If you haven't already, definately check out www.buggynews.com

Your post will be seen by FAR more people and you will get more responses.

That said, I would lean towards the valve guide or oil seals assuming
your rings are okay.



Have you seen a good GY6 service manual? TANK makes a great one (for
scooters, but it all applies) See the service manual section at
BuggyNews. Tank is the first, top thread in that forum section:

http://www.buggynews.com/viewforum.php?f=44

Do you have a decent filter on that buggy? Dirt shouldn't have gotten
past a well maintained, good filter system. Some of these karts
(older models mostly) come with a really crappy foam filter system
that lets a lot of dust and dirt in. Those engines end up with these
problems easily. Others have a better cannister and paper filter
system.... Even better, run a well oiled UNI with an outer wear
installed.

-Steve
Admin
BuggyNews.com



--- In ChineseORB@yahoogroups.com, "i_r_machinist" <i_r_machinist@...>
wrote:
>
> I have a Twister with a GY6 150cc motor. Took it to west Texas where
> it was rode like an army mule. Started smoking badly. Pulled the head.
> Cylinder was scored. Bought an oversized cylinder from Awesome
> Buggies. Top of new piston is 2.260", skirt is 2.283". New cylinder
> bore is 2.292".
> I'm running synthetic 10w-40 oil.
> My problem is that this thing smokes like an old Cheech and Chong
> movie.
> I have the motor apart right now and am about to order new valves and
> seals. Is my piston to cylinder bore clearance correct. It sure seems
> loose to me?
> Any help would be appreciated.
> Thanks
> i_r_
>
> PS. I want to buy another buggy but can't justify it with this one not
> running.
>