Jump to content
Sign in to follow this  

My piston is Toast!

Recommended Posts

I have stripped down my 07 motor to replace the piston and it seems well overdue ( I have just bought the bike), There seems to be heavy carbon build up in the head, but mostly at the front (see pics) is this just due to the piston being worn or something else? Also the cylinder also seems to have some engraving and I am not sure if this is std (see pics) any input would be great.

[/img]01032010494.jpg01032010497.jpg01032010503.jpg

Edited by hallam76
changed photo

Share this post


Link to post
Share on other sites

I've never heard of a cylinder being engraved like that... But it isn't going to hurt you there on that tab either. I'd just ignore it. Yeah man thats a lot of blowby on your piston, your rings were toast. Carbon buildup can be caused by several things, probably in your case by the previous owner running too rich.

Share this post


Link to post
Share on other sites

Some engrave parts in case it gets stolen they have a way to prove it is theirs....but from the looks of where its engraved....thats one weird spot. I too would just ignore it.

Yeah, your rings were completely done. What does the cylinder wall look like?

Share this post


Link to post
Share on other sites

The cylinder wall is quite good, the horning marks are still there, but there are a couple of smallmarks but nothing to worry about. I was wondering if the cylinder had been ported at all, thats why it had the engraving, but all the transfere ports look std i.e. you can still see the casting marks??? I have found the head has been machined out, and it is engraved 'ENDURO' and 26cc. This is ok as I am going to use the bike for enduro anyway.

Share this post


Link to post
Share on other sites

your jetting is way off, the piston is overdue to be replaced now. should have been reringed many hours ago.

I would inspect the crank VERY carefully. Good chance it may need replaced also.

Clean everything up. This means remove the power valves from the head and clean them up also. Then measure the bore after a light hone and match up a piston.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:

Sign in to follow this  

×