8 replies to this topic

[pop1wheelie]

Hi,

I noticed a post from a while ago about rebuilding a TLR top end. I'm doing a top end on a TLR 200 myself and found that Honda discontinued the piston. Apparently a XR 200 piston with a thicker base gasket could work? Does anybody know if this modification works?

Thanks!

Edited by pop1wheelie, 08 February 2009 - 05:38 PM.

[hondanut]

my xr200r barrel says 199cc whilst my tlr200 says 194cc, so there may be a difference, and i think the tlr piston is dished as well to give a lower compression, i know the at 185 piston is dished.

[pop1wheelie]

Hi,

Thank you for your response. If I'm not mistaken the only difference in pistons is the Compression Ratio? The XR CR is 10:1 while the TLR is 9:1. Would increasing the base gasket thickness work to reduce the CR enough to us the XR piston? Maybe I could reduce the dome of the XR piston to lower the CR? I now a lot of what I'm suggesting isn't very scientific but I'm kinda between a rock and hard place.

Thanks again!

[Andy M]

Increasing the base gaskets will help, this is a common mod on a 250 to soften the power. You will want some slack in the cam chain and don't run it too tight as this can damage the head. Are rings still available? I need some in my 200.

[pop1wheelie]

Hi,

Thanks for the info! I'm thinking about using two base gaskets it should add around .035" to the thickness before squish, have you ever tried this? Should I put a little silicone between the two gaskets? Does the cam chain require less than normal tension if so do you know why? I just got a set of standard rings and I'm sure there're available the part number is 13011-446-811 (same # as XR200).

Thanks!!!

[Andy M]

No I haven't done it but I know someone who has on a 250.I was told about a 250 using 5 gaskets. 2 gaskets would be fine, I wouldn't use silicone, make sure the surfaces are very clean. Chain needs to be same tension as normal, but you need some slack as you are in effect raising the head slightly. Tension it as normal making sure it is not too tight.
Thanks for the part number.

Edited by bo drinker, 09 February 2009 - 07:08 PM.

[pop1wheelie]

5 gaskets! I'm surprised the motor still fit in the frame. hehe You're welcome for the part #.
Thanks!!!!!

[helm]

Hi
why not go for the 22Occ Big Bore KIt try stuart at BPS contact details on the honda trials site
http://www.honda-tri..._sgg/f10000.htm
cheers helm

[pop1wheelie]

Thanks for the suggestion but I finally got an OEM piston.