Author Topic: TRX250R what to do next???? (Read 8562 times)

jimi · « **on:** December 27, 2015, 12:36:29 PM »

I just got a 1986 TRX250R and it has a fmf pipe, cool head, ....I am going to get some Reeds and go to a 310, but was wondering would or should I go to a long rod? or keep it stock on the bottom end? will I get the same power? and is there any other motor tips? Im not trying to be the fastest and it going to be a MX build, so no dunes, or mud...Just track and trails, and desert play. Thanks.....

thesmith87250r · « **Reply #1 on:** December 27, 2015, 12:41:11 PM »

Well if ya want a l 310 you will need a +4mm crank

jimi · « **Reply #2 on:** December 27, 2015, 12:51:38 PM »

ok then I will start looking for one... Thanks thesmith87250r.

jimi · « **Reply #3 on:** December 27, 2015, 12:53:50 PM »

Will a 310 be enough power to compete with the 450s...or bigger? 330,370. not looking to build a rocket. just want to race.

huntertools · « **Reply #4 on:** December 27, 2015, 01:17:35 PM »

First, do you have shocks that are set up for you and for MX? Second, can you out ride the motor you currently have on a MX track? If the answer is no to either one, I think you should hold off on the motor work. Not trying to tell you what to do just friendly advice. Good shocks and conditioned rider are hard to beat on the track. Good luck!
Allen

havinnoj · « **Reply #5 on:** December 27, 2015, 01:41:12 PM »

You're doing this work to a stock cylinder? If so, have you considered bolting on a 300/310 kit from ESR? Might be more cost effective and better gains.. http://www.eddie-sanders-racing.com/product_p/310%20cylinder%20kit.htm

jimi · « **Reply #6 on:** December 27, 2015, 05:19:54 PM »

looking at the ESR 310 and YES on shocks. PEP front and rear

Saber569r · « **Reply #7 on:** December 27, 2015, 09:19:46 PM »

The esr 310 kit is nice. Mine was the trx11 port. Didn't see much of difference from my 310 to 330 but the 350 was a lot more bottom end. Get a builder kit send it to led he does a great mx motor.

klotzkid1992 · « **Reply #8 on:** December 27, 2015, 09:37:25 PM »

jimi check your squish clearance with a piece of solder. lot of good info about that on the web. I just checked mine on my new purchase (86trx with 85atc250r motor in it) and it was fairly simple. Im glad I checked it, my motor ran just fine but the squish clearance was .096" measured with a mic. Carlos from BDT reccomends .050" being the optimal measurement when checking this with the solder method. the head gasket that was on my machine measured .044" thick so i am going to run a .010" thick head gasket, recheck with solder and either shave my head or deck my cylinder to get my dome closer to the piston in that .050" range.

The norm · « **Reply #9 on:** December 27, 2015, 11:29:34 PM »

I have a esr 310 cylinder set up by Pete at hybrid engineering with a +4mm rod. It is a very impressive motor. It was originally set up by Carlos and ran horrible. Overheating all the time because of an improperly set up dome. He put a 17.5-1 compression dome in it when a pump gas dome was ordered. I would highly recommend using a different builder and definitely disregard anything carlos says. Pete took my pos bdt motor and made it into a real powerful little 310.

2ndmoto · « **Reply #10 on:** December 28, 2015, 02:07:20 AM »

I can second LED. I have been running Arlan's (LED/LRD) motors for 15+ years on my 2 strokes. He has been doing my 4 stroke motors too. He has been into motors weel before the 250r, and has many national and international championship wins.

I hear nothing but good things about Pete at Hybrid. There are several people running his motors on this site. ESR is also good bang for the buck, but getting support can be hard at times.

Most people on this site will warn you to steer clear of BDT. Lots of people very displeased. Do your homework before sending a motor off to anyone.

Best regards
-Jason

Saber569r · « **Reply #11 on:** December 28, 2015, 10:53:07 AM »

My hybrid sphynx I bought from skean1 is a beast. Great bottom end with great top end. He's be a good option too.

hontrx265r · « **Reply #12 on:** December 28, 2015, 12:36:15 PM »

Im getting ready to list a nice ctracing ported 330. It will include the piston, new rings, and gaskets. Its still std 76mm bore. Piston is used but in good shape and so is the cylinder. These are not the most ballistic but they have lots of power and are very reliable. Pm if your interested. It is also a pro x cylinder casting which are top quality cylinders.

jimi · « **Reply #13 on:** December 28, 2015, 04:52:08 PM »

I will build my own motor. Been rebuilding 2 strokes for a long time. will not pay someone to do what I can.

rk88r · « **Reply #14 on:** December 28, 2015, 06:40:54 PM »

Esr kits are a great value. At minimum have a reputable builder set up your head. Honda left a lot on the table there. That and race gas will make a big difference. If you do that measure your squish before teardown.