my top end blew :( help my find out why pls

GoldenMotor.com

moosinatrix

New Member
Sep 2, 2009
124
0
0
Houston, TX
ok so i was out riding around, i was chaasingmy brother through the neighborhood as he left to the store, i was flying pinned out when my bike started making some nasty metal on metal pinking, tinking clanking all that jazz.

i tore down the topend and sow quite a bit of scoring on the cylinder walls and piston as well as some knarly chew marks on the head and top of the piston.

posting pics in a sec.
 

moosinatrix

New Member
Sep 2, 2009
124
0
0
Houston, TX
also since im replacing the top end anyway, might as well upgrade. any suggestions to top end kits that boost performance with minimal modification??
 

Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
11,837
252
63
up north now
Could have been the ring alignment pin, or as stated above (if you have them) a needle bearing got loose in there.

Or just chinese QC gone awry.
 

Greg58

Well-Known Member
May 1, 2011
5,353
2,575
113
65
Newnan,Georgia
You need to know who made the engine, there are different wrist pin locations. I have a grubee and a bgf and the pistons and cylinders are not the same. I would measure the distance from the pin to the top of the piston and post it here, someone might be able to help.
 
Last edited:

Greg58

Well-Known Member
May 1, 2011
5,353
2,575
113
65
Newnan,Georgia
You need to check the connecting rod for damage, a bearing that bad had to scar or distort the rod. It may cost less to buy a engine.
 

Chubbz McNasty

New Member
Sep 27, 2012
5
0
0
Tucson
She's seen better day's I'm sure... Just my opinion but If I were you I'd go all out and buy a whole new motor. Why put brand new parts on top of REALLY old ones? That's what I would do anyway.
 

moosinatrix

New Member
Sep 2, 2009
124
0
0
Houston, TX
well this kit has virtually no hours on it cept for what i put on it recently. but i am most likely gonna buy a new kit and have lots of spare parts laying around.