99 and 98 cylinder interchangable?

[pre-game]

I read on here that the 98 cr 250 had different porting than the 99 and made for a better motor most people voted, i was wondering if i could buy a 98 cylinder and put it onto my 99 and keep all the same internal stuff like the powervalve and piston (66.4 mm) ive gouged the 99 jug and am about to send away for it to get welded and re-plated, but for 40 bucks or so more i can get a new jug, and have options.. anyone know about this??? thanks guys

 

[dirt bike dave]

Yes, the '98 cylinder is interchangeable with the '99.

With the more aggressive porting, you may notice slighlty higher fuel consumption and slightly shorter piston life. Many people prefer the '99 for trail riding, while the '98 is preferred for more aggressive moto.

FWIW, the same basic CR250R engine design was used from like '92 - '01, but there were changes to pistons, heads, carbs, pipes, ignition and jetting. As for swapping a '98 jug onto a '99, there should be no problems.

 

[pre-game]

the head and powervalve will all transfer though correct? thanks for the info

 

[dirt bike dave]

the head and powervalve will all transfer though correct? thanks for the info

I am 99.9% certain all the powervalve parts will interchange. I am 100% certain that your '99 head will bolt onto a '98 jug, and the '98 jug will fit onto your '99 bottom end.

I used to have a '99 and had a shop manual for it. The main differences with the '98 and '99 were the porting, the pipe, the ignition and the carb. I had a '97 ignition and carb on my '99. The black box controls the powerjet carb on the '97 and '98. I am not sure if the combustion chamber in the head were 100% identical between 97 - '99, but since you are using the '99 piston, you should be safe with the '99 head.


FWIW, you can view part numbers and microfiche for the '98 and '99 at the Service Honda website. If you need any parts such as bearings for the powervalve shaft, they have good prices, too.

 

[Pete Payne]

yep , it will all transfer over !