Engine suddenly locked up

[gamblesci22]

Just started the engine and it ran for a few seconds. There was a rattling sound and then it suddenly locked up. Removed the spark plug & there was smoke coming out from the chamber. What’s going on & what should I do now?

 

[GW's Motorized]

The first thing I would do is check under the clutch arm cover for chain jam.

 

[Chainlube]

The first thing I would do is check under the clutxh arm cover for chain jam.

What is that? I see signs like that on native lands around here.

 

[ImpulseRocket]

What’s going on & what should I do now?

Only you can answer the question. As GW suggested, take off the sprocket cover, if everything looks ok there, magneto and clutch covers and inspect. If nothing looks wrong there then something likely happened in the cylinder. Remove the head and see what you find. Once the issue has been located we can go from there.

 

[gamblesci22]

Only you can answer the question. As GW suggested, take off the sprocket cover, if everything looks ok there, magneto and clutch covers and inspect. If nothing looks wrong there then something likely happened in the cylinder. Remove the head and see what you find. Once the issue has been located we can go from there.

Checked the magneto, turns out the nut fell off. Now it’s unseized

 

[GW's Motorized]

What is that? I see signs like that on native lands around here.

Lol. I fixed it. I try to reply between classes, but I don't really have time to spell check lol

 

[DAMIEN1307]

but I don't really have time to spell check lol

NOOOOO, REALLY???...lol...lol...I would have never guessed...lol...lol.

 

[gearhead437]

Hey Gamblesci22! My Pk80 from CM had less than 10 miles on it when one day I began the pedal start and the engine cranked VERY sporadically. Turns out that the clutch assembly retaining nut was finger tight and had started to spin! I cleaned all fastener surfaces with Acetone, reformed the star washer, applied blue Locktite and carefully torqued the nut to felt maximum force. I then let it cure for a few days. Thankfully, it's been okay since then, but I never saw this on my 49cc Grubbee-Gearhead437

 

[Whitewill1412]

Hey Gamblesci22! My Pk80 from CM had less than 10 miles on it when one day I began the pedal start and the engine cranked VERY sporadically. Turns out that the clutch assembly retaining nut was finger tight and had started to spin! I cleaned all fastener surfaces with Acetone, reformed the star washer, applied blue Locktite and carefully torqued the nut to felt maximum force. I then let it cure for a few days. Thankfully, it's been okay since then, but I never saw this on my 49cc Grubbee-Gearhead437

Always make sure everything is tight before you run your engine