[macbig2k1]

Hi at all,

I've seen very often the question:
How can I get more cc??

Here are some combinations without (200 crank - 55.7 mm stroke) and with changing the crank shaft (225 crank - 58.0 mm stroke) up to 250 cc.
Important, you'll never have to change the cylinder head. The 225, 230 and 250 (YFB250, YFM250 [NOT Raptor]) cc engines does have the same cylinder head.

without / with changing the crankshaft:
214.4 cc / 223.2 cc
- 70 mm piston with 10.25:1 compression ratio
- original cylinder can be used
OR
- 225/230 cylinder (70.00 mm std. bore) can be used, but than you have to use the first oversize (70.50 mm)

220.5 cc / 229.6 cc
- 71 mm piston with 8.7, 9.5:1 or 10.25:1 compression ratio
- original cylinder can be used, but needs new 225/230 sleeve
OR
- 225/230 cylinder (70.00 mm std. bore)
OR
- 250 cylinder (71.00 mm std. bore) can be used, but than you have to use the first oversize (71.50 mm)

226.8 cc / 236.1 cc
- 72 mm piston with 8.7:1 or 9.5:1 compression ratio
- original cylinder can be used, but needs new 225/230 sleeve
OR
- 225/230 cylinder (70.00 mm std. bore)
OR
- 250 cylinder (71.00 mm std. bore)

233.1 cc / 242.8 cc
- 73 mm piston with 9.5:1 compression ratio
- original cylinder can be used, but needs new 225/230 sleeve
OR
- 225/230 cylinder (70.00 mm std. bore)
OR
- 250 cylinder (71.00 mm std. bore)

239.6 cc / 249.4 cc
- 74 mm piston with 9.5:1 compression ratio
- original/225/230 cylinder can be used, but needs new 250 sleeve (74 mm std. bore)


Compatible cylinders:
70 mm std. bore
-> 29U-11310-03-00
1986 - 1987 TT225
1986 - 1988 YFM225
1983 - 1986 YTM225
-> 3RW-11310-00-00
1999 TT225
1999 - 2004 TTR225
1992 - 2000 XT225
-> 4VW-11310-00-00
2005 - 2013 TTR230
-> 5MP-11311-00-00
2001 - 2002 XT225
-> 5RK-11311-00-00
2003 - 2007 XT225

71 mm std. bore
-> 3GH-11310-00-00
1989 - 1991 YFM250 (not Raptor)
1989 YFU1W
-> 4BD-11310-00-00
1992 - 2000 YFB250
1998 - 2004 YFM250 (not Raptor)
-> 5XG-E1310-00-00
2005 - 2009 YFM250 (not Raptor)


cylinder sleeves:
70.00 mm std. bore
YA-812 - LA Sleeve
3143FA - Advanced Sleeve
1986 - 1987 TT225
1986 - 1988 YFM225
1983 - 1986 YTM225
1999 TT225
1999 - 2004 TTR225
1992 - 2000 XT225
2005 - 2013 TTR230
2001 - 2007 XT225

71.00 mm std. bore
YA-5101 - LA Sleeve
3315FA - Advanced Sleeve
1989 YFU1W
1992 - 2000 YFB250
1989 - 2009 YFM250 (not Raptor)

74.00 mm std. bore
YA-5400 - LA Sleeve
1996-06 TT-R250
YA-5679 - LA Sleeve
15.2308 - ProX
2008.... XT250
2008.... YFM250 Raptor


Compatible 225 cc crank shafts (58.0 mm stroke):
-> 1KH-11400-00-00
1986 - 1987 TT225
-> 3RW-11400-00-00[/B]
1999 TT225
1999 - 2013 TTR230
1992 - 2000 XT225
-> 5MP-11400-00-00
2001 - 2007 XT225
Attention:
- This crank needs a different timing chain and sprocket
- here are the needed parts:
timing chain
-> 5MP-12176-00-00
2001 - 2007 XT225
-> 5XT-12176-00-00
2008 - 2013 YFM250 Raptor
2008 - 2013 XT250
timing chain sprocket
-> 94591-87104-00
2001 - 2007 XT225
-> 94582-19104-00
2008 - 2013 YFM250 Raptor
2008 - 2013 XT250


Compatible pistons:
Wiseco 10.25:1 Yamaha TTR225 / TW225 / XT225 / XT230 / YFM225 / YTM225
70.00 mm - 4312M07000
70.50 mm - 4312M07050
71.00 mm - 4312M07100

TKRJ 9.5:1 Yamaha TTR225 / TW225 / XT225 / XT230 / YFM225 / YTM225
-->> Made like OEM / Yamaha piston
-->> Pistons over +1.00 are not always available
70.00 mm - AY0880X (PY1160X)
70.25 mm - AY0881X (PY1161X)
70.50 mm - AY0882X (PY1162X)
70.75 mm - AY0883X (PY1163X)
71.00 mm - AY0884X (PY1164X)
71.25 mm - AY0885X (PY1165X)
71.50 mm - AY0886X (PY1166X)
71.75 mm - AY0887X (PY1167X)
72.00 mm - AY0888X (PY1168X)

Wiseco 8.7:1 Yamaha YFM250 (not Raptor) / YFB250
71.00 mm - 4675M07100
71.50 mm - 4675M07150
72.00 mm - 4675M07200

Woessner 9.5:1 Yamaha YFM250 (not Raptor) / YFB250
71.00 mm - 8659DA
71.50 mm - 8659D050
72.00 mm - 8659D100
72.50 mm - 8659D150
73.00 mm - 8659D200

Yamaha 9.5:1 XT250 2008-2012
The XT250 2013, 2014... piston will NOT fit, this years does have a 17 mm piston pin.
The Raptor 250 pistons will also not fit. Same problem, 17 mm piston pin.
74.00 mm
3C5-11631-00-A0 - piston
4XV-11603-00-00 - piston ring set
5H0-11633-00-00 - piston pin
or
15A-11633-00-00 - piston pin
93450-17044-00 - piston pin clip (2 needed)

Fitting top end gasket kit for 74.00 mm piston
W5745 - Wiseco for YFB250 / YFM250 (not Raptor)


Regards,
Sebastian

 

[Borneo]

You are such an impressive guy.

 

[macbig2k1]

Just a small collection of my knowledge, collected in the last years.

 

[vanillagorilla1]

good god thats a great list. I cant wait to read the piston list too. I read someplace about having to make a cylinder base spacer. In any event this is great!

 

[ronnydog]

S

Just a small collection of my knowledge, collected in the last years.

Some day I will be in Germany and will stop by and enjoy you brilliance!

Ronnydog

 

[macbig2k1]

I've added pistons to the list.

 

[Leben]

Thanks Sebastian, it's nice to have all of that information available in one post. You have been very helpful in sharing your knowledge.

 

[TopPredator]

Mac. When you upgrade the motor to 250cc do you use the original OEM carb and if you do is it difficult to tune up? Does it idle well?

 

[macbig2k1]

The TW200 wasn't sold in Germany.
Here are just some less imported bikes.

So, I can't tell you how well the OEM carb works.
I use at this time the Mikuni VM28-418 flatside carb.
The carb is OK for lower rpm, but a bit to small for the higher rpm.

It's not easy to tune the carb.
The biggest help is a lambda meter, mine is from Koso.

I use it with a narrow band sensor, this is the low priced option.
http://www.kosoeurope.com/a/f-ratio-mini-style-lambda

The meter with wide band sensor is better, but a bit too expensive for me.
http://www.kosoeurope.com/wide-band-a/f-ratio-meter-lambda

 

[TopPredator]

The TW200 wasn't sold in Germany.
Here are just some less imported bikes.

So, I can't tell you how well the OEM carb works.
I use at this time the Mikuni VM28-418 flatside carb.
The carb is OK for lower rpm, but a bit to small for the higher rpm.

It's not easy to tune the carb.
The biggest help is a lambda meter, mine is from Koso.
View attachment 12038

I use it with a narrow band sensor, this is the low priced option.
http://www.kosoeurope.com/a/f-ratio-mini-style-lambda

The meter with wide band sensor is better, but a bit too expensive for me.
http://www.kosoeurope.com/wide-band-a/f-ratio-meter-lambda

Thanks Mac. I would hate to turn my reliable 200 into something I have to constantly dick with. Plus I'm not a motorcycle mechanic.

 

[macbig2k1]

OK, I don't understand everything -> "constantly dick with"???

You'll need the lambda meter not the whole time.
You'll need it just for the first time, to get a fitting setup.

You don't need much mechanic skills to adjust the carb. If you can read and understand the Mikuni manual, than you can do it.

And one more I can tell you, the 250 engine is reliable.
It worked perfect on my last 3h hare scramble enduro race.

 

[vanillagorilla1]

OK, I don't understand everything -> "constantly dick with"???

I'm not a great dictionary, but here goes. "having to regularly work on, or high maintenance".

 

[CJ7_TW]

Guess what I did before I decided to first, thread highjack and second go off on a tangent then try and be polite>>>>

It strikes me as funny whenever you have people with a slight language barrier. I grew up and had family come over to 'Merica early-mid 1700 century due to the political climate, potato famine whatever (Irish). I also have native american in there somewhere just to balance things out. When I was in Giessen, Germany late 90's; I learned German. There are many words that have no translation to English and phrases that make not "a lick of sense" to English only readers.

Mac, please don't be offended if I read between the lines in the wrong way with how you came back with what I read as a question: "OK, I don't understand everything -> "constantly dick with"???"" Leads me to believe that you didn't fully understand that he was asking if he had to do continuous maintenance with it to keep it running perfectly. Then you came back with the perfect answer. Your english is a million times better than my german so maybe you understood/maybe not. I am sooooo appreciative of the words (which you essentially did): use this plus this to get more power without killing reliability. Use this meter, read this book for this size carb adjust once for altitude and done. On a side note, I wonder how difficult it would be to shoehorn the FI from the XT250 to the TW. I'm too busy to squeeze the minutes out of the day to not make fun more of a priority (but I can daydream).

Humor is much the same way... "constantly dick with", wait whuut?! What does constantly using your dick with even mean? Do I need to think MORE with or about my penis? What about "bat-shit crazy"? Is that someone who has some kind of obsession with bat-shit? Some of the military euphemisms for homosexuality always had me holding back laughter and sometimes not successfully which is what the Drill Seargents were going for so they could surround you like a pack of wolves waiting for you to say/do something wrong. And last but not least, I'm not homophobic and I don't care if some forum member is so it's not going there.

 

[TopPredator]

OK, I don't understand everything -> "constantly dick with"???

You'll need the lambda meter not the whole time.
You'll need it just for the first time, to get a fitting setup.

You don't need much mechanic skills to adjust the carb. If you can read and understand the Mikuni manual, than you can do it.


And one more I can tell you, the 250 engine is reliable.
It worked perfect on my last 3h hare scramble enduro race.

Thanks for all your expertise I wish your shop was closer I would gladly pay you to increase the horse power in my TW. Sorry for the American slang. Sometimes I forget that our little forum is worldwide.
rick

 

[Skyking]

Hi Sebastian,
Great post. Thank you.
i'm confused(nothing new); but isn't the head, and it's tiny little valves the limiting factor for getting more power out of the 200? How then is the larger combustion chamber able to breath, and how do you get by with a 28mm carb?
Humor me,
Larry

 

[elime]

Sebastian -- Thank you very much for sharing the information. Very generous of you. Tony

 

[Skyking]

^ for a response.

Hi Sebastian,
Great post. Thank you.
i'm confused(nothing new); but isn't the head, and it's tiny little valves the limiting factor for getting more power out of the 200? How then is the larger combustion chamber able to breath, and how do you get by with a 28mm carb?
Humor me,
Larry

 

[elime]

You stated a 70mm piston can be used in the original cylinder. The outside diameter of the cylinder below the fins is 72.5 mm. This makes the cylinder walls only 1.25 mm. Is this enough? It seems very small to me. Tony

A drawing to help me explain:

 

[macbig2k1]

Thank you for the translation, but you don't have to do it.
I understand the most of the technical English. Only with "slang" I have some problems.

I am sure, you're measured only the lower end of the sleeve and you haven't measured the part of the sleeve, which is inside of the cylinder.

The outer diameter of the sleeve is 73 mm -->> wall thickness 1.5 mm with 70 mm piston.
This is OK, 1.5 mm is thick enough.
My engine performance tuner does have sometimes thinner sleeves inside of his engines (under 1 mm) and it also works well.

It's the same like the 140 cc kit for the 125 cc engine.
60 mm piston inside of a 63 mm sleeve (outer diameter).

 

[macbig2k1]

Hi Sebastian,
Great post. Thank you.
i'm confused(nothing new); but isn't the head, and it's tiny little valves the limiting factor for getting more power out of the 200? How then is the larger combustion chamber able to breath, and how do you get by with a 28mm carb?
Humor me,
Larry

Hi Larry,

sorry, I haven't seen your massage.
I don't think, that the valves are limiting factor.
On my street TW I am using the original valves, 71mm piston, 58mm crank shaft and 28mm Mikuni flatside carb in combination with the WebCam high performance cam shaft and the full Akrapovic exhaust system.
Result: 22 hp / 21 Nm
-->> 20 hp with OEM exhaust

The size of the carb, depends from the driver type:
- small carb for the best performance in the lower rpm
- big carb for the best performance in the higher rpm

Cam shaft and exhaust system are optimized for the higher rpm range, just the carb is a bit too small.
My problem is to find a bigger plug'n'play fitting carb.


If you want a bit more performance without changing the combustion chamber, use a performance cam, piston with higher compression and a high quality performance exhaust system with a direct bended header pipe.

Sebastian