Might be some info for you here. I just did a search for --head swap
Me living in holland am not able to get the smallest amount of grunt out of my TW.. this said i have to confes that my TW only has 125cc. So i was wondering if it was possible to swap out my 125cc top end and put a 200cc top end in. I already was able to imagine i would have to change the piston arm out for a different one so that the piston would have a bigger stroke but besides that.. My idea's draw a blank..
Is this idea possible? Has this been done already ( i could find any post on this on the old or new forum but you never know..)
my idea was to buy something like this:
1990 87 00 Yamaha TW200 TW 200 Trail Way Cylinder Jug with Piston | eBay
would i have to bore anything out the bottom end?
would the 125cc "hat" fit on the 200 cc top end?
any help would be amazing!
A upgrade from 125 to up to 250 ccm (bore x stroke: 74 x 58,0 mm) is possible.
No, you have to use a 200/225 head. The 125 valves are much too small.
The needed parts:
- 200/225/230 cylinder head
- 200/225/230 cylinder
- 200 crankshaft (55,7 mm stroke)
- 225/230 crankshaft (58,0 mm stroke)
- piston, available from 67 to 74 mm
If you have a DE01 with a 4 disk clutch, than you have to buy a new clutch pressure plate to convert the clutch to 5 disks.
This is the absolute minimum.
The 5 disk clutch works fine till 230 ccm (my engine, 22hp).
For more ccm you have to use different clutch springs with some spacers to get a bit more pressure on the clutch disks.
But it's better to install a new clutch boss and pressure plate to convert your "4 disk-4 spring" clutch to a "5 disk-5 spring" clutch.
These parts are not expensive, you can get it for ~100-120 EUR.
With a used (cheaper) clutch basket you can upgrade to a high performance "6 disk-5 spring" clutch (up to 44 Nm torque).
Look for an XT225 Serrow engine, all the parts are there but you may have to mill out the crank cases, hobble toghether a 125 / 225
ok thanks, one noob question tho..
are all XT 225's "serrow" engines?and will the head of the XT also just sit on the bottom of te TW? because if so.. i think i'll have to make a rebuild and make a manual alongside of it to..
 just found the wiki page on the 225 thanks anyway's