1978 John Deere 440

liquifireZach · Post by **liquifireZach** » Wed Jan 19, 2011 4:51 pm

I have a 1978 John Deere snowmobile and it wont start. There is gas that is coming out of the exhaust pipe and spark plugs are flooded.
What could be the problem?
Thanks Zach

crazzygunner · Post by **crazzygunner** » Wed Jan 19, 2011 5:14 pm

It sounds like you are geting gas so I would check spark because it sounds like the gas is not geting ignited and going through to the exaust so check for spark and if no spark make sure that the kill switch is not on or bad because I have had this happen a few times also was it running recently if it was then it could be something simple like a kill switch as long as you got gas spark and compeson it should be a go good luck.
Evan

Invader440 · Post by **Invader440** » Wed Jan 19, 2011 7:18 pm

I'd check and make sure the needle in the carb is seating correctly.

Post by **Matt** » Wed Jan 19, 2011 9:47 pm

Here is a complete troubleshooting guide:
http://www.jdsleds.com/tech/troubleshooting.html

JDT · Post by **JDT** » Wed Jan 19, 2011 10:16 pm

If you have gas running out the exhaust, it is flooded so bad that spark will not ignite it.

Unhook the fuel line, remove the spark plugs and pull it over until all the gas is out of the crankcase.

Then confirm spark , check carbs and recheck neddle and seat plus set floats as suggested.

Then hook up fuel again and try to start it.

An totally flooded case can have 2 or 3 cups of gas in it so be carefull.

A backfire with a bellypan full of gas can have you looking for a new garage.

JDT · Post by **JDT** » Wed Jan 19, 2011 10:18 pm

Did you test compresssion?

O'Deere · Post by **O'Deere** » Wed Jan 19, 2011 11:51 pm

Be sure you have a 6f27 jet needle in there. Too high of a fuel level in the bowl could be a factor.

liquifireZach · Post by **liquifireZach** » Thu Jan 20, 2011 9:03 am

I am getting spark and i just cleaned the carb. It first started acting up when hot and then i took of carbs and i noticed that my Idle screw was missing so i took another one out of another mikuni carb and i made sure it was the right size and all then i replaced the spark plugs and fuel filter now I am were I am at.
Is there an easier way to drain the gas out of chain case so I dont blow my sled up from a back fire.

liquifireZach · Post by **liquifireZach** » Thu Jan 20, 2011 9:19 am

How many turns out does the idle screw have to be out?And also the fuel one?

liquifireZach · Post by **liquifireZach** » Thu Jan 20, 2011 4:13 pm

How much is compression supossed to be in both cylinders?

O'Deere · Post by **O'Deere** » Fri Jan 21, 2011 1:07 pm

Specs will be found in the repair manual. Another recent thread on here will refer you to a site to download the manual for free.
"Started acting up" you hadn't previously mentioned that, you only previously stated symptoms of flooding. Please specify what are all the problems.
A overfilling carb bowl is what I would guess is causing your problem. Needle & seat would be the likely cause for this.

1978 John Deere 440

1978 John Deere 440

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Re: 1978 John Deere 440

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