piston rings

[pbk]

hey

i was wondering if somone can help out and tell me if i need a engine rebuild front and rear. i have a 90cc its an 03 model and the rings seem to be worn on it cause its its not starting and low on compression, i got a quote ova the phone that it would need rebuilding fornt and rear for $450 cause if u just changed the piston rings the crank case would be under too much pressure and crack vertically and i wanted to check first if this guys ripping me of or not.

regards Liam

 

[FULL-ON]

I don't think you need a full rebuild but i'm not sure with a 4 stroke

 

[CHINGArider]

hey

i was wondering if somone can help out and tell me if i need a engine rebuild front and rear. i have a 90cc its an 03 model and the rings seem to be worn on it cause its its not starting and low on compression, i got a quote ova the phone that it would need rebuilding fornt and rear for $450 cause if u just changed the piston rings the crank case would be under too much pressure and crack vertically and i wanted to check first if this guys ripping me of or not.

regards Liam

Bloody dodgey barstards. Dont go back to them just pick up a new lifan off ebay

 

[NinetySix]

tru put about a teaspoon of motor oil into the spark plug hole (might have to lean the bike over on its side) and try the compression test again... if it gets a slightly higher reading then yeah it probably is rings, and assuming the bore is in good nick then a new set of rings is probably 20 bucks tops and about 1-2 hours of turning spanners, if you know what your doing..

if the oil doesnt help the compression reading at all then theres a good chance its a broken valve..


either way i wouldnt bother opening up an old 90cc when you could buy a brand new 140cc for $329 delivered to your door. might have to chuck in an extra 30-50 bucks for a 26mm carb too

 

[Hillz]

okat front & rear rebuild? the more common term is top & bottom rebuild.

& I would say you just need a top end rebuild like rings Or if it is a china bike the rings will be hard to find i which casr you will need a whole Piston Kit $105rrp & about 1 hour of labour to fit it.

 

[NinetySix]

just weigh up the options, would you prefer to just get it going or spend just a little bit more and get over 50% more capacity and a whole new motor