Help Please

[Amo la terra]

I recently changed out my main, needle and pilot, I have some awesome torque however I can pin the throttle in neutral and the engine does not sound like it is even coming close to the 9100 rev limit, maybe I'm wrong but it doesn't sound right. Here is the changes that have been made:

07 400EX

165 Main (DynoJet)
40 pilot (K)
Needle on third slot from the top (DynoJet)
Air/Fuel 2 1/2 turns out
K&N Filter with Lid removed
Stock Exhaust

I though I was sucking too much air but adding the airbox lid doesn't seem to make a difference. I've also removed the stock spark arrestor (as a test) and other than sounding like crap it made no difference either.

Does anyone know of a cheap tach I can buy to check the RPMS on the engine? Or any other insights, I'm stumped.

Any help would be appreciated.

Thanks

[underpowered]

a 165 DJ main jet is WAY to rich for a stock bike. the reason it won't rev out is because it is getting to much fuel and canot burn it all. try putting the stock main back in and see if it will rev out then.

[Bill Fuller]

Are you sure your not hitting the rev limiter??

[Honda#4]

CRAP your rich!! Go down to a 150 or a 152 main and that should be a lot better, i'm suprised you weren't fouling plugs like crazy. You should'nt use anything over a 152 on a stock exhaust.

[Amo la terra]

Thanks for the replies.

I will try the 152 (K) that I replaced the stock 148 with. I just went by the instructions that came with the Jet kit. I guess I thought since the bike was pulling hard in 1st, 2nd and 3rd that the fuel mixture wasn't that far off.

Learning as I go.

Thanks

[Honda#4]

If you have any more problem just PM me and i'll help you out.

Removing the sparky doesnt affect jetting because it dont add much more flow. Removing the lid deals only with the needle.

[Honda#4]

on a stock pipe is does'nt do much maybe a tad bit but not noticeable but on a aftermarket pipe it does

Originally posted by Honda#4
on a stock pipe is does'nt do much maybe a tad bit but not noticeable but on a aftermarket pipe it does

Yeah on a stock pipe you have to mod the baffle for any real gain which is a simple mod. When I removed my sparky on my stocker only thing it did for me was helped me here what rpm i was at.

[Honda#4]

You get alittle bit more throttle response if you remove the sparky on a aftermarket pipe.

Originally posted by Honda#4
You get alittle bit more throttle response if you remove the sparky on a aftermarket pipe.

Sometimes more than that depending on how the sparky is made.

[Amo la terra]

OK,

Just so I have this straight.

If I'm running stock exhaust, 152 (K) Main, 40 (K) Pilot and a DynoJet needle on the third slot from the top with no airbox lid I should be close???

I am racing this bike, my main goal to to beat the banshee that is 1 point ahead of me in series points now going into the last race. I have beat him twice and ever since I started scr**ing with the jetting he has beaten me twice!

I have a good mind to set everything back to stock for the last race but I need to try and keep up with him in the straights.

Originally posted by Amo la terra
OK,

Just so I have this straight.

If I'm running stock exhaust, 152 (K) Main, 40 (K) Pilot and a DynoJet needle on the third slot from the top with no airbox lid I should be close???

I am racing this bike, my main goal to to beat the banshee that is 1 point ahead of me in series points now going into the last race. I have beat him twice and ever since I started scr**ing with the jetting he has beaten me twice!

I have a good mind to set everything back to stock for the last race but I need to try and keep up with him in the straights.

If you want to keep up in the streights you need to flow more air. The more the exhaust flows the more top end you have. But if your top speed is to slow you can only change that with rev boxes and sprockets.

[Honda#4]

152 main 40 pilot and the clip in the third or forth slot should be close, then you will have to dial in the air/fuel screw so it's right on. Good Luck on your race

[fullysic 400]

I too run a 2007 400ex.


Had no probs with the following done;

dynojet main 155
choke removed
stock pilot
airbox lid removed
K&n filter
needle 3rd groove from top
air/fuel mix at 3 1/2 turns out
sprockets 14/38 respectively
365ft above sea level
no bogging or popping on decel,plug colour ok.
goes from 0-105kph(top speed) bloody quick

[Amo la terra]

Here's my setup now,

155 DynoJet Main
40 Pilot
DynoJet needle, clip on third slot from the top
Fuel screw 2 1/2 turns out
K&N filter with airbox lid ON

I have attached my plug pic, let me know what you guys think
It runs through the gears much, MUCH faster and winds out nicely.

I don't know if I dare mess with it anymore but give your input anyway.

Thanks for all your help.

[Honda#4]

PERFECT!!

[Amo la terra]

Just for the record, I did end up setting the fuel screw to 3 1/4 turns out and the needle on the forth grove because the plug was a little white and the headers got as red as my plasitc :eek2:

I was only able to run it in the garage after the changes but the plug was alittle browner than in the pic but did not look too rich.

I'd rather been alittle on the rich side for the engines sake anyway.

I'm picking up a fresh plug tonight, anyone have any suggestions on plug type, other than one that fits?

:D

[Honda#4]

Just buy a NGK DPR8Z or 9Z them are the normal plugs for the 400ex.