rejetted,sputters up to 1/8throttle

[jasonwayne222]

I rejetted with a dynojet 155main, needle at the middle clip, no airbox lid,stage 2 cam 11:1piston 416, so it will sputter from idle to 1/8 throttle or maybe a little passed that, if u give it more throttle shes fine, this causes problems when puttin through the woods, ive got a 40main im gonna put in and see if it helps.

any thoughts

[honda400ex2003]

whats your f/a screw at? the rest sounds pretty nice. I would say with a 40 pilot go to about 2.5 turns out and you should be doing pretty good. just an opinion though. steve

[jasonwayne222]

i think the f/a screw is at 2 1/2 out but i dont remember, i rebuilt it two months ago and finally got to go ride today, but im gonna put in the bigger pilot tomorrow and see what the screw is at, im gonna also put the lid on to see if it gets better or worse, altho i love the power, it gets up to speed so much quicker i love it, i got a +3 key thats goin in next.

[honda400ex2003]

do you have a 165 or 155 dj. your sig is different from your post. just wondering. a 165 may be a bit on the rich side but it depends on where you are at. i would say that you should be ok with 2.5 but you could go to 2 and see how it runs with that. just an option for you, does it pop on deceleration? steve

[Strokin'400]

Hey take your spark plug out and read it, it'll tell you which way you have to go to get it in the sweet spot, sounds like it's running lean on the pilot go up a size see if that helps but plug chops are going to be your best friend. Do plug chops just let it gargle at 1/8th throttle on a cleaned plug, yank it read it jet it, then do the same for your mid range which will be your needle clean plug run it steady at mid throttle and kill it read plug, jet, then lastly main clean plug go wot clutch it coast in read plug jet the last jet. If your more then 3 turns on the pilot screw to get a change go to the next size up and readjust. Looking for nice tannish brown color on all jetting circuits. Just go around the yard for the slow ones and then open it up down the road for the last one. Hope this helps

[jasonwayne222]

i got a 155 in it now, i thought the 165 might have been a bit rich but it ran better with itso i will probly go up to a 160 and a 40 main tomorrow ill keep yall posted.

[honda400ex2003]

sounds good
i run a 170 keihin which is just a bit smaller than a 155 dj to give you an idea i am at 1500 ft about. steve

[jasonwayne222]

well i didnt get a chance to work on it yesterday but im gonna try to get to it today but i also wanted to add that it only does it once it is warmed up. it also has a small exhaust leak at the header flange and im pickin up some new crush gaskets today.

[honda400ex2003]

that might be causing your issue right there. do that first then see how it does. it may be letting some air in once the metal expands. steve

[jasonwayne222]

well i got like a quarter turn on one of the exhaust flange bolts and just a little bit on one of the others, but that wasnt it, i pulled the stock pilot to put in the 40 and found a couple of the small holes in it were clogged, put the new one in and its good to go, i let it warm up and rode it around the yard for about 20 minutes and the problem seems to be gone, also i pulled the plug and it was black, when i would give it full throttle real quick while just sitting i would notice a little black smoke so i put a 146 in and it seems to be better i also am at 2 1/4 turn out on the f/a screw

:) :) :D

[katch26]

alot of the times with these dual exhaust port heads you really need to turn them evenly....like take it apart and do it again. If its cocked like it sounds like yours could be than it will never sit flush. Thats how I do mine, its more time consuming but IMO its the better way to do it.

[jasonwayne222]

ya i get what ur saying and i know how to do simple things like that, the exhaust leak is because one of my studs broke off in the head and i dont really feal like takin the head off so i can remove the stud