sled Posted May 9, 2010 Report Share Posted May 9, 2010 My buddy just picked up a super clean 86 250r off an older guy. the bike looks to be in great shape, but I did a compression test today and it tested 105psi. the previous owner says the bike has only been rebuild once and I believe him. anyway I'm rebuilding it for my buddy and I wanted to add some other things to bring it to life a little more, I was not impressed with it's power. this is gonna be a woods/play bike. It's already got an LRD pipe. So what else should I do to it. I'm not signing on a 250r forum because I don't own it and I plan on doing this once. trying to stay away from porting. So what else should I do to it? can I get it to run with a bolt on banshee without porting or a big bore?? Quote Link to comment Share on other sites More sharing options...
Fastassbanshee96 Posted May 9, 2010 Report Share Posted May 9, 2010 My buddy just picked up a super clean 86 250r off an older guy. the bike looks to be in great shape, but I did a compression test today and it tested 105psi. the previous owner says the bike has only been rebuild once and I believe him. anyway I'm rebuilding it for my buddy and I wanted to add some other things to bring it to life a little more, I was not impressed with it's power. this is gonna be a woods/play bike. It's already got an LRD pipe. So what else should I do to it. I'm not signing on a 250r forum because I don't own it and I plan on doing this once. trying to stay away from porting. So what else should I do to it? can I get it to run with a bolt on banshee without porting or a big bore?? I would get a cool head and drop the dome size or mill the head. Jet it correctly. Gear it. Advance the timing. And put a v force3 reed in it. After that it should bump it up quite a bit. Quote Link to comment Share on other sites More sharing options...
esterelbanshee Posted May 9, 2010 Report Share Posted May 9, 2010 A friend of mine has one bored and stroked to 350 and it FLIES Quote Link to comment Share on other sites More sharing options...
cbn70 Posted May 9, 2010 Report Share Posted May 9, 2010 all depends on how much money he wants to spend. If you are doing the top end, get the 89 cr250 head gasket. It will increase the compression. A bigger carb will help. You could get a cool head with different domes. Go to eddie sanders webwsite. He makes different domes for bottom, mid range or top end. Biggest thing with mine was jettng it correctley. The stock jetting is so far off it is incredible. Quote Link to comment Share on other sites More sharing options...
VictorK Posted May 9, 2010 Report Share Posted May 9, 2010 I know you said you want to stay away from porting but exaust, porting, and intake/carb is the best mods on a R. I've built maybe 5 R motors and my favorite one on stock cylinder had a mid to top rpm port job, cool head with race domes, rad valve, 36mm pj, and bored 120 over. The 36mm seems wrong, you'd think to go right for the 38mm air striker but that set up tuned right is very fast Quote Link to comment Share on other sites More sharing options...
Fastassbanshee96 Posted May 9, 2010 Report Share Posted May 9, 2010 I know you said you want to stay away from porting but exaust, porting, and intake/carb is the best mods on a R. I've built maybe 5 R motors and my favorite one on stock cylinder had a mid to top rpm port job, cool head with race domes, rad valve, 36mm pj, and bored 120 over. The 36mm seems wrong, you'd think to go right for the 38mm air striker but that set up tuned right is very fast I'm actually in the process of doing a 250r for my brother inlaw... What is the stock jetting on those things and what's a good starting point for one with pretty much stock everything except for pipe and air box removed. Quote Link to comment Share on other sites More sharing options...
VictorK Posted May 9, 2010 Report Share Posted May 9, 2010 I just looked in my clymer manual, it doesn't say the stock jet size it only refers to them as main jet etc. Its been ten years since I ran a stock R carb, I believe stock main is like 165 on those.go up on the pilot one from stock and main 2 or 3 sizes then do a plug chop(ofcourse), then make adjustments if needed. When you verify the definite stock jet sizes let me know if the main is indeed 165 like my memory tells me lol I'm actually in the process of doing a 250r for my brother inlaw... What is the stock jetting on those things and what's a good starting point for one with pretty much stock everything except for pipe and air box removed. Quote Link to comment Share on other sites More sharing options...
Fastassbanshee96 Posted May 9, 2010 Report Share Posted May 9, 2010 I just looked in my clymer manual, it doesn't say the stock jet size it only refers to them as main jet etc. Its been ten years since I ran a stock R carb, I believe stock main is like 165 on those.go up on the pilot one from stock and main 2 or 3 sizes then do a plug chop(ofcourse), then make adjustments if needed. When you verify the definite stock jet sizes let me know if the main is indeed 165 like my memory tells me lol Well Im not sure if this is a stock carb or stock jetting. He just bought it not too long ago. Is the stock carb a kelhin? It looks like the intake boot is stock but I don't know a whole lot abot these things. I usually only work on banshees. Quote Link to comment Share on other sites More sharing options...
sled Posted May 9, 2010 Author Report Share Posted May 9, 2010 well, after talking to him tonight, I may send the jug out this week for porting. He wants to have it for a trip he's taking in 3 weeks, so I guess we'll see. I'll try bumping the compression and timing plate too. he's got his eye on making it beat our other buddies banshee which has a timing plate, T5's, and an air box. I don't know if it's gonna happen, but It'll be fun trying! Quote Link to comment Share on other sites More sharing options...
VictorK Posted May 9, 2010 Report Share Posted May 9, 2010 well, after talking to him tonight, I may send the jug out this week for porting. He wants to have it for a trip he's taking in 3 weeks, so I guess we'll see. I'll try bumping the compression and timing plate too. he's got his eye on making it beat our other buddies banshee which has a timing plate, T5's, and an air box. I don't know if it's gonna happen, but It'll be fun trying! hes gonna need porting to be faster then that banshee even then in a longer race banshee has a chance Quote Link to comment Share on other sites More sharing options...
VictorK Posted May 9, 2010 Report Share Posted May 9, 2010 Well Im not sure if this is a stock carb or stock jetting. He just bought it not too long ago. Is the stock carb a kelhin? It looks like the intake boot is stock but I don't know a whole lot abot these things. I usually only work on banshees. yeah keihin, I believe 34mm Quote Link to comment Share on other sites More sharing options...
sled Posted May 9, 2010 Author Report Share Posted May 9, 2010 hes gonna need porting to be faster then that banshee even then in a longer race banshee has a chance well, I'm looking into the ESR 310 kit now, didn't know they we're that cheap. might to do a woods port or an all around port with the stock carb and LRD pipe. do know how many different pipes LRD made?? I'm trying to figure out what kind of pipe it is, low end, mid range, top end, that kinda thing. thanks Bill Quote Link to comment Share on other sites More sharing options...
cbn70 Posted May 9, 2010 Report Share Posted May 9, 2010 the only 2 places in my opinion to get a 250r ported is eddie sanders racing in california or arlan at LEd(formerly of LRD). They can both build up a nice 250r engine. Many different ways to go if you want to go big bore. Sleeve a stock cylinder or go with a pro-x cylinder. Stock cylinder can go to a 310. Pro-x can go 310,330,350, and then larger if you want to put in a stroker crank. Anythinkg over a 310 will require to cases to be bored to get the cylinder to slip in. If you go with the pro-x go with the powervavle. No comparison to the non powervalve. You have the pipe, now would just need a larger carb to make it breathe. Both of those places have the cylinders on the shelf, or can get them quick. Getting you current cylinder ported could take some time with the shipping both ways as well as waiting in line to get ported. The 310 should be able to beat his buddies banshee, no problem. Quote Link to comment Share on other sites More sharing options...
VictorK Posted May 9, 2010 Report Share Posted May 9, 2010 well, I'm looking into the ESR 310 kit now, didn't know they we're that cheap. might to do a woods port or an all around port with the stock carb and LRD pipe. do know how many different pipes LRD made?? I'm trying to figure out what kind of pipe it is, low end, mid range, top end, that kinda thing. LRD has a big bore pipe, adjustable, and non adjustable for TRX250r's. I like the FTZ pipe for the TRX(inframe). thanks Bill Quote Link to comment Share on other sites More sharing options...
sled Posted May 9, 2010 Author Report Share Posted May 9, 2010 how do I tell?? the expansion chamber does unbolt in the center. Quote Link to comment Share on other sites More sharing options...
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