Z 370 too much smoke . - Snowmobile Forum: Your #1 Snowmobile Forum

COOKSTER · 09-26-2009, 06:06 PM

I just bought a 2000 Z370 that was last used in 2002 and has only 1200 (miles/kms??).
Before even trying to start it I drained out the old gas and replaced with new and I also removed the carb and cleaned it. After several pulls the engine fired but was smoking excessively and I was unable to rev the motor, it would just bog as soon as I touched the throttle. After running at idle for about a minute the motor just died as if it had run out of gas.
When trying to restart after it died, the compression was super high and I could hardly pull it over.
I was thinking that maybe the excessive smoke was from the motor being fogged for storage but I dont know for sure. I have also heard that some people hold the oil supply lever wide open for a few seconds while the motor is running to dump in extra oil when putting the sled into storage.
Sorry for my long winded story but I wanted to include as many potentially relevant points as possible.
Any ideas?

throttlejunkie · 09-26-2009, 08:06 PM

just a thought but I bought a 91 prowler that had been sitting for a awhile and had the same problem. Turned out that the oil tank emptied into the motor while it sat and the motor hydro-locked. All I did was take the plugs out and pulled it over A BUNCH of times to pump some of it out. It made a mess but worked. It still smoked real bad for a few minutes after I started it but it cleared up and ran great. Hope that helps.

COOKSTER · 09-27-2009, 07:27 AM

Thanks for the reply.
That exact thought had already crossed my mind but I wasnt sure if it was possible. Now that I know it can happen I will check it out. Does anyone know if these motors have drain plugs at the bottom of the crank case?
As another possible cause, I was planning on checking the fuel pump today on the theory that if its not providing enough fuel...
A) The motor will not be able to run at higher speed .
B) The motor would eventially die due to lack of fuel.
C) Less fuel entering to motor would increase the ratio of oil to fuel causing excessive smoke.
My sled currently exhibits all of these conditions.

**kccats** · 09-27-2009, 10:26 AM

Yes they have plugs, one is a nipple with the pulse line on it to the fuel pump!
Look at your plugs too, bet they are fould out!

**RJ Gleason** · 09-27-2009, 12:57 PM

Did you soak clean the carbs or use spray cleaner?

COOKSTER · 09-27-2009, 07:13 PM

Well I got it fixed.
The crank case was full of gas. I pulled out the spark plugs yanked it over for about a minute till no more gas was spitting out then re-installed plugs.
Took a lot of pulling but it finally started and this time it continued to run.
After about 2 minutes at idle the thing was running perfectly so I shut it off and tried a re-start, first pull and away it went. Left it for 3 hours and tried another re-start and once again, 1 pull and off it went. I plan on putting new plugs in but the way it's running now its not really necessary.
I didnt soak the carb, I used the aerosol cleaner and compressed air.
In 20 years of working on old sleds I have never had to soak a Mikuni, maybe Im just lucky??

**RJ Gleason** · 09-28-2009, 08:59 AM

Yep, you have been, soak is still the best way to clean them as it gets all the gunk out.

COOKSTER · 10-12-2009, 08:31 PM

Quote:

Originally Posted by RJ Gleason

Yep, you have been, soak is still the best way to clean them as it gets all the gunk out.

Thanks for the advice RJ. I have 2 other sleds besides the Z 370 (90 Exciter and 90 Eltigre EXT 530) so I decided to invest in the soak cleaner. $72 bucks a gallon and now Im in business. I took the carb back off of the Z and soaked it overnight. I also removed the fuel pump and and found it was full of oil from the pulse hose so I rebuilt it then pulled the motor out to make sure I got all the old gas and oil out of the crank case. Sandblasted the exhaust since I had it off and now it runs like new. Buying a battery and chain oil this week and it's ready to ride!
Thanks to all.

phishook · 10-12-2009, 09:28 PM

Quote:

Originally Posted by COOKSTER

Thanks for the advice RJ. I have 2 other sleds besides the Z 370 (90 Exciter and 90 Eltigre EXT 530) so I decided to invest in the soak cleaner. $72 bucks a gallon and now Im in business. I took the carb back off of the Z and soaked it overnight. I also removed the fuel pump and and found it was full of oil from the pulse hose so I rebuilt it then pulled the motor out to make sure I got all the old gas and oil out of the crank case. Sandblasted the exhaust since I had it off and now it runs like new. Buying a battery and chain oil this week and it's ready to ride!
Thanks to all.

Check your fuel pump. My guess is it's bad, or it's hooked up backwards (allowing the tank to drain into the crank)