When you replaced the spark plug, what plug gap, plug type, and method did you use?

If the spark plug wasn't gapped properly or if the tip was damaged it could cause some issues. Really with the bike being hard to start when hot, it still kinda sounds like a fuel setting. Another thing that worries me is you said the. 018 drillbit went straight through your starter/enriched jet... I've not drilled mine but is it possible it was drilled to wide? Did it easily fall through or just barely fit?

Also, it only starts with the filter off because its saturated with the oil and can't breathe. There's got to be a reason that your getting oil in your airbox, especially to that extent.

Don't worry, you'll get it worked out soon, then it'll be a thing of the past

Paul

 

I replaced the spark plug with a NGK CR8E, It was already pre-gapped as verified with my feeler gauge. The drill bit barely fit, it wasn't like a super huge hole, sorry for the confusion. I cleaned out the air filter last night and refilled the motor oil, which I'm pretty sure that the oil being overfilled was the issue of it spitting out of the airbox. I'm thinking about replacing the pilot jet with a new #35, because obviously that has got to be my issue with starting.

 

Mine's been getting hard to start so I checked the valve clearance today, sure enough they were out of spec,but oddly still weren't tight. I swapped to some smaller shims and it fired right off. It even sounds stronger. I can understand how if the valve wears to zero lash it could affect compression. My worst was the right side exhaust down to only .002" it seems to me this would just add a little lift.Anyway, I bet that's your problem.
good luck
marc

 

Thanks for the heads up. How many miles does your bike have on it?, because mine only has 105.

 

105 miles would be odd for tight valves, but stranger things have happened. Worth a check with all the frustration you're having with it. If nothing else other than to rule it out.

 

That low a mileage makes me think that something is REALLY stuck in a tiny passage in the carb. I know the carb has been cleaned several times but .....

Has the carb been soaked for a few days* in a potent cleaner? You know the kind; you take the lid off and you can hardly breathe, your eyes start to water and your throat feels like it's on fire. Maybe those aren't around anymore.

*read the label, a few days might be too long and there will be nothing left but a lump of "metal"

+1 on "check the valves to rule that out".

 

I'll check them over for peace of mind if nothing else, It's not that big of a deal just to check anyways. I appreciate the help gentlemen, I'll also be getting in that new pilot jet within a few days I hope. I'll make sure to post when or if I figure this out to help others in the future.

 

Finally had enough time to work on this again and replaced the pilot jet, but still the same problem. I measured the clearance (intake=.10mm to .19mm) on all 4 valves and one of the intake valves will clear .10mm, but will not clear .13mm to .19mm. The other intake valve will clear all of the above, with the .19mm coming to slight resistance, just like it should. So my question is, should that .10mm valve be shimmed, and can that one valve make that much of a dramatic starting difference?

 

I've now got a shim on order, caliper said the old one was a 2.95, and there was also a mark on the shim that said that as well, so I've got a 2.90 on the way. We'll see what happens.

 

UPDATE: Replaced the valve shim, so now all of the valves are well within spec. Reassembled everything together, and still having the same issue. The bike will start every once in a while with the choke on and the throttle cranked a little bit. Once the bike is running, it will then die and be next to impossible to restart. This bike can be bump started. So to clarify, the valves are a definite check off the list. I'm thinking a possible compression issue?