Hey all. Had a question about my new wheeler. It is a 1994 Polaris 400l 2x4. Has a new top end. I got it knowing that it would not idle. Figured it was the crank seal. It would rev when sprayed so I knew it was part of the problem. I put a new one in today. No change in proformance though. It will start with the choke on and will run on full throttle just fine, but it dies very quickly when you let go. Some times if you try to let it off real slow it kinda idles for a second and then without touching the throttle it revs waaaay up and dies. Seems like it is leaning out. Not sure what to do. I have cleaned the carb twice. Check the intake boot. Tried with air filter tried it without for kicks as well. No difference. Any guesses?

I was thinking maybe a new carb. Any other ideas would be appreciated. Thanks

 

did you check both sides of the crank? theres one behind the clutch and the flywheel. also try to wiggle the crank. if you feel any movement that means the bearings are bad. no matter how pliable a seal is it cant keep up with a sloppy bearing.

 

It should be smoking like a bugger if its the other side. It would be sucking in tranny fluid. I guess I don't know what kind of running symptoms this might cause. I will go look that up though. I got the seals in a package so I have the other side,but I figured why bother unless it really needs it.
It won't even start unless I have the throttle half way. In fact it starts fast if I pump the throttle instead of keeping it in any particular place. Go figure.

 

I got a new/used carb, cleaned it all out and put it in. It helped, but did not solve the problem. By loosing the nut on the choke, and screwing it out a bit I can get it to idle pretty good with the choke off and the throttle down. However if I run it it will take awhile to get back to idle, just a few seconds, but longer than it should. Also It still revs way up sometimes after I let go of the throttle. It seems like it has some sort of weird air leak somewhere.

What are the chances that there is a leak on the head itself??? Would it even run? Where else could it be leaking from??? This is starting to get old. Oh well it is still kinda fun, I don't mind it being broken, I just wish I new what it needed to be fixed.

 

when you loosened and moved the adjuster you just activated the choke without moving the lever. after the get this issue resolved you will have to reset the choke or it will load up on gas. I also believe that you have a crank seal leaking, could be a crankcase half leaking. if it was a head leaking there would be coolant in the cylinder or running down the side of the head. how many turns out is the pilot screw?. did you remove pilot jet from the carb?

 

CHANGE THE CRANK SEALS ON THE OTHER SIDE!THERE IS NO OIL ON THAT SIDE FOR IT TO SUCK IN AND SMOKE.Counterbalance oil is seperate from the crank

 

Sorry its been awhile since I have had time to mess with this. I replaced the crank seal on the other side now. So new crank seals, different carb, I can spray carb cleaner all over it when it is trying to run and it doesn't rev, so I am going to assume that means there are no air leaks. But it still won't idle. It is running just like it did before I did anything to it. The head was rebuilt, is it possible that I need a larger pilot jet? This thing is getting on my nerves.
Thanks guys.

 

Check the pilot jet.It is what controls the low end of the carb.Clean or replace

 

It may be as simple as a bad choke cable or out of adjustment cable.........Maybe you THINK the choke is off .....But the cable may tell otherwise..............

Sometimes the cables will fray inside the housing and get hung up!.........I had one on a snowmobile throttle fray inside the housing and the throttle would stick....Needed to jam the throttle lever down to the handlebars very quickly to release the tension...................replaced cable then fine.........You can't see the entire cable for wear when inside the housing.........Caper........