I have a 94 Sportsman 400 4x4 - what started out as an electrical problem according to the shop is now maybe a carb problem.

I had the ETC switch in the throttle replaced, speed limiter switch replaced. It now runs ok once you get the rpms up but it just won't idle normally. I have to have the idol screw all the way in and it will just barely stay running - it will actually stall after the engine is warm. I have taken the carb total apart and cleaned all jets and ports with carb clean - it didn't make a difference.

Could this be a shot carb? Could it be a bad coil? Anything else?

Any help would be appreciated for this forum newbie!

Thanks,
John

 

Sounds like the pilot jet is stopped up.If that isnt the problem run a compression check you could be low on comp it needs to be at least 110psi

 

Well - I've taken the pilot out and sprayed all the ports out. I sure hope it isn't the compression. If the compression was bad wouldn't that cause problems on mid and top end of rpms also - it seems to have plenty of pep and power if you get on the throttle.

Thanks for the help - I'll have to check the compression just to be sure.

 

Did you make sure you could see through it end to end not just the side holes? Bad comp will ussualy be accompanied with hard starting.

 

Could have swore I could see all the way through it - I will double check. I'll also check the compression just to be sure.

Thanks for your ideas!

 

Your problem sounds similar to the same one that I just had with my 99 Sport 400.It was hard to start, wouldn't idle without the choke on and with the choke off the idle would speed up and then the machine would just die.My problem turned out to be a split in my carb abdaptor.The carb adaptor is the rubber piece that connects the carb to the reed cage and has the oil injection going into the side of it.

It may be a long shot, but it's worth checking out.

 

WaaHeHe94 - i did check out that boot - I can't see any holes or cracks. The problem with my machine is that I can't get it to idle up any faster. It idles real slow and no matter what I do with the idle screw it doesn't make a difference. The only way to get it to idle faster is to put some pressure on the throttle.

ftwflh - I did take that pilot jet back out and make sure it was clean all the way through. I did find a small bit of crud but it didn't make a difference once I put it back in and started it up. I also wanted to test the "new" etc switch they put in it. I took the throttle cover off, revved her up a bit, held the cable with my figure and let go of the throttle lever. It made contact with the etc switch but didn't make a difference in the rpms. Does that mean it is good or bad?

I didn't have a the gauge or the chance to get the compression checked.

Do you think it could be a bad coil? Not getting enough juice on the low end?

Thanks for all your help!

 

I've got the same problem with my 400. Will not idle until you just touch the throttle. It runs great after that until you let it idle again. Another thing I noticed is that mine will not start unless you use the choke no matter how warm the engine is. The carb is clean as a whistle. Havent checked the compression yet but will do so and get back to you.

 

Mine is doing the exact same thing. I have to touch the throttle just a little to keep it idling. I messed around with the throttle freeplay, and got it to idle without hitting the throttle, but it idle'd way to high, so i set it back down. I am 99% sure that mine is not compression, because I just rebuilt the top end around janurary. I replaced the reeds and reed gasket last weekend, and that didnt make an difference. Mine has also messed up a few times while running, it would cut in and out for awhile, and then run ok later on. [img]i/expressions/face-icon-small-confused.gif[/img]

 

Well - I finally checked the compression on this 94 Sportsman 400. It is at 100psi. Is that good enough? Or should be at the 110 or higher that is mentioned above?

I just had the carb in the shop and the mechanic said the carb is fine - clean & good jets.

Thanks.