Quad - Yamaha Beartracker

Sami23

Not sure if this is the right thread for this but I'll chance it anyway.
My quad was not used for a few months and now when I start it with the choke out fully (usual starting position) it revs up to maximum and when I push in choke it cuts out. (also cuts out on half choke)
Can anyone tell me what the problem could be, I was thinking something is stuck in the carb. ?????

reilig

Sami23 wrote: »

Not sure if this is the right thread for this but I'll chance it anyway.
My quad was not used for a few months and now when I start it with the choke out fully (usual starting position) it revs up to maximum and when I push in choke it cuts out. (also cuts out on half choke)
Can anyone tell me what the problem could be, I was thinking something is stuck in the carb. ?????

Is there old petrol in it? Could it be gone off?

Timmaay

Have one of those beartrackers also, and use to have this problem, took me a while to get to the bottom of it, but I don't think it was one single problem. 1st thing I'd try is fire in a new sparkplug, the one in it is still working obviously, but they can go weak, and misfire abit, and if the mix ratio is off any bit the quad will have trouble staying running. Next thing is screw in the idle screw a turn or so, (its a little black plastic nob on the bottom of the carb) this should at least let you use the quad with the choke in the whole time. Be careful not to screw it in too far, or it will idle too high, and drag on the centrifuge clutch.

Dirt in the carb is another strong possibility, which will throw the jetting abit, unless you have looked instead a carb before I wouldn't bother messing with it trying to clean it yourself. Any mechanic will be able to clean out the carb, and check the jetting for you.

Sami23

reilig wrote: »

Is there old petrol in it? Could it be gone off?

Yes the petrol would be old alright.
Wonder could this cause the crazy reving and cutting out ?
It starts no bother even after being parked for few months.

Sami23

Well lads, believe it or not I only got round to workin on the quad last w-end.
Anyway I took off the carburetor, stripped it all down, sprayed everything with carb cleaning spray and carefully put it all back carefully. Cleaned out fuel tank and put new petrol in. 
Unfortunately the same problem exists. It starts easily on full choke but immediately revs very high resulting in the exhaust pipe getting red hot coming out of the engine. On full choke the accelerator works fine albeit pretty much full throttle
When I go to half choke or no choke the bike cuts out straight away.
Can anyone please suggest what the problem is or what I can try next as I have no idea as I was sure the carb clean would work.
Thanks

Timmaay

Sami23 wrote: »

Well lads, believe it or not I only got round to workin on the quad last w-end.
Anyway I took off the carburetor, stripped it all down, sprayed everything with carb cleaning spray and carefully put it all back carefully. Cleaned out fuel tank and put new petrol in. 
Unfortunately the same problem exists. It starts easily on full choke but immediately revs very high resulting in the exhaust pipe getting red hot coming out of the engine. On full choke the accelerator works fine albeit pretty much full throttle
When I go to half choke or no choke the bike cuts out straight away.
Can anyone please suggest what the problem is or what I can try next as I have no idea as I was sure the carb clean would work.
Thanks

God how time flies by ha! I still got mine also, it's been through the wars but I still can't justify flogging her on ha. Anyways did you try the plug?

Sami23

Timmaay wrote: »

God how time flies by ha! I still got mine also, it's been through the wars but I still can't justify flogging her on ha. Anyways did you try the plug?

Yeah there a good yoke wen there goin alright.
Yes I put new plug in too so don't kno what to try next

old deere

sounds to me like its drawing air somewhere between the carb and engine. check gasket,any screws missing,any crack in manifold

Sami23

old deere wrote: »

sounds to me like its drawing air somewhere between the carb and engine. check gasket,any screws missing,any crack in manifold

Thanks old deere, I'll b having another go at it this week. Will clean carb again and check what you suggested

Timmaay

Timmaay wrote: »

God how time flies by ha! I still got mine also, it's been through the wars but I still can't justify flogging her on ha. Anyways did you try the plug?

Just priced up a new 250 Honda quad here, 6k and I wouldn't get a whole lot for myown, 500ish. Think I'll be fixing my up instead ha.

Sami23

Well lads, believe it or not I actually got her going again yesterday. I stripped the carb again to clean it and spotted a jet I had missed 1st time round. It was located deep in a hole between the main jet and the idle needle. I think its the pilot jet but could be wrong. It was fully blocked so she hadn't a hope of going right.
After putting her back together she actually started with no choke after a couple of years sitting there which pleased me.
I took her out of the shed and gave her welly down the fields for a while and she's goin mighty.

Only dodgy thing is she is a bit up and down on the idle revs. I got off to open gate and left her in neutral and she proceeded to race alot then return to normal then race again etc.
If I leave her in 1st with break on she ticks over perfect.
Wonder what might be causing this irregular idling ?