Cherrypicker
Member
I've got two of my Yamaha snowmobiles that for some reason act like the float bowl doesn't have fuel in it. I have a 90's Ovation which I have to initally crank almost 30 seconds or more before it lights. My 97 SX700 of course is manual start and it can take initally up to 20 pulls, not fun to fire up first time. Both sleds after the initial start up, fire up almost instantly after that first attempt. It is almost if the fuel has evaporated from the float bowls? In the past I've dribbled raw gas down in the air box, but caught a couple on fire, so I have resorted to using starting fluid, but is there something else that could be causing this?
on the ovation, it is kind of normal. i have an et410 t/r that i installed e start on because of this. i am the only owner of this sled since new. when it was new and i would let it sit longer than 2 weeks between running it, i always had to pull a plug and dump gas down a cyl to get it running. it has gotten a bit worse over the years and i have done a few things to it that helped a bit. replaced fuel pump to eliminate check valves/diaprham. did help but not a cure. the latest thing i did was to re seal the carb boot to the intake with permatex ultra grey as i was having an idle issue. straightened it out so idle is good again witch means in 10 years or so it will need a carb boot as just went through this all on a 78 et340 and that cured it on that sled.
you cold try the fix i was installing on the et340 when i discoverd the carb boot when the fuel lines to carb broke. i was putting a fuel shut off valve in the line from the tank to the pump as i noticed a large air bubble at the carb every time i went to start it. it would not be there after the sled ran. still testing my fix on it.
you cold try the fix i was installing on the et340 when i discoverd the carb boot when the fuel lines to carb broke. i was putting a fuel shut off valve in the line from the tank to the pump as i noticed a large air bubble at the carb every time i went to start it. it would not be there after the sled ran. still testing my fix on it.
NorthofSixty
Active member
I know that the check valve in the oil injection line can stick and allow two stroke oil to displace the gas in the float bowls after it sits for awhile. Mixture in the float bowls can be too oil rich to fire. The check valve stops fuel under pressure from back flowing into the oil tank but it also has a slight spring preload on the check ball to prevent oil from gravity feeding into the fuel pump when the sled is not running.