Ok i have a 1988 250x with the modds listed in my profile.. or album or what ever that thing iz... Im looking to at about 10 more horses out of the bike.. Im pulling like 31 right now.. i would LOVE in the 40 range... If i add a Stroker crank to the bike and A sparks Ignition system that lets me rev out to 10,000 will that get me where i need to be?? also what size crank? 4mm, 6mm? or what powroll sells the 12.7mm stroker crank.... I dont have a problem sending the engine out and getting the cases cut to fit it or anything like that but i need to know what kind of power i am looking at here? and iz it worth the trouble??thanks... also anyone know who i would have to sent it 2??

 

If your really into racing this, you should look into a 350x motor. They will bolt in with little extra time. Other wise get it dynoed, then talk to them about what would really make it go. But rember that that bike is almost 20 years old. May want to put your money towards a new R,Z or YFZ

 

nah this is just like a big hobby for me.. I am racing MX with it.. but i dont want to step up to the bigger class right away.. also right now im runnin 400's.. I just like the sleeper aproach 2 things... I dont want a 450r or yfz b/c u see 2 many of them there getting old really fast.. + this bike feels really nice sits perfect not high like the other bikes feel.. + i already have suspention and everything else whats 500 bucks more to be runnin with the 450's??? the bike weighs 300 pounds right now.. ( lighter than the 450's) But i need like 10 mor horses out of it.... I dont want the 350x engine b/c i can beat one right now like i am.. i have alot of cash rapped up in the bike and just looking to put more.. LOL i will get some pictures soon.. I love MX racing but seriosly how fast do I need to go on the track.. Me and the 450's that race there also are jumping the same lengh the only thing they get me in is the holeshot.. not by much but they do... so can some one help me out?? ( IM NOT GOING TO BUY A 450!! Please dont say do that)

 

If you have to money For the Sparks Ignition Go ahead.. Just make shure that Your motor is Built Really Good 10,000 Is a Lot.. I have a buddy that Stroked his 250X and it is the bigest Stoker Kit He Could find.. He told me That If you do that to Go ahead and Home the cylinder and Mabey if you can get Over Sized Piston rings..

 

Oh no I have a 78mm big bore kit installed.. Ported and polished MX style, New timing chain, 11 1/2:1 compression piston, Bigger valves, bigger intake and exhaust, proformance valves, proformance cam, Advanced machining said i was at a 307cc bike right now... I also have a 34mm mikuni flat slide on the bike, FMF pipe with header, Uni airfilter, BArnett clutch, im gonna get a new piston and timing chain and cam ( b/c it has alittle wear on it) to go along with the bike when i put the crank in it.. Im also gonna put a Hot rod in it.. advanced machining said i this would push me up 2 a 340x LOL well Im hoping this and the Igniton system will set me up just Fine!!! I am right beside a stock 400ex right now... Im running a 14/38 gearing... with 20inch tires,, Im hopping to smoke the stock 400ex and move on up into the modded ones!!! If im pullin 40hp or more i shouldnt have a problem.. I am pretty sure i have more stuff done to the bike.. but its late and i cant really think 2 good... well if there iz more i will be sure to post..

 

I think that you should go get yours dynoed, it would amaze me if your pushing past 25hp. If your not into the 450 then get a 400ex, I just don't think your seeing the point that I am trien to make here.
Sounds like your a really good rider but cann't out run them on the track ie your bike is too slow for your abilities.
If you have a buddy that would let you race once with there's you would see that your old 250x is good but you can do better on a new more powerful fourwheeler

 

I see the point ur making and i have rode my friends 400ex and the power just isnt there like mine iz i have more bottom end and smoother power throughtout gears.. Now the 400ex and mine have the same exact top end I mean exact its who ever gets off the line is gonna win tha race.. I kill them in the trails Like enduro riding.. The bike right now is perfect for the track.. just needs alittle more bottom end to it.. powroll sells a crank thats 12.7mm so i am gonna purchase that this summer and then get the sparks Ignition system and see how that feels.. The only other bike i really like that had some Major dig to it and is quick as heck is my dads modded lt250r But im not switchin to 2 stroke LOL I have dynoed my bike.. it said it was pulling 28 or 29 i have to find it down in the basement.. I am wantin like 10 more horses out of the bike and i know i can get it! its just the set up i need..

 

my stock manual says its pulling 19 hp something like that.. again im going off of memory