90 arctic cat prowler snowmobile question....dies at full throttle

[IC Smoke]

Hey guys,



This is a little off topic but I just picked up a 1990 Arctic Cat Prowler snowmobile 440 dual carb. 3800 mi lady owned



Its has new 93 octane fuel, new plugs, I pulled the carbs and tried to get the bowl off the bottom but it wouldnt come (4 bolts removed and tried to pry it... nothing) so I sprayed carb cleaner into it, up thru the bolt in the bowl (did this to both)



Took it back out and it runs a little better BUT it still dies and it has to run on half to full choke, if you put it on NO choke it stalls, even on choke you cant hold it full throttle ALSO you must feather it a little to get up to its max speed so far of 45 mph (that ive been able to reach) also it has no gutts getting up hill and I have to get off and push/ run with to get up the steeper inclines.



Any ideas guys? Thanks!

Ian

 

[mgoncalves]

Sounds like the main jet is clogged pretty bad, you'll have to get the bowls off somehow.

 

[SGibson]

It's running way lean

 

[B.G. Smith]

As stated above, not getting enough gas. Don't run it like that as you can burn a piston if you get enough humidity. It could be the supply to the carbs, try removing the fuel line to carb and see if it is restricted/plugged filter, etc. Also could be the main needle adjustment or float level adjustment if someone who was unfamiliar with it has been working on the carbs. You can check the main needle setting by removing the screwed top from the carb an lifting the piston valve assy. from the carb. If the clip on the needle is not in the lowest notch, try moving it to there and see if it does better. Do this in an area where you can find anyting that might come out when you remove the carb screwed top. It should stay toogether but better safe than sorry. To access the main jet you will still have to get the bowl off, the gasket must be just stuck. If you can't get bowl off try spraying some cleaner up into carb through the drain plug. It can't get to anything that need cleaning through the bolt holes. Don't let it sit long though as the needle or seat is probably some type of rubber or neoprene and might be damaged by the cleaner full strength. bg

 

[CumminsAholic]

Yup, probably lack o fuel. Carb bowl should come off when you take the 4 screws out. When you took the nut off the bottom was it green or varnished (sticky) inside? It probably isn't the fuel pump because it runs on choke. Get the bowl off and take out the main jet and pilot jet and clean them. If they're really bad you may have to use a small piece of stiff wire to clean them or get new ones, they're not that expensive.

Corey

 

[TowPro]

If the carb is like a motorcycle carb the main jet is all the way at the bottom of the bowl. When you put them away "wet" (fuel in the carb) the fuel starts to break down and go bad. The lowest part in the carb is what gets the most crap on it, which is the main jet.

I run Sta-Bul in every gas engine I own all year to prevent this problem

 

[TRAMPLINEMAN]

Do a compression test, should be around 100 psi. Could be bad rings. Also, while the machine is running, spray carb cleaner or starting fluid around the head and base gaskets. If the motor revs up, you've got a blown gasket. Spray the fluid around the crank seals as well, might have a bad seal. I think you might have more than just jetting problems.

 

[IC Smoke]

Thanks for the input guys!!!



I took the carbs to our sister shop (mid-amercia motors) and they tore into them, Come to find out the jets were almost completely plugged!!!! the pervious owner left air in the tank (not full tank) and no sta-bil either so the jets were clogged with crud! I pulled the manifold (due to a leak) and looked in from the ports and both cylinders looked fine (no scratches, burn marks etc... ) from what i could see. Im in the process of new fuel lines, tank drain, etc... .





Thanks!!!!



Ian

 

[TRAMPLINEMAN]

Cool, I hope that's the extent of your problems. The early 90's Arctic Cats are know for blowing gaskets and burning down. Good luck.