TW200 and TW225 engines will fit.
Got an 2002 Yamaha TW125 standard with the square headlight.
I love it and got slightly attached to it so can't bring myself to sell it to get a faster bike. So I want to strip it and make it a custom and fit a bigger engine to it.
Do any of you know any engine that fit well into them? I can do frame mods but obviously dont want to do to many
TW225 engine is a bolt-in. TT-R225 and XT225 engines are not. Better be sure which 225 you are talking about.
For some reason I have the idea that a Serow 225 is the euro version of the XT.
It is not necessary to swap the entire transmission. The TW countershaft can be ground down to accept the XT or TT-R 6-speed. You will also need to use the TW case cover with the outer support bearing for the countershaft. I don't know for sure whether or not the XT and TT-R cases are capable of oiling the countershaft support bearing. Those with whom I've spoken who actually have big displacement and/or 6-speed TWs are built on the TW200 or TW225 cases with the XT/TT-R parts. I'm sure the builders would have used the XT/TT-R cases had such a conversion been easier.
Serious misuse of punctuation leaves me wondering what the hell you are trying to say?Why wouldn't they? there are some differences in crankcase ventilation, but I don't think oil flow, The TW just uses a slightly lower profile case side output bearing and seal to fit around the larger shaft diameter...Not sure if a xt clutch cover would fit the TW brake pedal either. In either case (6 speed mod or 225 bore up or xt225 engine) you need to split cases to install a TW output shaft....Only one he wouldn't have to split is a tw200 engine, or went to japan for a tw225 engine. The only reason to really bore out the TW cases is if you want your stock engine numbers.
Serious misuse of punctuation leaves me wondering what the hell you are trying to say?
Okay, I understand now. Your best bet, from my research, is to use TW cases and mix and match whatever 200/225 engine parts you want. I cannot find any info on the XT and TT-R cases having the necessary oil passage to lubricate the outboard countershaft bearing on the TW. Maybe they do, maybe they don't. The 125 and 200 cases need to be bored to accept the XT/TT-R cylinders. There are other cylinders from other 200/225 bikes and 4-wheelers that will also work.
The stock TW countershaft can be ground to accept the 6-speed trans from the XT and/or TT-R. The 6-plate XT/TT-R clutch will bolt in to the TW, and the TW case cover can be used. Tdub already has a XT clutch with Barnett friction plates and springs--bullet proof but drags a bit when cold. I thought about buying parts to build a 278cc TW with a 6-speed, but it would be cheaper in the long run to buy a wrecked XT225 and a wrecked TT-R230, disassemble, compare/choose/remachine parts, build the TW the way I want, and then eBay the leftovers.
Honestly, I don't remember which "crankase cover" (that is what Yamaha calls them) I used. Too many years ago. The covers are not marked. I did nothing about any kind of "ventilation". I've noticed no "ventilation" problems over the last 29,000 miles since installing the clutch. If there is a "ventilation" problem I'm way to stupid to know.The six disk clutch will HIT the inside of a TW clutch cover (which you call a case cover) so it cannot be used. If You use an XT clutch cover that allows a six disk clutch to be used, then you will block a ventilation passage because the 225 cases it is meant to go on are different...If you have tw200 cases, use a tw200 clutch cover/5 disk clutch unless you know what the heck you are doing.