2005 Yamaha Raptor - Wont Start Consistantly

[sglass]

My 2005 raptor 350 will not start consistantly, and even harder to start when its warm. When it does start it purrs like a kitten. When it does start it starts right away, very seldomly do you have to crank it over for a few seconds to get it to start. Ive confirmed spark,new spark plug, had my carb gone through and float adjusted and had the valves adjusted with still no consistancy. Only other guess is CDI,Starter relay..... Any help would be greatly appriciated.

[pete59edsel]

Shootin from the hip I'd lean towards the coil....thing that tells me that is the "when it gets warm" part. Keep us posted and good luck!!

[GREENIE]

when it won t start is it turning over or just clicking.

[sglass]

Yes it always turns over. And everytime ive checked 5-6 times there is always good spark.

Edited May 5, 2012 by sglass

[sglass]

If the starter relay was failing would it even crank over?

[GREENIE]

you might have a bad batch of gas, i just had issues with my step sons raptor 350. it would run then wouldn t start. cleaned the tank and carb out . then it would run a couple days then not start. finally got fed up and took it to a shop and it did the same thing for him . finally he figured out that the gas was bad. if the gas sits too long the gas and ethalol separates and sometimes you might end up with all ethanol. try putting new gas in it and make sure you put the ethanol treatment in it. its about $20 a bottle but it worth it. i havn t had a problem with it since.

[oxidized_black]

Shootin from the hip I'd lean towards the coil....thing that tells me that is the "when it gets warm" part. Keep us posted and good luck!!

i think you nailed it pete59edsel

[sglass]

Tried everything you all suggested and no leads : ( Even when warm I have spark, but it lead me to wonder. There is spark but how do I know if its enough of a spark. How can I confirm there is enough spark to create ignition?

[sglass]

Would low compression explain my not starting when warmed up?

[marioweldinginc]

Tried everything you all suggested and no leads : ( Even when warm I have spark, but it lead me to wonder. There is spark but how do I know if its enough of a spark. How can I confirm there is enough spark to create ignition?

I know they have spark gap testers for regular autos but i dont see why it cant work on atvs. They usually have them at autoparts stores. It has a screw on one side and you adjust the gap to a preset level according to the instructions. If it wont fire then the spark is weak.

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[sglass]

Think thats it. I have 90psi comming out of the cylinder when its cold and 85 when its warmed up. So guess next step is a top end. Hope I can just do rings.

[myquadrepair]

I would do a compression check to rule it out.

[sglass]

I did, I had 90 psi when cold and only 85 psi when warmed up.