hitting the rev limiter now

[eotrx400ex]

i finished the 416 rebuild w/ a stage2 Hot Cam. now it hit's the rev limiter fast in first, second and third. i have stock gearing an 18" rear tires.
before the rebuild i didn't have this issue but of course its a different machine now.
so what route should i go??, different CDI?, mess with the sprockets? when the rear tires wear down i'm going back to the stock 20".
also i read on a site that a CDI from another honda (trx250 maybe?)will work on the 400's and it raises the limiter 1000rpm.anyone else heard of this?

[a4guy]

I hear of people upping the rev limit but my opinion is that it was set to a certain rpm from the factory for a reason. I would add a tooth to your drive sprocket or upgrade tire size. This will give you a higher top end and change the gear curve. You will not hit the limit as fast. That is my opinion and I am sure others have theirs.

[99exrider94]

yes i do believe that the 250 does work however i think you should go with the sprocket route

[honda400ex2003]

what exactly are you looking to do? make it go faster or not hit the limiter so quick? it can decide what you want to do. if you want faster and longer limit times then gear to a 15/38 or 16/38. even a 15/36 would be good with the 18" tires. it would be better with the 20" imo. dont waste your time on the cdi. steve

[JOHNDOE83]

Are you sure your hitting the limiter and not running to rich?

Im just wondering, they almost sound the same.

[eotrx400ex]

I agree with you a4guy about the rev limiter and stock configured motor but with a non stock cam i was thinking that therory might not apply so much?

an for your question honda400ex2003...BOTH go faster with out hitting the rev limiter :D lol. i agree about the tire size i'd rather have 20" on back but a little short on the $$$ at the moment for tires. think i will focus more on gear.. after addressing JOHNDOE83

that is a great question JOHNDOE83 that is something that crossed my mind!! its a very good possibility is running rich. at a steady low to moderate speed the ex will surge some. i tried to adjust some with the pilot screew or fuel screew thinks its also called but that didn't affect idle at all really. based on zrpilot thread thinkin i need to clean the carb, it has a 155 main and a 42 pilotjet. thinking the needle is in middle setting...cant remember for sure

[sc400ex_rider]

LOL i kept my stock CDI so it wouldn't blow up. stock CDI is 9800 the high rev ones add 1000 RPM. the 350x cdi works and has no limit, some use xr250r boxes also. I would rec HD spring and the 450r cam chain if you want to play in high rpm land. any bike will hit the rev limiter if you hold it to long in 1 gear. you just need to shift faster. I read on here that stock (99-04 15/38) gearing w/18" was best for mx.

[Wheelie]

Stock rev limit is 9100.

[eotrx400ex]

Originally posted by sc400ex_rider
LOL i kept my stock CDI so it wouldn't blow up. stock CDI is 9800 the high rev ones add 1000 RPM. the 350x cdi works and has no limit, some use xr250r boxes also. I would rec HD spring and the 450r cam chain if you want to play in high rpm land. any bike will hit the rev limiter if you hold it to long in 1 gear. you just need to shift faster. I read on here that stock (99-04 15/38) gearing w/18" was best for mx. its doing it way to fast to be something alone the the lines of not timing the shifting. think im gonna focus on the jetting for now

after you did the monor work and went to a stage to cam did you rejet it ? 155/42 is what your running thats close to what im running on my 440 stage 2 with p&p heads 450r carb. im runnig a 155/50 so you mite be to rich like johndoe83 said. what carb are you running? i was running 148/38 with the stock carb.

[jcs003]

certain CDI's are designed for a specific curve of a specific ignition system. dont mix them up even if they do work.

[aDviSol2y]

I had the same issue and I just plugged in a BigGun CDI and it fixed my issue. I have had it like this for years now with no issues. With a built motor, you are going to run in the higher RPM range, thats why you build the motor, so it can handle it.

[eotrx400ex]

Originally posted by ericcrip
after you did the monor work and went to a stage to cam did you rejet it ? 155/42 is what your running thats close to what im running on my 440 stage 2 with p&p heads 450r carb. im runnig a 155/50 so you mite be to rich like johndoe83 said. what carb are you running? i was running 148/38 with the stock carb. no i didn't rejet. i did the 42 cause that what sugested after removing the choke..and that jetting worked. as for the main an going with 155. thats the smallest i could find at my local shop.while running it when the motor was stock i didn't have the current issue i'm having now though it still might have been a little on the rich. today i had them order a 152 main.
i understand that could be close to what your running but you can't really compare since climent/elavation varie. take Honda400ex2003 for example..416 Stage 2 ,450r carb 168 main, 52 pilot
think i'll start with a 48pilot and 152 main and move the clip a position on the needle an see how that goes