"Matt, 4 strokes can be tricky
"Matt, 4 strokes can be tricky to figure out when they are not right in front of you. And even then half the times it's a guess for most of the guys on here who bend wrenches on 2 strokes.
90% of them need to be plugged into a computer to even diagnose the simplist of problems. Why? because the on-board computer will compensate to some extent for a bad components - traditional troubleshoot where you disconnect/unhook something to see if it's the problem will be ignored by the computer and instead it will tell itself "what it wants to hear".
I have read a bit through the factory manual and see that your particular model does not have a bunch of sensors such as found on later models - at least that reduces the probable causes.
Having said that the only thing that I can see which may be causing your issue (and I don't work on 4 strokes so you have to take it with a grain) is a possible vaccum imbalance.
The service manual gives a multi-page, very detailed set of instructions as to how to balance the vaccum and adjust the carbs (required after fiddling with the vaccum).
My suggestion would be to obtain a factory service manual (ya 80 bucks or so, but Seloc's etc won't do in this case) and fiddle with it yourself. The cost of the manual is still about 20 bucks less than a shop would charge to take the cover off and have a look...."
