4wheeler help...

[jfowl31]

OK, I bought a bit of a project 4wheeler to play with and use at my deer lease. Its in good shape cosmetically, but it has/had a few issues.

First, the front brakes weren't working... got that fixed.

Second was new rear tires, and soon enough new fronts because it looks funny with 2 new and 2 old.

NOW the problem is motor related. Sometimes it runs like a bat outta hell, sometimes it bogs down BAD. For instance, I'll run it through the gears, and slow back down, then try to hit the gas again (in the appropriate gear of course) and the motor will just sputter and eventually die if I keep the throttle pushed. It will idle, but won't rev. Sometimes I can play with it and get it revving again after a few minutes, sometimes I have to let it sit for a while.

SO... I thought it must be heat related... nope, sometimes it does it straight from start up.

Then I realized when its sputtering and bogging like this, I can choke the motor and it will idle higher and let me rev it.

SO... here's where I'm at. Since it runs when choked fine, it sounds like its getting too much air and not enough fuel to the carb. I'm thinking dirty fuel filter, or possibly just gunk in the carb. But it seems odd that it runs great sometimes and not others.

I've got a guy who will work on the carb for me, but I would just as soon do it myself, and learn a little bit in the process.... BUT I don't want to make matters worse trying to keep it in house. So far everything has been done on a good budget and I would like to keep that the case.

Its a Kawasaki Bayou 300 if anyone knows anything specific to take into mind with the make/model. I think its the Rancher model or something... 2 wheel drive with a manual locker for the differential. Once I get it running right all the time, I'll build a trailer for it and make it a really nice work horse for the lease as well as good transportation to and from the blind.

[QuickDrawMcGraw]

J check the air filter and make sure its clean and the box it sits in is dust and dirt free. Also if the filter is dirty it will make it run like the choke was in and therefrore make the plug real black from running rich . A new plug aint much money and its good to start fresh . Check these and let me know how you made out .

[rep30cal]

From my past experience with dirt bikes and one that did that very same thing about six months ago, check the pilot jet for debris. This bike had a small piece of dirt that wouldn't pass thru the jet and caused this same problem but must have been able to work it's way out of the way to sometimes work fine, actually looked like a small grain of sand.

[rustypirate]

I would also flush the fuel system, tank and all.

[pgp888se]

i agree that the carb needs to be checked for debris.did this thing sit for a long while? if so it may have a varnish biuld up that causes the float to stick keeping the needle and seat closed.hope you get it taken care of.

[Bad Monkey]

I agree with checking carb. but before I would take the carb. off I would take a can of starter fluid and spray around the base of the intake/carb. and see if it idles up to make sure the intakes doesn't have a small leak.

[jfowl31]

Well, got a chance to run it for a while yesterday. Same old story. I ran some Berrimans Chemtool through it hoping to break up and run everything thru... no dice. It would run like crazy for 5 or 10 minutes and let me run 50 mph or more, then just as soon as I decided to stop for a second, it would go back through its routine...... time to pull the carb I guess.

I think I'll just get a rebuild kit for it and replace all the seals and everything while I'm in there. Is there anything I should pay attention to before I go tearing into this thing as far as the jet screw or anything like that? Any secret tips for getting everything back to where it should be?

Oh and I ran the tank completely dry and added fresh gas with octane booster yesterday too. Hopefully that got the rest of the crud out of it. I'm sure it sat for a while, it belonged to an old man out in the stix who had 3 other 4wheelers that were MUCH newer. This one is very well maintained it looks like, I think it just sat for too long after he bought the new toys..

On a side note, this thing is fast as crap for a 300cc motor. It feels and pulls more like some of the 500s I've run on.

[turmanator]

Those carbs are horrible about the shellac from the old gas plugging up the fuel and air jets and passages from sitting...... a can of carb cleaner with the little straw does a pretty good job ... and a needle or thin sharp object ...

[jfowl31]

I think I'll tear it down tonight and clean it up nice.

I've got a rebuild kit on the way that I'll throw on once it gets here. In the meantime, I really just want to get it running right so I feel better about buying it. I assume I'll have to clamp off the gas like or something? Or drain it into a gas can I guess would be a decent option.

[SSwee]

Besides what has been mentioned, you may need to check if the tank is venting. Usually done by popping the cap loose when it malfunctions and see if the engine will accelerate normally after a few seconds. I've run into this problem a couple of times.
SS

[jfowl31]

well....... I pulled the carb and bought a rebuild kit for it.

same issues..... I pulled the air filter, ran it... same issues... cleaned the air filter.... same issues.

Its weird because it will run great then run like crap...

[SSwee]

If the carb is clean and it runs better choked, did you check the fuel tank venting?
SS

[jfowl31]

The carb is clean now. It won't run choked now though, but its still bogging down sporatically. I can run a lap around the block and all seems well, but then if I stop, it won't rev, and bogs down and dies if I touch the gas. If I let it idle for a few minutes, it will rev again, and be ok. Run another lap around the block and then the same thing happens again.

The tank is venting fine, and it still bogs even with the cap off. It still bogs with the air filter taken off (not a clogged filter).

The only other thing I know to try would be to change the oil. I got to thinking maybe its overfilled with oil and so when it runs high RPM's for a while, there gets to be too much oil in the top of the motor which bogs things down maybe? I'm going to drain and change the oil, and probably do the same with the gas again, and if that doesn't fix it, its going to a small engine mechanic as I'm totally lost with it.

[86thecat]

Sounds like a sticking float or debris under the float needle. It's been a while since I messed with motorcycle carbs, they still have floats, right?

[sbw9056]

Does it have a fuel pump?