Ski-Doo / Engine Question...

WakeUp · 12-29-2008, 06:28 AM

2 weeks ago my 2001 380 Formula was running great. Yesterday I started it and only 1 of 2 cylinders was firing. I checked for spark, and both plugs were getting spark. In changing the plugs yesterday I did notice the cylinder not firing was dry - no gas getting to the cylinder.

Could the problem be that the fuel pump is 1/2 bad? (there is no scent of gas, so I'll rule out cracked/broken lines to and from fuel pump)

What other things should I look at before sending off to the Ski-Doo hospital?

Any and all ideas are appreciated.

WINNOCTURN · 12-29-2008, 08:22 AM

WakeUp,

It could be a number of "SIMPLE" things. It could be some debris blocking the Needle and seat, a stuck "FLOAT". As for the fuel pump, if it easy to get at try swapping the lines at the pump, fire the engine and see if the problem now occurs in the other cylinder. If no change try to check for fuel in the carb bowl. If it is dry it could be "dirt" or a stuck Float? If the Float is stuck try tapping the fuel bowl several times with a metal object.

Good luck.

WINNOCTURN

ITD · 12-29-2008, 09:00 AM

Quote:

Originally Posted by WINNOCTURN

WakeUp,

It could be a number of "SIMPLE" things. It could be some debris blocking the Needle and seat, a stuck "FLOAT". As for the fuel pump, if it easy to get at try swapping the lines at the pump, fire the engine and see if the problem now occurs in the other cylinder. If no change try to check for fuel in the carb bowl. If it is dry it could be "dirt" or a stuck Float? If the Float is stuck try tapping the fuel bowl several times with a metal object.

Good luck.

WINNOCTURN

I'd check the jets also, unscrew the offending side and blast carb cleaner through it. Could be gummed up, did you stabilize gas over the summer? If not gas could have turned to varnish.

trfour · 12-29-2008, 12:56 PM

WakeUp, sounds as though water, or moisture has gotten into the fuel system. Even if you use stabilizer in the fuel in the off season, if you don't keep the fuel tank topped off, it will rain condensation inside of your fuel tank with the heat and cold temps over time. It only takes less than a very small drop of moisture to totally block a jet, and not allow any fuel to pass through it. I would strongly suggest cleaning the entire fuel system, as if you trail ride without a moisture free fuel system, it can lean out the fuel mixture and burn pistons in a heart beat! Also, I would do a vacume check on each cylinder, as a worn or blown crankshaft seal would also keep the proper amount of fuel from getting into the cylinder.

Good Luck.
T.

chipj29 · 01-05-2009, 08:33 AM

Had the exact same problem with a Ski Doo 550 fan just last week. We took the carbs apart and found the float needle to be sticking. A squirt of WD-40 solved the problem in no time. We did do a thorough cleaning of the carbs too, but the sticking needle was the problem.

12-29-2008, 06:28 AM	#1
WakeUp Senior Member Join Date: Apr 2004 Posts: 83 Thanks: 0 Thanked 4 Times in 4 Posts	Ski-Doo / Engine Question... 2 weeks ago my 2001 380 Formula was running great. Yesterday I started it and only 1 of 2 cylinders was firing. I checked for spark, and both plugs were getting spark. In changing the plugs yesterday I did notice the cylinder not firing was dry - no gas getting to the cylinder. Could the problem be that the fuel pump is 1/2 bad? (there is no scent of gas, so I'll rule out cracked/broken lines to and from fuel pump) What other things should I look at before sending off to the Ski-Doo hospital? Any and all ideas are appreciated.

12-29-2008, 08:22 AM	#2
WINNOCTURN Deceased Member Join Date: Dec 2004 Location: Moultonboro Posts: 849 Thanks: 350 Thanked 351 Times in 193 Posts	Go for the Simple Things? WakeUp, It could be a number of "SIMPLE" things. It could be some debris blocking the Needle and seat, a stuck "FLOAT". As for the fuel pump, if it easy to get at try swapping the lines at the pump, fire the engine and see if the problem now occurs in the other cylinder. If no change try to check for fuel in the carb bowl. If it is dry it could be "dirt" or a stuck Float? If the Float is stuck try tapping the fuel bowl several times with a metal object. Good luck. WINNOCTURN

12-29-2008, 12:56 PM	#4
trfour Senior Member Join Date: Nov 2002 Location: The Lakes, Central NH. and Dallas/Fort Worth TX. Posts: 3,694 Blog Entries: 3 Thanks: 3,069 Thanked 472 Times in 236 Posts	WakeUp, sounds as though water, or moisture has gotten into the fuel system. Even if you use stabilizer in the fuel in the off season, if you don't keep the fuel tank topped off, it will rain condensation inside of your fuel tank with the heat and cold temps over time. It only takes less than a very small drop of moisture to totally block a jet, and not allow any fuel to pass through it. I would strongly suggest cleaning the entire fuel system, as if you trail ride without a moisture free fuel system, it can lean out the fuel mixture and burn pistons in a heart beat! Also, I would do a vacume check on each cylinder, as a worn or blown crankshaft seal would also keep the proper amount of fuel from getting into the cylinder. Good Luck. T. __________________ *trfour* Always Remember, The Best Safety Device In The Boat, or on a PWC Snowmobile etc., Is YOU! Safe sledding tips and much more; http://www.snowmobile.org/snowmobiling-safety.html

01-05-2009, 08:33 AM	#5
chipj29 Senior Member Join Date: Apr 2004 Location: Bow Posts: 1,874 Thanks: 521 Thanked 308 Times in 162 Posts	Had the exact same problem with a Ski Doo 550 fan just last week. We took the carbs apart and found the float needle to be sticking. A squirt of WD-40 solved the problem in no time. We did do a thorough cleaning of the carbs too, but the sticking needle was the problem. __________________ Getting ready for winter!