[ronnydog]

Very nice work and effort Ron.

Thanks, a lot of unknown area for me.

 

[icpchad]

GREAT JOB...



Okay,

Now the big question...how much to do it for all of us. I am in line first.

No doubt! This guy is smarter than Yamaha and about to make a million dollars. ;-)

 

[Bagger]

RD, Good On You !!! I am so glad that you got this done and I am hoping you have a sillly grin everytime you even think about riding it!

Now you need to bring it up here to WA and go Elk hunting with us! I'll uh, watch your bike while you're out in the woods . . . . .

Great Job Sir.



Bag

 

[ronnydog]

RD, Good On You !!! I am so glad that you got this done and I am hoping you have a sillly grin everytime you even think about riding it!

Now you need to bring it up here to WA and go Elk hunting with us! I'll uh, watch your bike while you're out in the woods . . . . .

Great Job Sir.



Bag

Bag, Its is really fun and I hope a lot of you get to ride it. I found a bag oring on the intake manifold that let air in and made it impossible to jet. Now that I'm close to the right jet 118 or 120 it hits a wall at 7/8 top speed and I thing the carb is to small. I talked to a moto mechanic friend and he changed the carb on his wife's TTR225 to a larger carb I think he said a 35mm and it flys. I am picking up a used TTR225 carb, intake tomorrow and hope to get it on this week. This is all new to me just learning as I go.



And Thanks



Ronnydog

 

[qwerty]

Your big displacement will run out of cam first, then carb. One really won't make much difference without the other. A little porting and polishing and valve work will help get the top end rpm back. I've crunched the numbers and even 10,000rpm will still have a piston speed low enough to avoid ring flutter and such. xr100.com will sell you all the parts except an exhaust to build a 250cc (74mm bore) TT-R 230 that makes 28hp for about $1600. Then stuff the TT-R guts in a TW case with a remachined countershaft. Use the 62mm crank and you'll be knocking around 266cc.

 

[Gerry]

Whats going on there Mr. Dog? I think you are spending too much time riding that high powered scooter up and down the street. What ever it is you're doing, you deserve the break. Good job on your project. Gerry

 

[ronnydog]

Your big displacement will run out of cam first, then carb. One really won't make much difference without the other. A little porting and polishing and valve work will help get the top end rpm back. I've crunched the numbers and even 10,000rpm will still have a piston speed low enough to avoid ring flutter and such. xr100.com will sell you all the parts except an exhaust to build a 250cc (74mm bore) TT-R 230 that makes 28hp for about $1600. Then stuff the TT-R guts in a TW case with a remachined countershaft. Use the 62mm crank and you'll be knocking around 266cc.

Querty, you may be right about the cam and carb. I need to try both and see if it helps. I talked to Frank at XL100.com great guy and very knowledgeable, he has a cam with a 254/258 duration and 380/359 lift and lobe centers at 104/108. What is your thought about his cam or the Web cams for this motor? I know so little about cams. Thanks



Ronnydog

 

[ronnydog]

Whats going on there Mr. Dog? I think you are spending too much time riding that high powered scooter up and down the street. What ever it is you're doing, you deserve the break. Good job on your project. Gerry

Mr Giz, Always great to hear from you. Yes I am having fun with this little beast in the dirt and on the street. I can't help but smile when I twist the throttle and it raps up to speed and oh yea I forget sometimes that it has an extra gear. Takes a little to get used to.

Thanks for the missing link, sometimes I think I am missing a link or a brick short when I do these projects with little or no knowledge of what I'm doing. This is a great place for the help I need, Thanks for the input from all! Russ was a big part of this with many hours on the phone. Thanks



Ronnydog

 

[TWrider]

Mr. Dog. I highly suggest you get the head professionally ported...CNC port is about $450. Talk to some raptor 250 builders, I believe the port layout is very similar. Also, convert the cam to roller bearings , and go up to the raptor 35mm intake valve. Do that and you're probably going to need the mikuni 33 pumper and a larger header...high 20's in HP are achievable.

 

[ronnydog]

Mr. Dog. I highly suggest you get the head professionally ported...CNC port is about $450. Talk to some raptor 250 builders, I believe the port layout is very similar. Also, convert the cam to roller bearings , and go up to the raptor 35mm intake valve. Do that and you're probably going to need the mikuni 33 pumper and a larger header...high 20's in HP are achievable.

Twrider this is all good info and I'm shure it would help the performance. I did some port and polish but not a $450.00 job. The cam has a roller bearing on one side and I do not think the 35mm valve will fit. I'm looking at the 32mm Mikuni flatslide carburetor after the cam.



Ronnydog

 

[TWrider]

Twrider this is all good info and I'm shure it would help the performance. I did some port and polish but not a $450.00 job. The cam has a roller bearing on one side and I do not think the 35mm valve will fit. I'm looking at the 32mm Mikuni flatslide carburetor after the cam.



Ronnydog

yes I think it can fit, but it may require opening the bowl a bit, I hope you did work on the valve tower inside the port, they come in way too far on the tw, ttr, raptor, and modifying them is the best way to improve velocity and flow.



Port Package With +1mm Intake Valve MK-RAP250HD1CT head porting with short guides, a radius Race valve job, and a +1 Intake valve. CT flow ports the head for maximum performance. Short valve guides are installed as the stock guides are excessively long and hinder flow/performance. CT then does a performance 5 angle radius valve job to ensure maximum horsepower, blending the valve job to the port work.



$489.95



valves only EC-KW-80-805**



Stainless Steel +1mm Oversize Intake Valve

Larger and still lighter than the stock intake valve. $30.30



http://www.ctracing.com/raptor_250.htm



PS : a needle bearing roller can be used on the small side of the cam if the bore is enlarged, probably not necessary unless you have the thing at freeway speeds constantly, (which you might with all that extra power)



CT has a special custom grind cam ( it won't work on the 225, because yamaha moved the chain to the other side) but you should call them, tell them what you've built, and find out what duration they recommend. Then have Web cam make you a one-off.



Raptor 250 Web CT Grind Camshaft ($90.00 core charge or send us your cam)This is a custom grind cam with a longer duration for more rev than anything you will find directly from Web.



$123.00

 

[ronnydog]

yes I think it can fit, but it may require opening the bowl a bit, I hope you did work on the valve tower inside the port, they come in way too far on the tw, ttr, raptor, and modifying them is the best way to improve velocity and flow.



Port Package With +1mm Intake Valve MK-RAP250HD1CT head porting with short guides, a radius Race valve job, and a +1 Intake valve. CT flow ports the head for maximum performance. Short valve guides are installed as the stock guides are excessively long and hinder flow/performance. CT then does a performance 5 angle radius valve job to ensure maximum horsepower, blending the valve job to the port work.



$489.95



valves only EC-KW-80-805**



Stainless Steel +1mm Oversize Intake Valve

Larger and still lighter than the stock intake valve. $30.30



http://www.ctracing.com/raptor_250.htm



PS : a needle bearing roller can be used on the small side of the cam if the bore is enlarged, probably not necessary unless you have the thing at freeway speeds constantly, (which you might with all that extra power)



CT has a special custom grind cam ( it won't work on the 225, because yamaha moved the chain to the other side) but you should call them, tell them what you've built, and find out what duration they recommend. Then have Web cam make you a one-off.



Raptor 250 Web CT Grind Camshaft ($90.00 core charge or send us your cam)This is a custom grind cam with a longer duration for more rev than anything you will find directly from Web.



$123.00

Thanks again TWrider for the great info! I have more to look at than I thought.



Ronnydog

 

[trailway]

What ever happened with this project? I would love to see some more of this..

 

[joeband]

this project was really awesome to see the results! from a different angle, is there a reason the parts for a tw225 have never been brought over here? is it the same case with just a bigger cylinder?

 

[rmcglad55]

ronnydog is a genius! If he wanted , he could make a bunch of money modifying bikes for members of this forum.

 

[mrbracket]

Ronnydog, any new info on your TW250?? Would love to hear more about how it's holding up and such... Thanks, great work!

 

[ronnydog]

Ronnydog, any new info on your TW250?? Would love to hear more about how it's holding up and such... Thanks, great work!

I needed to get another bike to put the 250 in so I could change carbs, cam, etc and still have a bike to ride that I trusted . I found a 1991 tw for $800.00 and will swap the motors soon. I am very excited to get back at it and will add pics of the progress and performance as I can. Makes me smile just looking at it.



Ronnydog

 

[assquatch20]

I needed to get another bike to put the 250 in so I could change carbs, cam, etc and still have a bike to ride that I trusted . I found a 1991 tw for $800.00 and will swap the motors soon. I am very excited to get back at it and will add pics of the progress and performance as I can. Makes me smile just looking at it.



Ronnydog

Remember to swap stators to keep things from frying or dying.

 

[ronnydog]

Remember to swap stators to keep things from frying or dying.

Thanks assquatch20 good info!

Ronnydog

 

[kenfyoozed]

Ronnydog, any updates?