03 Yamaha Wolverine needs more torque in First.

[wirespider]

Outlander,

I got home early enough this evening so I drained the bowl and ran it into the woods and soon enough (after doing some rock and log crawling) it started acting up. This time I thought I was gonna need a tow out as I was playing in a steep ravine with no low end power but I spitter & sputtered my way around the climb out.

So I loosed the boots, spun the carb around and took off the bowl. I couldn’t see any build up on the float valve (needle) like some do. Although those parts can just wear out and still look good as I’ve found out in other mechanical adventures.

I did notice while messing around that when I hit the throttle a good bit of gas sprays back into my air box. Also, the breather line from the carburetor to the head was full of gas. Is this all normal?

The main jet is a 160. Does anyone know if that’s stock or if someone stuck a bigger one in?

Anyhow, I did adjust the flaot a tad but it didnt help as I took it out again..

So still clueless...but hopefully getting closer to an answer…

[outlander560]

damn i thought that would of helped a little... i dont know jet sizes that sounds a little to big see ur manuel or ask ur dealer wat size the stock one is... gas in the air box is not normal.... the carb might be giving to much gas to the engine causing it to bog down at such low rmps...because the engine isnt working as fast wen it is in 4th or 5th... those are for top speed right?? now its only in the first and second gear when ur getting this bogging down right?? it might not be getting enough of air to gas ratio... also the jet should be adjusted to ur elevation...

[wirespider]

"the carb might be giving to much gas to the engine causing it to bog down at such low rmps"

ya i follow ya outlander, but wonder why it has to heat up before it acts up? or is it just taking a while to load up the breather hose and such. when im in the woods, im only in first or second then after a little bit of playing (like 10 minutes) it starts to miss and cut out on me something fierce unless i can get it out of the woods to get the machine geared up, then it clears right up (but i cant go back into woods with any low end rpms without first letting it cool down).

Still has me confused as I think its still heat related because if I leave it cool down it’s a brand new machine all over again (then again it could just be that the gas is somehow clearing out) sh** I dunno.

The carb is a Mikuni BST34/1 the manual doesn’t list the jet but I looked on the net and only found a few that where put on different machines and one had a 162.5 stock main.

[outlander560]

ok well then the jet isnt the problem but wen u say it overheats and then wen it cools down it brand new again that gets me wondering.. is ur atv oil cooled or air cooled??? u got the machine used right?? did they tell u how many miles were on it???

[wirespider]

ok well then the jet isnt the problem but wen u say it overheats and then wen it cools down it brand new again that gets me wondering.. is ur atv oil cooled or air cooled??? u got the machine used right?? did they tell u how many miles were on it???

No, they didnt know how many miles or hours where on it (1 owner). Not one break in any of the plastics but that doesnt tell me how hard it was ran. The engine is oil/Air cooled as the air cools the oil cooler on the front. The oil light passes all the inspections to see if its functioning right and it hasnt come on yet. but ya the block and crank case gets hot as hell but to some extent thats normal, no? it doesnt smoke at all and I dont loose oil.

If I wasnt such an optimist id swear that 4 stroke is overheating...but its not really showing much for symptoms except maybe for the reason why im here.

Also, when your in the woods theres not much of a chance for the air to cool the oil cooler. but still, i could see it if i was on it for a couple of hours in the woods.

[outlander560]

im leaning more towards ur carb then anything.. but thats just me.... it might be giving the engine to much gas causing it to act up... but im stumped...

[wirespider]

"but im stumped..."

Don’t kick yourself over it though outlander. To be honest this is the best dam forum on the net when it comes to atv advice as I posted this on a few others and maybe got 2 responses. At least you and others took a proactive position on this problem and divulged yourselves deeper. And for that I thank all of you

I'll let you know when the coil arrives if that helps.

This is probably a long shot but does the CDI on this machine kill it when it acts up or could it be heating up then acting up then maybe cooling off when I get out of the low end?

I only keep at this cuz I know I might as well by a new one instead of taking it back to my dealership (stealership) especially since they couldn’t fix it the first time.

[outlander560]

well thanks im glad that i helped but i would be happier if it was fixed so im gunna be brain storming..... and hopefully i will come up with more advice.... is their any other symptoms ur atv is showing that shouldnt be

[wirespider]

Well, at out curiosity I decided to leave the woods after playing a bit last night and ride a few hardtop roads for about 20-25 minutes (there’s a lot of township roads where I live). I noticed that it does have a decent top end and is a really smooth ride. But...it definitely has a low rpm miss to it, i.e. when I was in 4th and needed to be in 3rd it would have a miss (Nothing that couldn’t be cleared out by upping my rpms)or in fifth and needed to be in fourth.

That’s most likely another symptom that’s tied into the other issue that this beast is having.

Also, I think most CDI boxes heat up if they’re going bad. I checked the box after ridding a while and it was pretty cool to the touch (definitely not overly hot).

[SunLrider]

"but im stumped..."

Don’t kick yourself over it though outlander. To be honest this is the best dam forum on the net when it comes to atv advice as I posted this on a few others and maybe got 2 responses. At least you and others took a proactive position on this problem and divulged yourselves deeper. And for that I thank all of you

I'll let you know when the coil arrives if that helps.

This is probably a long shot but does the CDI on this machine kill it when it acts up or could it be heating up then acting up then maybe cooling off when I get out of the low end?

I only keep at this cuz I know I might as well by a new one instead of taking it back to my dealership (stealership) especially since they couldn’t fix it the first time.

thanks man. we really appreciate it:wink:

[wirespider]

Another symptom:

When clearing the trottle out when its acting up it will throw white smoke from the exhaust.

[outlander560]

well u might have tom much oil int you engine... or wat i think might be happening is that ur rings on ur piston r going...idk... my 2 cents.. maybe ur timing is off to

[atvredefined]

in most cases if the timing was off it would backfire but at this point it wouldnt hurt to check. maybe ur valves arent seating properly.

[wirespider]

The valves might be it, I could see them somehow getting hot and not seating (hell they might need adjusted as far as I know since the dealer was told to do it when they had it and they didn’t do sh** really:skeptic:). But the oil is pretty fresh yahma lube with only cpl hours and the level is good.

I could see the timing doing it as I’ve seen this on vehicles after it warms up (but ive never timed a 4 strike bike engine).

The piston ring doesn’t make sense to me as it only does it when it starts to spit and sputter really bad and its only when I clear the throttle out (not like its smothering the combustion with oil as its not that bad of a smoke cloud) plus it should be smoking like a train when I have it wound out tight or just playing with the throttle before it starts acting up. Although I could be wrong, hence why I joined a forum like this as my knowledge of 4 strokes is very very limited:confused:

At this point I would tear it down and rebuild the carb and rings and whatever.

If the lobes where bad on cam it should do it on startup I would think. So I think the cam should be good, no?

OK, so if it was you guys machine what all would you rebuild. Remember I'd like it to be as close to stock as possible when done (I dont need anything else to kick my as* with, as my knee is just now healing after my YZ kicked me off of it a week ago).

Plus, where can I get timely parts. That ignition coil still hasn’t arrived from one of theoutdoornetwork owned sites. I usually get them from my local Yahmaha dealer but I think after this experience with this wolverine they've seen the last of me.

Give me a practical list of what all it could be guys and I'll gather the parts and do it.

This is as good as time as any to tear down my first 4 stroke. kinda weird I haven’t yet since I’ve rebuilt 2 strokes and 305's and a 351W (think ive heard "its not worth the trouble" too many times when dealing with 4 strokes)

I’m tired of this thing acting up I want to play on it when the snow starts to fly, which is not that far away.

[atvredefined]

i really dont think its ur timing, is it the air or liquid cooled?not sure wat yr they switched

[wirespider]

i really dont think its ur timing, is it the air or liquid cooled?not sure wat yr they switched

C, this is why I love this dam board. No one jumped on my sh** by saying "well technically if you rebuild a car engine you have rebuild a 4 stroke", thus stroking their fragile EGOS. I was waiting for it…

First post was a constructive post. HELL YEA!

Its oil/air cooled as it’s cooled by oil that’s run through an oil cooler that is cooled by air.

This is really gonna seem coincidental but I ran that beast some last night in the mid 40's here and it ran pretty good. Acted up some but it seemed to "Cool" down quicker. I’ve checked the oil light and it works (sensor could be screwed up I guess) No Oil leaks as I sit it in my garage allot of nights.

[wirespider]

Took the oil check cap off while running and the oil spit out pretty good. That at least tells me the oil pump is working. How well I'm not sure.

[wirespider]

finally got that coil in the mail. since it came without a cap, i'll have to put one on the wire. Then i can finally rule at least one thing out, if it doesnt help...

[dirtdevil96]

finally got that coil in the mail. since it came without a cap, i'll have to put one on the wire. Then i can finally rule at least one thing out, if it doesnt help...

Any current updates?Did the new coil fix it?