It's sudden, cuts out for about a second, or less. I suspected fire over fuel, because it quits, then resumes again, suddenly. It doesn't slow down, it's like turning it off for a second, then back on. Makes for a jerky ride just when I want speed.
But wait! I found that I could make it cut out predictably by going at less than full throttle, then goosing it to full throttle. Immediately after gunning it, it will cut out for a half second or so. Then it's back to normal.
Is this the overfilled gas tank issue? The seller, a friend, seems to think so, and said he had overfilled the gas tank more than once. If so, how to fix please?
(I will test for vapor lock tomorrow by loosening the gas tank cap - is this behavior consistent with vapor lock? Not sure what that does.)
At full throttle, going at an indicated 50 mph, it will keep cutting out intermittently. Very rarely under 50 mph. My initial instinct was that it vibrates an electrical connection loose (occasionally) at that speed, because of vibrations and stuff.
But wait! If I back off the throttle a bit, it will run smooth, still at about 50. Implying fuel, more than fire, it seems.
I'm pretty sure that if it was smooth at full throttle, I'd get a faster top speed.
Not in California, so any modification tips for more power would also be appreciated. A converter I could remove or something?
Cheers!
Scott
PS - former owner is a motorcycle / scooter guy, who knows about cleaning air filters, probably used Seafoam, etc. Someone he talked to suggested the emissions canister / overfilling gas tank thing. Could not find "emissions canister" in the 186 page PDF service manual.