450R Carb Richening Suggestions

[3or4HONDA]

Took the ex out for a ride today, being the only second time i have rode it with the new carb and it ran great. MUCH better than stock. Only a few issues that i need some help on....

these are the specs....
416, Hotcams Stage 2 K&N No lid
190 main, 52 pilot, 2 3/4 turns out on f/a, clip in the middle
this was suggested after dyno tuning on a very similar motor at very similar elevation.

i checked the spark plug when i got done riding and it is whiter than i want on a fresh motor, also it pops a little on decel but nothing terrible. other than that pulls hard through entire rpm range with no dead spots, so im wondering...

whats the best way to richen the carb up BUT not so much that it will dog.

f/a?
go to 195 on the main?
needle position?

thanks
Adam

[jcs003]

"it pops a little on decel" if this is so, you might have detonation. what is your compression ratio? the pop could also be a very tight valve. when engine rpm slows this happens which could be a tight valve.

[3or4HONDA]

im running 11:1 on 93, so could it still be detoantion? i dont really know what that sounds like. but the plug is white too, so i know its at least a little lean....and that would cause it to pop

thanks for the response

[hypersnyper6947]

Considering the plug is white, i would say the poping on decel is because your to lean not detonation. Try to move the clip on the needle one notch down, so if your 3rd from the top move it to 4th from the top, that should make it a bit more rich. You dont want to be lean thats for sure.

[hypersnyper6947]

Im not sure what your elevation is compared to mine but this is what im running 48 pilot needle on the 4th notch from the top, and a 178 main. my mods are in my sig, hope this helps

[3or4HONDA]

thanks hyper i will try the needle, my elavation is around 1000ft above sea level.

[jcs003]

with ethenol in winter season fuel it is common for fuel ratings to be inconsistent. detenation is possible. also, a lean condition and detonation have similiar symptoms. hopefully just a minor jetting issue.

[rideracelivemx7]

holy chit, 190 main and 52 pilot!? on an ex! hot dang, my portpolish 11:1 crf450r only got 185 main and 48 pilot. and thats a hell of a lot more motor ill tell you that much! mabe i should try your numbers, just cant get it to run quite right, stalls easy and pops lately

[3or4HONDA]

well i dropped the needle to the 4th clip and it is still popping, any other suggestions.

plug is black around the edge but the electrode is pretty white.

thanks

[bbender85]

sounds like you're still lean on the pilot. i rode too for the second time on my 450 carb last weekend, and i had trouble starting it cold without the choke and also had popping on decel; i am running a 52 as well, 2 1/2 turns out. i tried to start it yesterday when it was 70* outside and it pretty much fired right up... so i am real close. going to bump to a 54 and see what it does.

how similar does your plug look to this (don't mind the dirt!):

http://i154.photobucket.com/albums/s248/bbender85/quad/DSC05053.jpg

i am running the exact same setup you are, but 426 and a 195 main. i am curious how far off i am.. i posted my own thread without a ton of responses.

[3or4HONDA]

ya i havnt had much luck with responses either, but a couple helpful ones. mine looks pretty close to your plug and i dont think it is terrible but i just dont wasnt the backfire, does your pop on decel? if it does let me know what the 54 pilot does....


ya and mine is kinda a pain in the cold but the other day it didnt take much to fire up and stay running.

[BigLuke]

I went from a 190 (plug was white and ashy looking) to a 210 and a 52 pilot 3rd notch on the needle and 3 turns on the a/f and it runs awesome with a good color on the plug. My mods are listed below and Im running 50/50 93 and 110 race gas.

[zrpilot]

Guys,

Reading plugs with today's gas is VERY hard.

The area you are interested in is all the way up inside the plug where the sun don't shine. This area is colored when all is wide open under full power because the combustion chamber heat totally cleans off the other of the porcelain. It will take a special plug reading flashlight with the magnifying glass to view it correctly. Plugs cannot be correctly read by just quickly looking at them with the naked eye.

[3or4HONDA]

Thanks ZR,

so what do you suggest?

bump up the pilot to get rid of the pop?


it runs fine everywhere, so do you think the main is fine then?


the plug cannot be completely useless is getting the jetting correct....

[zrpilot]

Originally posted by 3or4HONDA
Thanks ZR,

so what do you suggest?

bump up the pilot to get rid of the pop?


it runs fine everywhere, so do you think the main is fine then?


the plug cannot be completely useless is getting the jetting correct....

Move the clip down one notch on the needle. A little popping on deccel is not neccesarily bad... as long as it is not too severe.

Also if you can check the air cut off diaphram to see if it has any cracks or leaks vaccuum.

Zrpilot

[3or4HONDA]

Thanks,

ya i dropped the needle from the 3rd to fourth and i didnt really notice a difference. i took the diaphram apart before i put the carb in and it was in good shape.

im prolly just a little paranoid on the jetting since the motor is fresh and i dont want to do any damage to it.

[3or4HONDA]

i think this weekend i will try a 195 main and 54 pilot with the needle back in the middle and see what that does.

[zrpilot]

Originally posted by 3or4HONDA
i think this weekend i will try a 195 main and 54 pilot with the needle back in the middle and see what that does.
try that. Is it cold there? IF so then you may need towiat until the temps warm up and get serious about jetting. I really don't trust reading plugs. Here is how I reccomend doing it.

Pilot screw: Turn screw in GENTLY until it bottoms. Turn out 1/4 turn at a time until smooth idle is obtained. Normally do not turn the pilot screw out more than 2.5 turns. If you must turn it out more than 2.5 turns go up to the next larger pilot screw.

Pilot jet :The pilot/slow jet will eliminate or reduce popping that occurs when letting off wide open throttle. The pilot/slow jet will also improve cold weather starts. Go up 1 pilot/slow jet at a time, don't skip sizes. After installing a larger pilot/slow jet, re-adjust the pilot screw.

Main jet: Start with the biggest numbered main jet and run at wide open throttle, the engine should stumble at wide open throttle. Install the next smaller size until the stumble is gone. Once the main jet is correct re-adjust the pilot screw first and the pilot(or slow) jet if needed until proper idle is obtained.

[3or4HONDA]

Thanks ZR,

ya it is pretty cold yet, one day it got up around 60 but so far its been been hovering in the 40's.

[3or4HONDA]

i think i got it, went with a 195 main and 55 pilot and got rid of the pop on decel and it starts much better in the cold. plug still looks pretty white but im gonna leave it, im running a 9z instead of the 8z so maybe that has something to do with it.