I recently tore apart my R to rebuild my main bearings and seals but since it's already tore, I will change the piston/rings and some others bearings. I will as well give a little 'treat' to my cylinder/cyl. head... A porting/milling job

My question is about that. I was wondering about something...The 250r Compression ratio is 7.7:1... Would bringing it to about 10:1 (If it's doable)(Like a 250 mx bike) + a mild porting job bring the HP to a realistic mid-40 hp's?

Seems realistic since a 250 MX bike have about 50 hp. Don't know if it even have sense since I'm not an engine builder myself so I'm not sure if everything I stated is doable...

I'm still asking since there are a lot of knowledgeable people around here....



Thanks a lot in advance [img]i/expressions/face-icon-small-smile.gif[/img]

 

Are you doing this yourself? You must really love that quad!! LOL
Can't really help you, never owned a trx250r. But I have heard using a cr head gasket will give you a little. I'd do that before shaving or decking it. Maybe the base gasket is thinner and will work too??

 

Yep doing that myself lol (excepting for the porting/milling)...Long job but fun lol...I have heard of the CR gasket but I don't think it will really up the compression...Maybe 5 pounds of static compression at most I suppose. Don't know what the Compression Ratio would be then though !


Thanks for the ideas and passing by,

Pierre-Yves

 

I'm sure you'll have some hard core honda guys in here giving you some good advice. One thing I have heard (Don't know if it's true, but it happened to my buddys 250R) is that it's pretty common for the crank seals to go on these so maybe you should consider replacing them while she's on the table.

 

Thanks again Sparky ! Can't wait to get some of those Hardcore Honda Fans in here [img]i/expressions/face-icon-small-smile.gif[/img]






As for the mains seals problem...



[img]i/expressions/face-icon-small-tongue.gif[/img][img]i/expressions/face-icon-small-smile.gif[/img]




Pierre-Yves

 

http://www.exriders.com/vbb/forumdis...?s=&forumid=49
This is where you want to be if you have a 250R. Everyone here seems to focus on the 450R. You'll find tons of helpful information at atvriders.com.

 

Thanks a lot [img]i/expressions/face-icon-small-smile.gif[/img]

Nice R of yours by the way, keep it alive [img]i/expressions/face-icon-small-wink.gif[/img]

 

send the head and jug to cut the head it will be 50 and porting ?????

 

I'm sorry, it's maybe because my first language isn't english, but I don't understand your post [img]i/expressions/face-icon-small-blush.gif[/img]

 

i will cutt you cylinder head for you for $50 and port the cylinder head/jug in the usa