1978 Yamaha Exciter Wont Start - Snowmobile Forum: Your #1 Snowmobile Forum

mjk4348 · 12-10-2012, 01:02 PM

78 Exciter starts only with starting fluid or gas in the spark plug hole. Sled starts but dies immediately after it burns up whatever was sprayed into plug hole. Compression is 130/135. New fuel lines (Tygon) replaced on all fuel and oil lines. Black vacuum tubing line for the pulse line. New fuel filter. New spark plugs (NGK B9ES). Carb cleaned. Fuel pump rebuilt with new seals/gaskets. Fuel and oil visible in lines before and after oil pump and fuel pump. Sled will not stay running beyond five seconds. Somehow it appears that fuel is not getting to cylinders. Any ideas on what could be wrong? Thank you much.

ridegreen · 12-10-2012, 02:32 PM

You say that you can see fuel in the lines?

mjk4348 · 12-10-2012, 02:41 PM

Yes, can see the fuel in lines - there was an air bubble when we replaced fuel lines, but we blew air into the gas tank to blow out any bubble and have gas to and from the fuel pump and then to the carb. Thoughts? Thanks.

ridegreen · 12-10-2012, 02:45 PM

I would relook at the fuel pump, and reclean the carbs. If you have to spray or use gas to start it then it means the carbs isn't letting the gas flow threw and only runs on what you put in the cylinders.

mjk4348 · 12-10-2012, 02:59 PM

Thanks, will give it a try. After we replaced all fuel/oil lines, it started on second pull. We ran it for 10 -15 minutes, shut her down and have not been able to get it started again without gas or starting fluid in the plug holes. Thanks for your help. Will reclean the carbs.

79Exciter440 · 12-10-2012, 06:30 PM

I would definately clean the carb up real good, Possibly re-jet it. mine did the same thing except i also installed a new fuel filter as well. Hope it works out

99Polaris500 · 12-10-2012, 07:07 PM

Make sure you clean the carb bowl good, and check if the carb boots have any cracks.

Viktory2k1 · 12-10-2012, 10:23 PM

also double needle/seat

ridegreen · 12-10-2012, 10:26 PM

And check the primer as well

yammi1 · 12-16-2012, 09:15 PM

Pull your fuel line off the carb and crank the engine a few times. See what kind of pressure the pump has for spitting out fuel. Also make sure ur float is good and free. Also like viktory said, check the needle and make sure it's not stuck

yammi1 · 12-17-2012, 08:40 PM

Another test is to crank your engine a few pulls and carefully take your carb bowl off and see how much gas is in it. If its empty then you know the needle jet isn't working or the float is stuck closed.