My sled won't run past 9500 rpms at high boost, need help

[rxrider]

I have run into what I think is an ignition problem running the sled at high boost.

Please have a look in my 4stroke sled garage thread and give me your thoughts on a solution to my problem.

http://www.ty4stroke.com/viewtopic.php?p=644762#644762

Jan-Ove
rxrider

 

[Blue shadow]

one of the coil may be week ,i had the same problem last year .If you have a friend near by try the 4 stick coils from him and go from there .Put a new set of plugs in .I run my meth at 8 psi also and full at 20 psi on 22 psi presure with a/f at 11.8 .I used the stock plugs with no problems .She don t miss a beat from start to finish .How does your primary look when you move it up and down when it is apart ?

 

[powderlites]

9500 rpm miss

Gap plugs down to .020
Make sure no power robbed from ECU like hot grips or wideband A/F
Most times it's a power problem or bad recitifier/regulator.
http://www.powderlites.com

 

[jhlarsen]

maybe your meth pump draws to much amps and weekens the coils

 

[kinger]

Watts = V*A you got 40 watts to spare on the sled its a 12V system so you got 3.33 amps to spare

 

[rxrider]

Changed plugs to CR9Es gapped them to 0.020" or 0.5 millimeters. Connected the meth and ran the sled at 18+ lbs, sled ran great for 10 minutes then started to misfire at 9500 rpms.

Again I disconnected the meth and turned the boost down to 16 lbs, again the sled ran without misfireing at 10000-10200 rmps. AFRs was in the low 11s at WOT both on and off meth.

No current is drawn from the ignition circuitry as I have rewired all systems (wbo2, fuelpump and meth) directly to the battery thru a 30AMP fuse and two 30AMP relays.

Any suggestions?

I will start the tear down of my sled next week... could the problem be caused by a leak in the exhaust system aka cracked header? Will know soon if that's a problem....probably not as my sled runs hard off meth at 16 lbs of boost ????????

 

[Ted Jannetty]

Changed plugs to CR9Es gapped them to 0.020" or 0.5 millimeters. Connected the meth and ran the sled at 18+ lbs, sled ran great for 10 minutes then started to misfire at 9500 rpms.

Again I disconnected the meth and turned the boost down to 16 lbs, again the sled ran without misfireing at 10000-10200 rmps. AFRs was in the low 11s at WOT both on and off meth.

No current is drawn from the ignition circuitry as I have rewired all systems (wbo2, fuelpump and meth) directly to the battery thru a 30AMP fuse and two 30AMP relays.

Any suggestions?

I will start the tear down of my sled next week... could the problem be caused by a leak in the exhaust system aka cracked header? Will know soon if that's a problem....probably not as my sled runs hard off meth at 16 lbs of boost ????????

I believe this is exactly what I predicted would happen too much amp draw on the charging system from the meth pump, fuel pump, gauges etc.

The meth pump put you over the edge.

The ignition system needs 14 volts to run efficiently.

 

[kinger]

Would there be a way to test that without guessing? Voltage gauge on the sled and try to watch it at 9500 rpms?

 

[rxrider]

Any suggestions for a work around?

 

[Ted Jannetty]

Any suggestions for a work around?

Add an alternator????

Remove the meth pump and poor in race gas.

 

[kinger]

I found this pump on line that shows it draws 8 amps that is way overloading your 3.3amp you have to spare rxrider:

http://www.fjoracing.com/products/water ... /parts.php

Although there are guys running meth with no issue but not as high of boost either.

It is a good explanation of what yuor seeing. The way you have you have it wired it will draw off your battery while spraying and after 10 minutes or so your battery was drained enough and couldn't compensate anymore and then it was living just off the stator output and causing the mis fires to start up again.

What is the total amount of external electric devices you now have running on the sled?

 

[kinger]

Maybe you could disconnect your headlights, remove the taillight, un hook the grips, etc and that will over double the amount of amps available and see if that cures it. Although 'by the math' still not enough but I bet it would be close. Then at least you can isolate it to the draw and work towards a solution for that.

 

[HURRICANE]

Any suggestions for a work around?

Add an alternator????

Remove the meth pump and poor in race gas.

LOL.This is rediculous

 

[Ted Jannetty]

Any suggestions for a work around?

Add an alternator????

Remove the meth pump and poor in race gas.

LOL.This is rediculous

Unless you have a way to increase the output of the charging system, it is not so rediculous.

Simple Math.

The guys above have done the math on the amp load VS charging system amp output.

 

[rxrider]

Any suggestions for a work around?

Add an alternator????

Remove the meth pump and poor in race gas.

Thanks Ted, do you sell them?

The reason I run meth is to be able to run high boost on premium pump gas. Racefuel is hard to get. I'm up for a days drive back and forth to get hold of racefuels, and it's very pricey at $30USD a gallon. Removing the meth system is out of the question, and so is running racefuel.