Guys, I recently picked up a completely bone stock (virgin) TRX250R. This thing was 100% original down to the tires. Heck, the cylinder & piston haven't seen daylight since it was assembled at the factory (standard bore) It starts up right away, idles fine and runs great. Anyway I took it down to Pismo Dunes for the Labor Day weekend to try it out and I wasn't impressed with the stock power. I have never owned one before so I didn't know what to expect. Well the thing is just to darn slow for the power robbing dunes. It is in desperate need of additional power to haul my 200Lb carcass through the dunes at a brisk pace. I know adding a pipe is a big help, but I want to go further. I want it to be able to run neck and neck with piped, jetted air box modded Banshee's. My friend added a 310 kit, pipe, jetting, reeds & air box mods to his and it runs pretty dang sweet. Does that sound like what I need? Any help on what I should/could do to get it to run faster would be greatly appreciated.

Rude Dog

 

Go with a 330 big bore kit and stomp your buddy.My friend has a full race 310r and it is a beast but I rode a 330r today and that thing could stomp a 310.Just my 2 cents maybe I know nothing.[img]i/expressions/face-icon-small-shocked.gif[/img][img]i/expressions/face-icon-small-cool.gif[/img][img]i/expressions/face-icon-small-happy.gif[/img][img]i/expressions/face-icon-small-confused.gif[/img]

 

i pipe will make a big difference, but if your looking to compete with banshees and what not then g owith a big bore kit.... as for myself im looking into a 350 powervalve kit.. if all goes well i can get it in the shop within the month =)... go to the esr website and they jave a BOLT-ON 330 kit so you dont have to machine your cases. good luck

 

i went with the ct 330 kit so i could still race 250 class but if your more in to dunes and got the money get the 350 powervavle kit.

 

The best bang for teh buck is the 310 kit from CT or teh bolt on 330 from ESR. The bolt on 330 is actually a 310 bored out to it's limits (I belive. If you want to go with a true 330 or 350 then your cases will have to be machined to fit the larger sleave.
Go to the Dune Zone on ATV Connection and check out the Project SandTrax articles.

Cya in the dunes!

 

talk to a guy on here that goes by the name of SANDTRIX. he builds fast a$$ 250R's

 

Thanks Guys for all the advise!!! I'll check into the different kits. I think either the 310 or the 330 will work for me.

Mike330r: You said the 330 kit is a 310 bored to it's limits!!! Is that like it sounds? It's basically on it's last bore? IE: If you have throuble, need to bore the cylinder you can't as there isn't enough matl left? Meaning the whole cylinder is basiclaly junk, ka-poot, toast a boat anchor?

Rude Dog

 

the pro x cylinders have a nikasil sleeve so once youve used all the bores all you have to do is resleeve the cylinder.. im not sure what costs are involved but its penny's compared to buying a whole new cylinder

 

All I can say is ESR330,I have never seen a 330 go like ESR's,not to dog any other builders but when I go that route...........ESR all the way,thats just my opinion,what I would want,they straight up-flat@$$ rip,but go w/ a builder that does what YOU want,good luck to ya[img]i/expressions/face-icon-small-smile.gif[/img]

 

The 330's and 310's are nice torquey motors.
I used to have a 330 myself, but I blew the bottom end out of it.
I now have a ported polished, yada yada 250R that will keep up with and even beat slightly modified Banshees.

You say it is on the stock bore.
Well my friend it is WAY past due for another piston and rings, and probably an entire bore job.

After that, put an aftermarket pipe on it such as a Paul Turner, or an ESR. Also you will want an aftermarket air filter such as a K&N to allow more air into the engine.

If you do not have a thousand dollars to dump into the quad, this would be the best way to gain about 6-10 H.P.

Chances are the rings are pretty worn by now, and sooner or later the piston will fatigue to the point of breakage.
Then things will get real expensive real fast!

There are many more things that can be done to make your 250R faster also, but this is a good place to start.

Don't get me wrong, I may one day have another big bore, but for now, there is NO dune I can't get my 200+ lb but up and over.

I particularly enjoy the treeshots, and hillclimbs on the Oregon coast.[img]i/expressions/face-icon-small-happy.gif[/img]