Still Popping

[Newrider08]

Hey guys, I have an ongoing issue with my 2002 400ex. I had a popping on deceleration that started after I adjusted my valves, I figure it was lean since the valves were in spec it was getting more intake and needed more fuel.

I finally got around to checking what jets I had today and it had a 38 pilot jet, 148 main jet, and the needle was on the 3rd slot.


I put in a 40 pilot and 150 main and did not touch the needle, I turned my a/f screw out 2 1/4 turns then I had to turn it out a little more to smooth out the idle and it ran good.

I have a white brothers e-series and a uni foam filter. I am pretty sure it is on stock bore and it ran ok before but felt a little sluggish and crapped out in 4th and into 5th.

After jetting it the thing ran like it has never ran before but im still getting that darn popping on deceleration.

I checked my head pipe bolts and they are nice and tight, the only thing I found on the exhaust is a loose rivet on my white brothers e series.

any Ideas?

http://img25.imageshack.us/img25/2721/forum3c.jpg (http://img25.imageshack.us/my.php?image=forum3c.jpg)

[07350R]

How far above sealevel are you? I am at dead sealevel and I run a 155 main, airbox lid on, 38 pilot, fuel screw out 1 3/4 turns, baffle surgicly removed. My bike ripps and no pop on decel, just adjusted the valves last night. Usually pop on decelleration is a lean main jet.

[Newrider08]

I believe im at 800 feet and the temp today was about 60 degrees

[07350R]

I know Its a pain in the rear to keep pulling off the carb and keep trying different main jets but I would try a 155 and just see if it eliminates the problem, I know usually with jetting recommendations they recommend from zero to 1500 feet on sealevel jetting. May take care of the issue.

[Newrider08]

I can pick on up and try it, I have a 152 but nothing bigger than that laying around.

I noticed it was boggy in 4th and 5th before I rejetted today but I dont have any place around here long enough to run it in 4th or 5th to see if its still doing it

[honda400ex2003]

i see you dont have a quiet core but do have an e series, how many plates are you running. I am just curious cause mine makes a slight pop with different tips and I was thinking that it could make just enough of a pop to sound like a lean pop or something along the lines. Just a whim though, not to make you sound stupid or anything for not thinking about it. I am sure this is not it, just a thought while I am watching tv. I know I had told you to try to turn the f/a out a bit on your last one. still thinking about you now that I saw this I thought I would state waht I was thinking about. i figured it couldn't hurt to say it so here it is, anyone else have any experience with something like this? steve

[Newrider08]

its running 13 disks right now

[honda400ex2003]

OK sounds like quite a bit so it may not be it. do you have more or is that all that it comes with? Maybe more plates would let the air out further before it hits the end of the plates. there is a cover on the end right? It could be popping when it hits the plate. Are you following what I was talking about just out of curiousity? steve

[Newrider08]

Steve,

It came to me with 13 disks and I think that is pretty close to what comes with them total, I am going to do a plug chop on my next day off and go from there. I dont remember everything that I have been told Steve as this problem goes 5 different ways but if im missing something let me know, you seem to really get whats going on so I appreciate the help.

Thanks
Geoff

[Dathon Lawler]

i don't claim to be a carb guru, but my friend had a raptor doing the same thing. turned out to be the boot from the 'carb to the head' had a little gap in it, and was letting in too much air.