I go pick up my new 05 RM 250 Friday and I am thinking of going to a big bore kit (I race mx against a lot of 450s). Anybody got any ideas on who and how big? Any other info and things to do and watch for would be very helpfull. This is my first Suzuki.
I don't think you need a big bore to beat a 450. Infact, I know not. I can pretty much hand a four stroke its ass on drag stretches, woods, and mainly tracks, as my 250's slide better, are lighter, and just plain faster than any 450. This is talking from everything except a Suzuki, so I can't help you there. I just know that everybody here at our tracks are moving back to two strokes.
You can spend your dollars on big bores, but the four strokes are still going to win if they have already been.
I traded emails with Rick Peterson (RPM's Big Bores) on this subject - he has not built any lately but is willing to build a 285cc kit - he would have to work with tuning details though on porting, jetting, etc. It should be fairly similar to the YZ285 kits he regularly puts out, since both the RM250 & YZ250 cylinders are almost identical....
Actually I just came off of an 04 CRF450. Have not had a 2 stroke since my 01 CR250. ALL of the guys I normally race locally are getting 05 CRF450s and I just thought it would be fun to holeshot every moto next year on a two stroke after listening to them all talk crap about how they are dead. :nener: The RPMS RM285 would be cool but dang that guy is pricy. Any body know were he gets those 71mm pistons? The site says Wiseco but i dont see that piston in any of their catalogs. If I could get my hands on one of those I would send the whole thing to Eric Gorr and let him do the work.
They are custom made for him by Wiseco. So the only place you can get a replacement is directly from him, which means he gets to charge whatever he wants for them. :ohmy:
Checked with Eric and 265 is as big as he goes and its about a 4HP gain for $475.00. Max power says they get 8HP out of a 265 kit and offer an offset bore 285 kit that is 10+HP. $700 for the 265 and $1000 for the 285. After talking with both of them I believe Eric more. I like the way he explains EVERYTHING he does to your motor and why. Anybody have any dealings with these two or any of these size kits before? Was it worth the cash? I remember riding a buddies CR265 years ago and it was the smoothest 2 stroke I had ever been on at the time. Can't remember who done his???
A non-peaky 8 HP gain from a modern RM250 with just porting and 2mm overbore smells fishy to me. The 4HP gain sounds more reasonable. Eric knows his stuff and I don't believe that RPM can do anything better.
Stick with what Eric and Rich have to say. They are honest, knowledgable, and professional. Other suppliers may have a tendency to inflate expectations in the interest of securing your business.
More horsepower will not make you a faster rider. The same guys that beat you this week with your stock 250 will be the same guys that will be roosting you next week with your big bore kit. The money would be better spent practicing or attending a MX school.
Seems like 2 strokes have been getting plenty of holeshots at the SX races...When I go to the local track I see 2 strokes taking the start all the time in the 250 class.
Hade Eric do a 310 on my KX, been riding it for 6weeks now (16 hours of run time) it runs so good I am very impressed. Best money I have spent on the bike. In tuning it I tried a number of reeds,pipes, timing and jetting settings this motor likes the stock pipe over a PC, any reed, straight up timing and almost stock jetting. I am sorry I didn't do it sooner I love it. I would do it again in a heart beat. Ed
Couldnt say it better than Sideways. Totally agree. Spend money so you can ride more, if you already ride as much as you can and want to spend money on the bike then spend it on things that make you ride faster and longer, such as suspension, steering dampers and all those things that reduce armpump. My latest buy(still in shipping) is a trick flexible handlebar thats suppose to help armpump. At $299 its pretty costy for a handlebar but well worth the money if it helps reducing armpump. Much more worth than say, a pipe, that in most cases only makes you tired faster and is not possible to take to the next bike.
Well...the word is that although the YZ and Rm cylinders are almost identical, the RM (and the CR) don't have the wall thickness allowing it to go the full 285cc and can only get to 285 with a slighty longer stroke. The YZ/KX cylinder can go the full 285 without touching the stroke.
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