did you re-jet. if you can get it running run some plug runs and check your jetting

 

well, put it back together and pretty much the exact same thing happened. It started and ran for a few minutes. got progressively worse, then wouldn't start. changed the plug and it was better, but then did the same BS again. So I AGAIN checked the intake valve. It seems to have loosened from the proper setting of 3 thou and is at about 5 thou. the nut seems tight. not sure how it would loosen off in a minute of running. I lock-tited it this time, too.

not sure if that much out of adjustment would cause all these rough running problems. ANYONE?? ANY IDEAS?? Compression is good,about 118-120psi.

 

can anyone help me here? Now it just won't start. It started great before. it's gone from rough running in the mid range, to basically not starting or running at all.

WHen a CDI is faulty, what kind of symptoms do you get? Could this be some other electrical issue?

BTW, I think i got the park brake safety disconnected.

 

Ned, I have a yamaha big bear 350 (1996), it does the exact same thing. I have listed the problem, but after 75 lookers, no one has responded. I have cleaned the carb multiple times but get the same response. I am going to try rotating the carb slide to see if that helps. Mine does'nt have that brake safety thing so I expect some CDI problem. But who want's to spend that kind of $$ if that's not it? If this has happened to others, they are abviously not on this forum.

 

kemo, I think our problem is we want it to be something mechanical that WE can diagnose and fix. When it comes to the electrical troubleshooting, it gets tricky and not as many folks know the answers. I have a Wolverine manual and it tells you how to trouble-shoot the various electrical components with an electrical meter, and what the resistance readings should be. So I'm going to try that, because without testing the various components, I don't think anyone can help us.

I did notice that my spark was probably a bit orange & yellow, and is weak. When I tried it UNGROUNDED, I had a great blue spark like a lightning bolt. So maybe I have a ground issue? I also heard that the pick up coil or source coil on these have been more commonly faulty. So I'll look at those too. I WILL post when i figure it out.

 

well.... I've been using a Wolverine manual on CD, given to me by a friend. Not sure of the years it covers. I'm told by friend that works at a yammy dealer that wire colors change year to year, as do the electrical component suppliers for Yamaha, thus the specs change for the different components too! So for electrical trouble shooting, you really need year specific info. Anyways, that doesn't turn out to be my problem.

So I put in yet ANOTHER plug, and it started right up. Same performance issues tho. good idle, revs on top end, but sputters in mid range, and still isn't right even at top end (way too rich). I keep coming back to air & carburation. I take carb apart and change jet needle position 3 times. also check air intakes and air inlet hoses; no obstructions.

remember, this quad came to me from friend who had taken apart carb and sprayed in some carb cleaner, then re-assembled it. I am very careful about taking apart and re-assembling EXACLY the way I find things, paying careful attention to whether things are directional, symetrical, etc.. I looked at schematic diagrams from my Wolvy manual. Oddly, in the Spec section they had an exploded diagram, and in the carb section they also had an exploded diagram of a DIFFERENT carb??!! (similar, but different, especially the jet needle configuration). I'm trying to see if buddy may have re-assembled carb wrong, but he said they never took out any jets, etc.. just sprayed in cleaner. I removed the "piston valve" at least 5 times. This valve has the big rubber diaphram cover attached to it. Each time I would turn it upside down and give a shake to remove the jet needle. WELL, the plastic spacer that is supposed to be at the TOP of the needle was somehow wedged inside the piston valve and diaphram. It had been re-assembled in the wrong order. It wasn't allowing the valve to move up enough to let air in, altho it may have worked sporadically which is why it would rev, then sputter, etc.. So a simple re-alignment of the spacers and it runs like new. And the lack of air/rich fuel was fouling plugs.

Now I'm beating myself up over whether I should have caught this earlier. well Yamahas carb diagrams aren't clear. Even a mechanic might miss this unless they are totally familiar with this EXACT carb, because they're all different. And If I took something like a carb apart and never told you what I did and left something tiny out, would you be able to immediately identify it? I think I did a good job to finally discover it. But it sure took MANY hours.

when I review this post, I see a few clues. fouling plugs, rough running= no air. SOMEONE ELSE took carb apart first...shoulda been more dilligent to make sure carb was reassembled properly. Hope someone benefits from this.

KEMO..check your jet needle configuration.

 

Just wanted to chime in and say thank you. I just cleaned and reassembled my carb on my '00 Wolvy and had this EXACT same thing with the same symptoms happen to me. This post came up in some searching I did and this detailed writeup saved me a lot of time and frustration.