LT80 top end rebuild woes
#1
LT80 top end rebuild woes
1987 lt80, my nephews. Wouldnt start due to low compression. I pulled the cylinder and piston and they were significantly scored up. Decided to buy a $50 ebay kit (cylinder, piston rings, etc). Came with two rings plus a thin spacer type ring. Couldn't get it together with the spacer ring, so I put it together without (just figured maybe it was an extra that comes with some of these universal kits). Started it up, ran two heat cycles and all was good. First run around the yard and it quit running due to low compression. Then tried changing plugs, ether, etc which required lots of use of the starter with no luck. Tore it back down and already had some grooves in the cylinder wall.
FWIW, this isn't my first go round with a 2 cylinder rebuild. I rebuilt my daughters lt80 10 yrs ago with a ebay kit, still runs fine with no issues. Have also rebuilt many full size dirt bike 2 & 4 stroke engines both complete rebuilds and top ends. Never had issues till now.
On with the story, Got another ebay kit (was provided for free from ebay seller of first one). This time after some more research figured out the proper orientation of the 3 rings and installed it. Also noted that the Chinese studs are garbage (threads stripped out) so I reinstalled the original studs. Put it all together and the battery wont spin the starter fast enough due to the increased compression. Tried the battery out of my full size dirt bike which has 130cca vs the lt80's 80cca battery. My battery wouldn't spin it fast enough either.
If my batteries are good & fully charged, could it be that I had previously overworked the starter and now its too week to spin fast? The charger was a new ebay starter that was installed during the initial rebuild.
Thinking my next step will be to pull the recoil starter off my daughters lt80 and put it on this one and see if I can get it started. Thinking maybe after a couple heat cycles/break-in maybe the starter will be able to turn it over?
Thoughts?
FWIW, this isn't my first go round with a 2 cylinder rebuild. I rebuilt my daughters lt80 10 yrs ago with a ebay kit, still runs fine with no issues. Have also rebuilt many full size dirt bike 2 & 4 stroke engines both complete rebuilds and top ends. Never had issues till now.
On with the story, Got another ebay kit (was provided for free from ebay seller of first one). This time after some more research figured out the proper orientation of the 3 rings and installed it. Also noted that the Chinese studs are garbage (threads stripped out) so I reinstalled the original studs. Put it all together and the battery wont spin the starter fast enough due to the increased compression. Tried the battery out of my full size dirt bike which has 130cca vs the lt80's 80cca battery. My battery wouldn't spin it fast enough either.
If my batteries are good & fully charged, could it be that I had previously overworked the starter and now its too week to spin fast? The charger was a new ebay starter that was installed during the initial rebuild.
Thinking my next step will be to pull the recoil starter off my daughters lt80 and put it on this one and see if I can get it started. Thinking maybe after a couple heat cycles/break-in maybe the starter will be able to turn it over?
Thoughts?
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