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klutchbuster250
06-08-2007, 11:58 PM
k so i have 20 inc tires in the rear and i love them but i lost to much top speed im at like 50mph and with the 22inch i was at like 55 to 56mph, so my question is how much would i gain with a rev box? will i be at 55mph like withe the 22inch tires but still runing 20's? i was thinking on getting kenda knarly xc in 21 to gain some top speed back and if i add a rev box do you think il be bakc at stock speed or maybe slightly higher?

ALEXANDERJASON
06-10-2007, 07:03 PM
HAVING HAD MY REV BOX ON FOR A WHILE, I'LL CHIME IN ON THIS ONE. I DON'T THINK THESE REV BOXES ARE AS MAGICAL AS THEY CLAIM TO BE. I NOTICED BETTER IDLING, BETTER THROTTLE RESPONSE, AND THE INCREASE IN THE REV LIMITER, WHICH MADE FIRST GEAR ALOT MORE USEABLE.

ASIDE FROM THOSE BENEFITS. I DON'T THINK IT IS REALLY LENDING ANY HELP TO TOP SPEED, AT LEAST THAT I CAN FEEL OR NOTICE.

I THINK IT IS WORTH THE MONEY FOR WHAT IT DOES. ESPECIALLY SINCE I ONLY PAID $50. IF YOU READ SOME OF MY OTHER POSTS, YOU WILL SEE WHERE I TALK ABOUT HOW THE NEUTRAL LIGHT STAYS ON ALL THE TIME, BUT NOW I AM ABLE TO START IT IN ANY GEAR. KIND OF A COOL FEATURE IN MY OPINION. NOT SURE IF THEY ARE ALL LIKE THAT. I HAVE AN '07 250EX WITH THE AMR REV BOX.

I HATE TO BE ONE OF THOSE "BUY A 450R LIKE ME" GUYS, BUT SINCE I DON'T HAVE A 450R, I'LL SAY IT.

THERE ARE LIMITS TO THE 250, AND FOR WHAT IT IS, IT'S A GREAT BIKE. THE 300 OR 400EX ARE FAR SUPERIOR MACHINES. SUSPENSION, CHAIN DRIVE GIVING MORE TORQUE, AND LARGER DISPLACEMENT FOR MORE POWER.

IF THERE IS ANY WAY TO SWING IT, YOU MAY WANT TO CONSIDER A DIFFERENT MACHINE. I RODE A 400EX FOR A DAY, AND IT LEFT ME WANTING MORE THAN WHAT I COULD ACCOMPLISH BY SINKING ALL THE MONEY IN THE WORLD INTO MY LITTLE 250EX.

NOW, THAT BEING SAID, IF THERE IS NO WAY TO SWING A NEW QUAD, THEN IN ALL HONESTY, UNLESS YOU JUST HAVE THE MONEY TO BURN, I WOULD NOT BUY PERFORMANCE PARTS FOR THE 250EX.

FYI - I HAD MY 250EX DYNO TESTED, AND I RAN 15.1 HP. STOCK WAS 11.7. THE ONLY PERFORMANCE MODS I HAVE ARE UNI AIR VENTS IN MY LID, A NEW PHOENIX ENDCAP FOR MY STOCK EXHAUST FROM EBAY, THE AMR REV BOX. AND A BAD *** TECHNICIAN THAT REJETTED MY BIKE TWICE AFTER RUNNING IT ON THE DYNO A FEW TIMES. HE SAYS HE CAN GET MORE FROM CORRECTLY JETTING A MACHINE IN CONJUNCTION WITH A DYNO, THAN WITH MOST BOLT ON AFTERMARKET PARTS, AND HE PROVED IT.

NOW, TO ANSWER YOUR QUESTION, WE RAN THE DYNO WITH THE STOCK REV BOX, AND IT WAS 15.0 HP. TECH SAID THAT THAT WAS NOT ENOUGH DIFFERENCE TO DEFINITIVELY PROVE THE REV BOX DID ANY GOOD.

I STILL LIKE THE ABILITY TO START IT IN ANY GEAR. AND IT IS DEFINATELY EASIER TO START WHEN COLD!!

ALTHOUGH IT REVS HIGHER, IT DID NOT SHOW ON THE DYNO THAT IT INCREASED HORSEPOWER, WHICH KIND OF SURPRISED ME.

SORRY FOR THE LONG ANSWER!!

klutchbuster250
06-10-2007, 08:55 PM
thanks for the help and yea i know the 250 has its limits but i wasmainly wanting t find a way to be at stock top speed with the smaller tires, so do u suggest me getting a rev box to go along with my full exhaust and filter? would it help alot i like the fact that i will be able to start in any gear , where did u get ur rev box?

ALEXANDERJASON
06-10-2007, 09:29 PM
I STILL DON'T THINK YOU WOULD BE BACK TO TOP SPEED THAT YOU HAD BEFORE, BUT IF THE OTHER BENEFITS ARE WORTH THE MONEY TO YOU, THEN I WOULD GET ONE.

I BOUGHT MINE FROM AN INDIVIDUAL OFF EBAY. CAUGHT IT AT THE RIGHT TIME WHEN NO ONE ELSE WAS LOOKING I GUESS.

klutchbuster250
06-10-2007, 09:41 PM
k thanks for the help im gonna get one soon but first i need some risers and front spacers then im ordering a dyno jet kit and the rev box to perfectly jet my bike , thanks again !

mx825
06-10-2007, 09:45 PM
yo klutch. i have some 5in spacers i need to sell. pm if you're intrested.

tedwilley
06-10-2007, 10:46 PM
I have to second everything ALEXANDERJASON said. There are finite limits to what you will ever get out of the 250ex, performance wise, or for that matter suspension wise.
The only positive thing I saw from testing the Big Gun rev box yesterday, was different shift points, which I liked.
As far as performance, at this point my ex runs better with the stock CDI. I think I need to do some rejetting because my fuel mix seemed way rich with the rev box, and pretty right on with stock. Makes no sense to me, but I emailed BG, and hope they respond with something constructive to try.
Right now I would say for $50 it's interesting for $100+, it seems unnecessary.
You would need to know some more about the gearing, specifically have many axle RPM at redline in fifth gear in order to calculate whether the extra 1000-1500 RPM would really regain what you have lost with smaller tires. Too much work for me!
BTW where are all of you guys riding that 5-6 MPH at top end is so important?

klutchbuster250
06-11-2007, 03:41 PM
well i have to street ride alot to get to the trail and to my friends hose that he owns property down the street and any litle extra will benicebut not really neccesary and alot of my trail are sandy wide open trails and i need those extra rpms,also i think it would do alot more with the filter and full exhaust i have

tedwilley
06-11-2007, 04:26 PM
Well, you guys are lucky. Out here on the left coast, especially Central CA, everything is 3/4 to 2 hours away. That explains why you guys are able to open it up!
BTW, my 250ex does 85 MPH! On my trailer...

klutchbuster250
06-11-2007, 04:44 PM
i live in florida 2 houres from miami , i originaly lived in miami til lastyear but my trails are like 10 min from my house and in miami we have to hit alot of backstreet and one avenue lol me and my friend have ridden like 40 minout of our way on the way home on our atvs to a mcdolnalds :devil:

hellshot00
04-20-2008, 10:58 AM
I just ordered a AMR stage 3 rev box but i get no spark what stage do u have alexanderjason?

prairiemonster
04-20-2008, 11:26 AM
Originally posted by klutchbuster250
k so i have 20 inc tires in the rear and i love them but i lost to much top speed im at like 50mph and with the 22inch i was at like 55 to 56mph, so my question is how much would i gain with a rev box? will i be at 55mph like withe the 22inch tires but still runing 20's? i was thinking on getting kenda knarly xc in 21 to gain some top speed back and if i add a rev box do you think il be bakc at stock speed or maybe slightly higher?
The only way to change top speed at this time in a 250 is by tire height.All the other bolt on stuff will help you get from 0-top speed faster but not add more top speed.
A repeat statement,you will get more performance out of a hot coil
than a rev-box.