Hi all,
I have a quick question for everyone. I just bought a 2005 yamaha raptor 350, things mint.
Ill explain first the problem and then give some background info. So the problem is when the quad is warm or cold and i give it a little bit of throttle it seems to almost like skip and it sounds like loud woosh of air from underneath me or coming out of the front of the quad, which i think its shooting down the muffler pipe right out of the machine.
So the background is that when i have the choke on it runs fine and when i give it a little more than a quarter throttle it runs fine also.
The reason its bothering me is when i ride it down the street after i shift and hit the gas it hesitates and thats kind of annoying.

So i talked to someone and they said use higher octane, im using regular gas now which i think is 86 or 87 and then someone said it could be the jets, now the guy i just bought it from said he just redid the carb because it sat a while so im thinking it possible could be a clogged jet and thats why they its on choke or full throttle it dosent happen because theres enough fuel going through to make it run fine.
So thats eveything. I hope you guys can help. Thank you very much

 

It sounds like a clogged jet to me. As far as octane, if this engine doesn't have a high compression piston installed 87 octane is all that is required. Higher octane only helps with detenation from high compression, it actually burns slower with higher octane

 

Yeah I don't think he got all the gum out of the carb. The main things to clean are the main jet, the pilot jet, the fuel bowl, and the float valve.

 

Pull the jets and make sure they aren't clogged, mostly the pilot. It is possible that even with a good cleaning some crud was either left in the bowl or came from further upstream and clogged the pilot. Installing a fuel filter is a good idea if it doesn't already have one.