[macbig2k1]

Yes, I've made it by the same way.
All of my converted engines have a 125 crank case (up to 250 cc, next step for this winter 266.5 cc).

 

[buellzebub]

Thanks again Sebastian ?

 

[Boedy]

Okay, so I've read the entire thread. My question relates to the Raptor 250 crankshaft. You say that it will work, but will require different timing gears and chain, If you can run the Raptor crankshaft, then why can't the Raptor pistons be used?

My interest in the Raptor crankshaft is because I have recently discovered that Hot Rods, Inc. offers a +4mm stroked crankshaft with shortened rod that is a direct bolt in to the Raptor without the need for a cylinder spacer. On top of that, pistons are plentiful in a variety of sizes and compression ratios. I'm thinking that if I could make the Raptor crankshaft work, and put a bigger sleeve in, and run a 78 mm piston, well wouldn't that be nice?

If this isn't an option, what about using the Raptor inside cases, cylinder and head setup, with the TW longer drive axle? Or just use the Raptor pistons? I believe you wrote that the Raptor pistons cannot be used, is this because of a difference in wrist pin sizes or wrist pin position? Both of these problems can be overcome within the rod.

A lot, I know, but...

 

[lbxr]

Okay, so I've read the entire thread. My question relates to the Raptor 250 crankshaft. You say that it will work, but will require different timing gears and chain, If you can run the Raptor crankshaft, then why can't the Raptor pistons be used?

My interest in the Raptor crankshaft is because I have recently discovered that Hot Rods, Inc. offers a +4mm stroked crankshaft with shortened rod that is a direct bolt in to the Raptor without the need for a cylinder spacer. On top of that, pistons are plentiful in a variety of sizes and compression ratios. I'm thinking that if I could make the Raptor crankshaft work, and put a bigger sleeve in, and run a 78 mm piston, well wouldn't that be nice?

If this isn't an option, what about using the Raptor inside cases, cylinder and head setup, with the TW longer drive axle? Or just use the Raptor pistons? I believe you wrote that the Raptor pistons cannot be used, is this because of a difference in wrist pin sizes or wrist pin position? Both of these problems can be overcome within the rod.


A lot, I know, but...

I am gonna guess this raptor is a different engine family....

 

[Boedy]

Same family, but of course there are differences. Just trying to figure out what I can work around.

 

[Boedy]

Just for knowledge, I purchased a used Raptor 250 piston to size up against the 225 piston. I'm hoping to use the Raptor piston. I haven't gotten the 225 tore down yet, so I can't directly compare, but if anyone has the specs for the 225, TW, or XT250 piston, that would be great. My guess is, that the TW/TTR engines have a 15mm wrist pin, whereas the Raptor and new XT250 engines have a 17mm wrist pin. Easily worked around. Also, the wrist pin height could be different, also pretty easy to work around.

 

[macbig2k1]

OK, now I have time to write something.

I know, I've listed some Raptor 250 parts, BUT:
You can not use a complete Raptor 250 crank shaft!!!!!
The timing chain on the Raptor 250 and XT250 engine is on the right side. And you know, the timing on the TW engine is on the left side.

It would be a nice project to put a XT/Raptor engine into a TW frame.
-->> Has be done before by Yamaha as concept-bike.
-->> Search for XTW250
Maybe it's possible to put a TW output shaft into the XT/Raptor engine.

Yes, the Raptor 250 and the newer XT250 pistons does have a 17 piston pin.
But the TW200 (from 67 mm up to 73 mm) does have a 16 mm piston pin.

I know, there are big bore kit's for the Raptor/XT engines available, but these pistons are too big.
The 74 mm piston works and maybe the 76 mm too.

Now to the technical details:
The Raptor 250 and XT250 engines are nearly the same engines (it's comparable with the TW200 and XT225 engine).

Both engines
bore x stroke: 74 mm x 58.0 mm

Piston pin 16 mm
2008 - 2012 XT250

Piston pin 17 mm
2013.... XT250
2008.... Raptor 250


Both engines are using nearly the same con rod.
The eye-to-eye distance: 100,5 mm

Big pin diameter: 37 mm
2008 - 2012 XT250
TW225, XT225, TTR225, TTR230 and so on.....

Big pin diameter: 40 mm
2013.... XT250
2008.... Raptor 250


It's possible to use a Raptor 250 piston (compressions up to 13:1 available), but than you'll also have to use the Raptor 250/XT250 (2013....) con rod kit in combination with a different big pin. Because the big pin of the Raptor 250/XT250 (2013....) con rod kit is some millimeter too long.
And the big pin diameter are bigger, so you'll have to modify the crank shaft.
-->> Bigger bore for the bigger big pin.

I've done this for my TW250 MX engine.
But I haven't had the time to install this crank.


And I've made some small updates into the first post.

 

[Colotw200]

Anyone know if a ttr 250 cylinder could be used? My buddies uncle has one that he might be parting out. It has a 73 mm stock bore, could it be bored to 74 mm instead of having to sleeve a smaller cylinder? Also, after rereading the first page for the thousandth time it says "The 225, 230 and 250 cc engines does have the same cylinder head". Will the tw200 head work or do i need one from a 225?

Thanks, Mike

 

[macbig2k1]

The TTR250 is a different engine, will not fit.

The YFB/YFM250 head will fit.
-->> This engine doesn't have 250 cc (it's a 230 cc)
But the cylinder heads are nearly identical.

The TW200 rides don't have to change the cylinder head.
This is the reason, why I haven't added other compatible cylinder heads.

 

[Colotw200]

Thanks for the clarification. Was hoping to avoid the cost of sleeving a cylinder to get closer to 250cc but it appears thats not going to happen. I already have a ttr 225 cylinder is it safe to bore this one to 73mm? Or should i look for a YMF250 to bore. Thanks for your patience.

 

[macbig2k1]

There is no big difference between the 225 and YFB/YFM250 sleeves.
I've checked a PDF (by Advanced Sleeve).
225 - O.D.: 2.998"
250 - O.D.: 2.999"

The 73 mm pistons are made by Woessner for the YFM/YFB250.
They wouldn't produce them, if it isn't save.

 

[Yamaman]

First I want to the time to Thank Macbig2k1 and everyone else that has contributed to this post!! your hard work is greatly appreciated!! Heres a little background for me. I'm from Taiwan and I ride a Yamaha SR150 thats only sold here and Mexico. From what I understand the engine is a de-bore / de-stroke XT/TTR/TW. 57mm bore X 57.8mm stroke with the engine code 3UR. I'm currently gathering parts to do a full rebuild and I would love to have you guy's opinions. I will be using a complete head from a 2006 XT225, and XT225 connecting rod pressed on to my crank. I'm also planing on getting the Webcam389a with upgraded valve springs. My initial thought was using the TTR230 cylinder (4VW-11310-00-00) paired with wiseco piston (4312M07000). But now I'm thinking, if I'm going to do it, I might as well go big and do the 250cc. A re-sleeved (4VW-11310-00-00) with LASleeve (YA-5400) paired with XT250 piston (3C5-11631-00-A0). What do you guys think I should do? What are the pros and cons of these different combination of engines? Again, I want to thank you guys for paving the road for someone like me. Your opinion will be greatly appreciated by me!! Thanks everyone!!

 

[Purple]

You lost me at "re-sleeved (4VW-11310-00-00) with LASleeve (YA-5400) paired with XT250 piston (3C5-11631-00-A0)" - but then that's not unusual

Welcome to the board

 

[littletommy]

Welcome!!

 

[Jeff707]

Sebastion,

I ran my stock 2007 TW200 out of oil on a long ride (yes, I'm a dunce--should know better). I likely spun a bearing at the very least. I just bought a 2004 lower from a shop in Canada. I read your list above but I'm still unclear. Can I upgrade my piston to a TTR 225 piston without changing the crank and keeping the stock cylinder? I'm thinking I might add a little more power since I have to rebuild the upper anyway.

 

[Badgerflorida]

Jeff - might want to send a private message as this thread has some age to it. Welcome and cheers and sorry for your misfortune.

 

[elime]

You can use a 70mm piston but the cylinder wall will be thin. I and several others on the forum have done it. It works out to 214cc. DO NOT use 70.5mm. That is to big.

A stock TW crank will work but it lowers the compression ratio a little bit. For example, a Wiseco piston for a 225 rated at 10.25 to 1 will drop to 9.9 to 1 with the TW crankshaft.

My guess is if you ran out of oil you trashed the small end of the connecting rod. I have seen one example of this happening on this forum. Shop ebay for a 225 crankshaft with con rod and swap it out with the larger piston. You will end up with a 225 with 10.25 to 1 compression, if you use a Wiseco. Buy a large assortment of carburetor jets off AliExpress, richer and leaner than stock, and go to town tuning it. I ran slightly leaner jets on my TW 214 and it loved it !!! Of course gloom and doom was predicted but it ain't happened yet and it has been a lot of miles, sea level miles, since I did it. Good luck.

 

[ben2go]

Can the TW cylinder block be bored out for a larger sleeve? I've seen this done on other air-cooled engines. I helped assemble one that was done like that. The engine case may need to be machined to accept the larger sleeve base.

 

[Rpmfly1]

Has anyone ever thought of putting bushings in the oversize piston pin holes to make them 16mm? Just a thought from what I use to do with pistons in bikes I motocross raced in the 1970's and 80's! Press and hone to fit brass with oil hole drilled! Very simple then test fit for deck height! If our deck height was low, we drilled the hole lower to raise piston and vice versa. Pinned bushings to not turn if need be but never needed.

 

[DougDotyTW200]

I am surprised someone in the US has not started a send it in to be done and send it back upgrade service. Seems all the recipe of figuring it out part has been done.