i desperately need help with my 416!!

[rhandw69]

Recently i installed a Je piston, 416 kit.
This past weekend i took it to the sand dunes for the first time since the upgrade or downgrade!!
I have noticed a great increase of bottom end to mid. However from mid to top i virtually have none. In a 300 yard drag, i was getting past by scramblers, stock 400exs and anything else that tried. I could jump out on everybody by about 2-3 bike lengths. But once im there, i have no pulling power to top end speed.
Last year i was able to consistently beat the same bikes that are beating me now.
Who out there has a 416 that can ofer me some help on this, what is your carb settings at??
I left the cam stock as well as the carb, i do have a WB e series and K&N.
So where do i go from here???
Rhan

[nakomis0]

Sounds like you could use some jetting.

[rhino99]

Jetting sounds like the problem to me as well. I had a 300ex that I put a pipe on and the top end sucked. I finally jetted it right and the top end was 100 times better!

[NVR2L8]

Did you do any jetting changes after the motor work? What kind of jetting are you running now--pilot, needle, and main? Just as a starting point due to the increased displacement, I would think you would need a larger pilot jet, maybe lower the clip to richen up the midrange, as well as run a larger main. Of course, each setting depends on how the motor responds at the different throttle positions. Lastly, are you running quality unleaded premium that is at least 92 octane?

[rhandw69]

Well i had this buddy of mine working on my jetting so much that im not sure what im running now, i believe that i have a 148 pilot jet. A 162 main, and the clip in the last position to richen it up. All weekend long i was having a problem with it being really really lean. In fact dangerously lean. We turned my air/fuel mixture out 3 .5 turns.
Im beginning to think that i just need a bigger carb or something!!! Or a cam, because there is no way a bone stock 400ex should walk rite by me easily when 5 months ago, the same 400ex was basking in my sand roost by about 3-4 bike lengths. Needless to say it was a very frustrating weekend because of this. So i gave up on the 400 and rode the Banshee the rest of the time. Sorry!!
Rhan

[MJNOVA]

It sounds like something is amiss. For what your running a 50 Pilot and 162-165 should be OK maybe a little less depending on alt. If your still lean your sucking air somewhere or something is put together wrong. A 416 with a cam will ALWAYS outrun a stock bike.

[rhino99]

I think that you maybe have an air leak somewhere. You shouldnt need a bigger carb, just bigger jets to richen it up. I am not sure how you would go about checking for an air leak. Is your plug still lean? If so, HOW lean, is it real bad, or jut a little bit leaner than you would like?

I agree that a 416 shouldnt get beat by a stock bike under any circumstance besides rider error. Even without a cam you should stil be faster because you have a high compression piston. Actually, what compression are you running? Maybe you need race gas?

I'd get on the horn and call somebody that really knows what there doing before you need a new motor installed to fix the one that's soon to be blown up.. Call curtis sparks, tc racing, gt thunder, rocky ridge racing,,,somebody with the knowledge of what should be happening with that motor...Be smart and patiant with it,,,good luck..

[MJNOVA]

Just to clear things up: RACE FUEL does not give you horsepower. A basic rule that is most times true is: Use racing fuel for two reasons----A> If you increase comp. to the point that you are getting detonation--use a higher octane rated fuel. B>If you are trying to control engine temp. it is also a good idea. Race or High octane fuels burn slower and more controled, that's all in general. Most engines will produce more power on cheaper-lower octane fuels-----They may blow up, but lower octane fuels burn hotter... The way to use race fuel is to burn it and advance the ignition---Best of all worlds... If you go beyond 10.5 or so to one on a EX it's best to run it.

[rhino99]

I wasnt talking about using it to make HP, I just meant that maybe if he was running a high comp. piston, that not using it would cause it to heat up and not run as fast top end? I was told when I had my 300ex that excess heat sucked hp, so I thought that could be a problem?