You might want to install carb kit and if you want a bit of pep get the Dynojet kit and set it on third notch and use #126 main.

Good Luck

 

I did the block off deal and with it blocked off mine would BARELY start and when it did it really didn't want to run at all. I won't say that the choke hurt much but it surely didn't help any either. I tried it with the air filter off and again with a piece of duct tape covering several different portions of the airbox-to-carb hole and the best I could get was about 22mph down a 1/2 mile road. My plugs looked the same too, like someone grew coal soot all over the whole end of it. I'll pull the carb again this weekend and see if there are clip grooves in the needle(I can't remember). Otherwise I'm pretty much down to a carb kit and/or a cdi.... I noticed quadfussion is having what seems to me the exact same issues after he put a carb kit in.

 

So you have fuel, air, and what you believe is good spark. I really think you should test your compression just to rule that out. Might have a bent valve or some other issue. Compression tester at HF is pretty cheap.

 

I'll get him to get a compression tester set from hf because the set I have doesn't have an adapter for that small of a spark plug hole. I'll report back when I get it tested. There's no internal compression release on this motor like the sport 400's is there?

 

I don't know about the compression release. I would say no. Per the service manual, the standard compression should be 142psi. They recommend doing it after a valve adjustment, with the engine warmed up, and WOT.

 

What do I need to remove from the top end to check the timing and valve adjustment? I see the little cap screw for the bottom timing mark but I have no idea what all I need to do to get to the top or what the specs are on either.

 

This might help with lots of maintenance issues.
I have the service and repair manual as a download around 55mgbs.
This site seem to have the same, check it out and
Good Luck
REPAIR MANUAL DOWNLOADS

Norm

 

Tank will need to come off, left side covers, take the sight hole plug out, take the spark plug out, pull gently on the pull starter until the timing mark lines up with the arrow on the case. That'll get you to TDC. Will want to make sure it is on the compression stroke. If its on the exhaust stroke, there will be no gap and I don't believe you'll be able to get your feeler in there.

I also have the manual on disc in case you need it. Pretty cheap on ebay, under $10 on cd-rom.

Valve clearance (when cold)
IN: 0.05 – 0.10 mm (0.002 – 0.004 in)
EX: 0.22 – 0.27 mm (0.009 – 0.011 in)

 

Im assuming there is no possibility that this could be another case of a bad Magneto?

I know the Eiger's had Magneto issues where the magnets would come unglued and slide around in the basket. Most of the time it causes them to wind up with no spark, but it may be possible that they arent all loose yet allowing it to run ok at low RPM? Although it doesent seem like it would run good at low rpm and then change at higher RPM.

Also, I know you checked it, but be SURE your voltage regulator is good. My Suzuki Quadrunner 250 all of a sudden one day decided it wouldnt rev. Sounded just like a rev limiter. It was the voltage regulator gone bad allowing it to go into limp mode which only allowed very limited RPM.

 

what is the testing procedure for the voltage regulator? i.e. which wire should be what for a working one? I know while running the battery reads around 14.5 or so volts. I'll pull the cover off this weekend and check for broken/loose magnets. I've read about this happening on the 400 eiger motor in arctic cats and suzukis...