Hi I have a stock 254 evo. would like to know if putting a 1mm stoke crank will give me any more power and rpm. without any other mods? thanks Joe

Without mods ... not likely much if any at all ?

hi Scott thanks for the reply. would raising the intake and exhaust ports help? thanks Joe

Being most RCMK Evo's are factory set at @ .018/.022" squish clearance ( must check tho )
Adding a +1 mm stroke ( Which is @ .039" ) Means piston travels @ .0195" higher at TDC and same amount lower at BDC.

So ... The cylinder is GOING TOO be raised to maintain correct squish clearance.
This raises ex timing a tad, but lowers intake open duration an equal amount.

To get these engines to really light off and run hard ( Like modified race engines do )
You absolutely must fine tune the port open duration specs and port areas to get engine breathing better. The Cranks +1 specs are really secondary to finding more power and rpm, +1 stroke will just give engine more torque overall and as stated before, unless mods are done to the cylinder itself power gains by just stroking would be minimal at best.

JMO ...

Hi Scott thanks for the info.I will keep the motor stock for now. may be later I will have some one do a mod job for me. thanks Joe

Joe when you are ready to get your Evo modded look into Motorheads RC his knowledge and workmanship is top shelf!