mx 250r help

[profab]

i am going to build a new motor for my 250r for mx . i ride alot of indoor stuff small tracks. was looking at esr 330pv kit with 4mm stroke crank or lrd 350pv kit. i had seen were someone had posted a 310 kit with stroke crank had made the most hp and rev much better then the larger kits. i ran a 265 this year i did not like it seem like it was way off on hp made alot of changes pvl ing was a big help bike ran alot better after i got off the line but it hurt it bad off the line.would like some opions on what size and who to go to also is the pv worth it . i like the hit on a 2 stroke am i going to lose it with the pv thanks mark

[fiveOnick]

Well first off there is a new cylinder coming out from CP industries. Im not exactly sure how soon it will be out but there are several different variations. He is building a 68mm bore 265 as labeled motor that would be size legal for you and make more hp than your current setup. A well built 265 can run pretty close with a built 450 for MX, but the thing is an R stock cylinder is easy to extract a good bit more hp out of but getting that last bit of refinement with the head is expensive. This new jug should have a good bit more power potential than a Pro-X jug which has more than a Stock jug.

For one thing you need to ditch the PVL, while it is a good ignition it is not a MX setup. You need a flywheel, a CR ignition would work but honestly I would put the stock stuff back on with a lightened flywheel and a Dave Moore TNT CDI. They are hard to get but should be more available soon.

You also need to address you pipe and carb and reeds what do you have, there could be some considerable hp there to gain.

Do you want to go bigger, or would you rather have a better performing 265 if you can?

[profab]

I run the 30+ class so, cc's don't matter. I was thinking I wanted to get somewhere around 60hp. I figured I would have to go with some type of big bore and/or a stroked crank. If the CR ignition is what I need, then that is what I will go with. I liked the PVL because of the quickness of the rev over the stock ignition but, it may have been the poor running motor I had that is the reason I didn't like it with the stock ignition. I do understand the reason for having the flywheel for MX. I have a set of V-FORCE reeds and a set of CR250R reeds. On this motor, I seem to like the V-FORCE better. I have a 34mm stock carb. and a 38mm AIR STRIKER. I couldn't really tell a difference when I swapped them. I have a PAUL TURNER race pipe and a PAUL TURNER woods pipe. We ran the woods pipe because it helped out quite a bit on bottom end. I was thinking I would probably get a new SPARKS TT pipe. I think I will need one of the bigger engine set ups to run with the 450's. Most of the one's I run against, are highly modified, running around 48 to 55hp. Where can I find info. on the CP cylinder you were telling me about? Is it goung to be offered in a big bore?
Thanks alot for the info.
Mark

[fiveOnick]

It will be a 265, 314, or a 344 for the cylinder that accepts all TRX bolt ons. I would suggest the 314, I doubt you will need a stroker crank to get around 60hp out of this jug. Im not sure when they will be out and developed, but I would say they should start popping up in the next few months. I wouldnt waste the time on the Sparks TT pipe, it is a great pipe for sure but the ESR TRX5 is the way to go. Performance is nearly unbeatable for an inframe and the price is cheap.

[profab]

who will be sall the cyl and who would be the best to port it thank mark

[fiveOnick]

I dont know who will be selling it, probably as many retailers as there are selling the cub, same company. I honestly doubt it will need any porting for MX, but I cant really say since it isnt out yet.