JUst wanted to know if you could changed the cylinder of a cr 250 with a 250r if so what advantages would you have. Also can you use a cr's ignition on a 250r

 

Try contacting FTZ racing for your cylinder question, they build them. "www.ftzracing.com"

I think that the ignition is a direct bolt on with the ability to run a powerjet carb.

 

the only problem with a cr cylinder on a trx is the inability to utilize the powervalves, however, better port layout, nikasil sleeve, and more cooling are the good things about this. you might want to call CT or Duncan, as they are developing a powervalved cylinder using RAVE valves for the TRX

 

Well, you have a few options for a different 250R cylinder. I have heard of people modifying the CR cylinders to fit a TRX. I actually have a CT RAVE cylinder on the way. It was not cheap though! The CR ignition does not just bolt up either, you must make some modifications because the CR is a 2 bolt mount while the TRX is a 3 bolt mount. That is not a cheap mod either. It is true that you can run a power jet carb with the CR ignition, but that is an expensive carb as well. I am running the CT cylinder and head, with a High Rev pipe, 38mm PWK and CR250R intake.

 

Ray: gonna let me take that cylinder for a test ride? hehe

 

Quarryboy,
To better answer your question we need to know what type of riding u are going to be doing. I talked with Allen at CT racing last week about the new Pro-X with the powervalves. For drag racing and TT racing he recommended the non powervalved cylinders because there is less exhaust drag with them but for MX or X-country he suggested the Powervalved cylinder. Personally i would go with the Pro-X 310 non power valved cylinder for just the cost aspect($400 cheaper) and it has the same HP figures and a little better torque figure then the powervalved 250 Pro-X. I was also talking to LRD and they suggested to have the stock cylinder resleeved to the big bore and with this setup they are getting 2 HP more then the Pro-X 310 cylinder they sell. :You can get this done by them for about $250.

 

JC makes a good point, but my motives for the 250 Powervalved cylinder are that I will be using it to race in the 250 class where the 310 is obviously illegal. The aftermarket 310 cylinder would probably be a better way to go because of the Nikasil option and the better cooling, where as you are just replacing the sleeve on the stock cylinder. I don't think that the difference between the sleeve and the Pro X cylinder is 2 HP.

 

The 2 HP gain is not my figure but LRD's figure. I have found that over the years that there figures are pretty accurate for there torque and Hp #'s. Plus if you are not racing the nikasil feature is not that great. Granted that the extra cooling of the Pro-X is nice but the R's don't have a problem with overheating and if you put a water temp gage on them there is no difference in the coolant temp between the 2 cylinders (Pro-X & stock) under normal riding conditions. Basically it comes down to how much $$$$$$$ you want to spend and how high tech you want to go. Along with Nikasil you have the chance of damaging the Nikasil and having to get that redone which isn't cheap but on the other hand you have to have a regular sleeve bored. For the average rider it is probably cheaper to stay with the stock cylinder have it ported and pay the $35 to have the piston ceramic coated and put a dry film lubricant on the skirt.