So I purchased my 07 raptor 350 about a month ago, and it’s ran great til now. I came back from a rather long ride, (so it was quite hot) and when I pulled the clutch in on my way down the driveway it cut out. It took forever to restart, and when it did, it kept dying. So I let it completely cool. When I tried to start it later, it wouldn’t start. Checked and I wasn’t getting spark. But when I give it gas, my tach slowly goes up and then it starts. Once it starts, it won’t idle until it’s fully warmed up, and sometimes it even dies when I’m holding it at around 2200 rpm. But as soon as it’s warm, runs like a dream. Ideas? Please help I’m very confused

 

Were you actually checking for a real spark with the plug laid on the head? If you are getting a spark when you first try from cold, could be compression, Yams are prone to valve clearances closing up and they then refuse to start from cold, once warm they must get a bit of clearance, so run OK. Other possibility is a partly blocked jet, so runs weak, not that noticeable hot but bad to start cold. If you are not getting a spark, could be anything electrical, change the plug and check again, but may be stator, ignition coil or CDI so test them out when the fault is on.

 

When I put the plug on the head, I get nothing unless I hold the throttle. Then spark becomes more frequent. What I don’t get is why something electrical would work hot but not cold, and why it only works cold if you give it gas. I’m going to one at a time start ordering up those parts. I don’t know how to change a stator, though. Sure does sound like valve clearance doesn’t it? But it went from running perfect to this in one ride, so I don’t know if that’s possible.

 

I think what I’ll do is start off with adjusting the valves, cause it needs it anyways. How hard is it to do? Could you give a short description?

 

I talked to a friend who is a mechanic. He says he’s beat by the spark thing but everything else sounds like tight valves. I don’t necessarily want to send it to the shop, but if it’s gonna be hard to adjust I will.

 

Can't say for certain but I would bet the Raptor is the same as the other 350 Yams as far as valve adjustment goes. There will be lots of U tube videos on how to adjust them. Valve covers off, cam side cover off. Move engine round until cam timing mark is in the TDC position. Set both valve clearances,

Can't weigh up why you would be opening throttle with plug out, it won't make a blind bit of difference to the spark. Unless it has a throttle position sensor, in which case, I guess that could be what is faulty.

 

Thank you. I’ll see if I can set them on my own. I don’t know what’s going on with spark still, I’ll have to experiment. It doesn’t look like it has spark when it’s dead cold. But when I hold the throttle, the tach climbs, 10,60,200,270, and it starts. It needs a valve adjustment anyway, I’ll just start with that. Thank you!