Whu? Scoot runs at 25mph, then spark plug pops out?!

[eisen011]

Okay. 84 Spree started again last night after replacing spark plug, oil pump, getting rid of 50cc oil in c.c., draining gas, oil, and cleaning carb. Everything I did was right out of the manual. Beauty! First engine I've ever fixed!

Ran it today and it was good. A bit smoky and bogged a bit on hills initially, but then again there was a lot of crud in there and I havent run it for 8 mo. Problems were working themselves out as I rode though.

But, after 10-12 miles of rolling hills at 20-25mph, I heard a "pop" and the Spree died. Took a peek and the coil cap, with spark plug attached, had popped off! Okay, so what does that mean? The plug was a little filthy too, but I wiped the oily crud off. After waiting a few minutes for it to cool, I screwed the plug back in by hand, attached the coil cap and it started right up and I ran it another 4+ miles home. We poured a capful of gas into the hole where the plug goes to get it going yesterday initially, and my friend installed the plug during the fixing session yesterday. Was that plug in too tight/loose? I'm sorry to say I never checked his work since he's an electrician!!!!

Any input is awesome. Dont want to wreck the Scoot now that it lives!
-k8

[se50]

Well, your problem could be that you are hand tightening the plug. Good way to mess up the threads in the plug hole, too, if it tears the last couple threads out when it comes out.

[PimpinSpree]

not to mention you will melt your piston down with a loose spark plug from having an air leak there. Bad news

[noiseguy]

Hand-threading is OK if it gets you home.

Torque the plug to spec (10 ft-lbs, as I recall, please check first in manual). If it come out again chances are you're missing the crush washer or something's wrong with the surface of the head. I'm betting you have no other issues.