RIP 80 cc engine

GoldenMotor.com

heretolearn

Member
Dec 12, 2011
43
0
6
Texas
I was riding my Schwinn clairmont 7 speed cruiser with 80 cc engine today when the engine seized as I was riding. I was hitting about 29 mph when I heard a snap crackle pop noise that followed by the engine bogging down real fast. I also noticed after I heard the noise I heard what sounded like something metal bouncing around the engine. I was able to pedal the bike home about a mile where I took off the clutch cover to see if anything was wrong. Everything looked normal and the clutch was working as usual only now when you engage the clutch the engine will no longer crank over. It does freewheel but not crank over with the clutch engaged, Locked is what it is. I took off the spark plug to look inside and the piston is at the bottom position with no hope of turning. I am looking for any input on this situation, :-||
 

fatdaddy

New Member
May 4, 2011
1,516
4
0
San Jose, Ca.
I was riding my Schwinn clairmont 7 speed cruiser with 80 cc engine today when the engine seized as I was riding. I was hitting about 29 mph when I heard a snap crackle pop noise that followed by the engine bogging down real fast. I also noticed after I heard the noise I heard what sounded like something metal bouncing around the engine. I was able to pedal the bike home about a mile where I took off the clutch cover to see if anything was wrong. Everything looked normal and the clutch was working as usual only now when you engage the clutch the engine will no longer crank over. It does freewheel but not crank over with the clutch engaged, Locked is what it is. I took off the spark plug to look inside and the piston is at the bottom position with no hope of turning. I am looking for any input on this situation, :-||
Sounds like the top end seized up. A PITA but not really that big a deal. Most of the time you just buy a new cylinder, piston, rings, wrist pin and bearing (Don't forget the gaskets) and slap it back together. Sometimes you can save the piston if it's not scored up.
THEN---- You REALLY gotta figure out why it seized so it don't happen again. Was yer mix right? One guy thought he could put straight gas in it "just untill he got home" a few blocks away. (didn't work, seized it.) And sometimes carp happens for no good reason except it's cheap china carp.
Al Fisherman has a great thread on the whole process of rebuilding. If you can't find it get back to me and I'll do a search for it.
fatdaddy.
 

maurtis

New Member
Dec 14, 2011
707
0
0
Kyle, TX
Wow, so sorry your motor seized up on you! Is this the same motor you have been having trouble with the past few months, with the clutch, woodruff key, and running better when you turn off the fuel?

If it is all on the same motor, so sorry for all the pain! Might be worth it to listen to Yank on this one and melt it down and replace with a different motor or do a complete and thorough rebuild, including all of the bearings.

BTW, would you mind following up on some of your older posts? It really sucks when you are using the search function to find info and run across a post that has the exact same scenario that you are seeing but then no resolution. Thanks!
 

maintenancenazi

New Member
Oct 22, 2011
157
0
0
Asheville
I was riding my Schwinn clairmont 7 speed cruiser with 80 cc engine today when the engine seized as I was riding. I was hitting about 29 mph when I heard a snap crackle pop noise that followed by the engine bogging down real fast. I also noticed after I heard the noise I heard what sounded like something metal bouncing around the engine. I was able to pedal the bike home about a mile where I took off the clutch cover to see if anything was wrong. Everything looked normal and the clutch was working as usual only now when you engage the clutch the engine will no longer crank over. It does freewheel but not crank over with the clutch engaged, Locked is what it is. I took off the spark plug to look inside and the piston is at the bottom position with no hope of turning. I am looking for any input on this situation, :-||
^^Sounds like the wrist pin needle bearing went bye bye... Sorry for your loss!
 

heretolearn

Member
Dec 12, 2011
43
0
6
Texas
Yes this particular build has already given me plus pain. This is the second motor I go through trying to get this bike running good. Its my brothers bike and he named it the rebel. I think some how the bike is living up to its name.