Wide Open Throttle

[old grouch]

Quote from Jess Tolbirt:    "my bike runs like new except at wide open throttle,,,i can back off just a tad and zoom we are off to the races,,,punched baffles is all thats been done as far as i know,,,any ideas?" 
I too have this issue.  99 I/S, piggies cut & drilled, rear baffles only, 4* trigger wheel, K&N filter w/o prefilter, Pingle petcock, DanMark, no fuel filter.  Pulls strong up to about 90% throttle, then flattens out if I go beyond that point, but resumes pulling if I back off a little.  Based on what I have learned on this board, slow jets or pilot screw adjustment should have nothing to do with this issue,  but both have been done within the last 20K miles.  So what can be the cause?  All donations gratefully accepted.  Stan

[98valk]

u are lean on the main jets.

factory pro kit actually staggers the main jets and pilot jets.

http://www.factorypro.com/tech/carbtun.html

sometimes just shimming the front needles, richer than the other needles.

dial-a-jet is another option.

or use the OEM airfilter or use the pre-filter on the k&n which will also help reduce the amount of dirt your engine is ingesting.

[old grouch]

CA  Thanks for that.  This occurred with the OEM filter as well, but I will try putting the prefilter in (I saved it) & see if that helps.

[fudgie]

Could it be the trigger wheel? Thought it was good to mid range on power?

I have ECT mod, K&N w/ prefilter, pilots at 2 1/2, drilled rears with 3" of muffler hacked off, Pingel, fuel filter, NGK plugs, polished intakes, desmoged, and she pulls strong at least to a 100 mph. Plugs are great in color. Run E-10 when I can.

[Hoser]

Could you be bumping up against the rev limiter?  that would make it cut out. Happens really fast in 1st gear. Hoser

[R J]

Get rid of the lean end on top end.-------------------

It also might be a vacuum line leak.-----------------

Check em out and replace as needed.----------------

Really don't think the pre-filter has a damn thing to do with it.

I had that problem once, put pre-filter in, no different, took it out, and changed one vacuum line.   Went away.

Since I desmogged it and replaced those damn polished intake runners, those are rough for a reason, so leave em stock.     Cost me about 6 months of grief finding what I had done wrong.        I think I still have a nice set of POLISHED runners hanging on the shop wall.     Someday, I'll toss em in da sheet can.   Not yet, cause I still like to look at them and then cuss up a storm for my stupid foolishness.   

Used to do the polish on the race car, thought it worked, but now I have my doubts, and since I'm out of the circle burning, I have no way of proving it.

[old grouch]

Thanks all.
fudgie--I have the stock wheel, so maybe I will try changing it.
Hoser--I really haven't noticed any flat spot in any gears except 4th & 5th, not anywhere near red line.
RJ--Bike has been desmogged (by PO) so no vacuum lines, all the caps are new.  Can the lean be got rid of by changing the main jets or do you have to go to a whole different setup such as suggested by CA ExhaustCoatings?   Stan

[98valk]

Thanks all.
fudgie--I have the stock wheel, so maybe I will try changing it.
Hoser--I really haven't noticed any flat spot in any gears except 4th & 5th, not anywhere near red line.
RJ--Bike has been desmogged (by PO) so no vacuum lines, all the caps are new.  Can the lean be got rid of by changing the main jets or do you have to go to a whole different setup such as suggested by CA ExhaustCoatings?   Stan

stock airbox, no additonal holes? and stock exhaust as stated. u will not need to change the main jets. It sounds like u have a vacuum leak as mentioned, and I am leaning to a fuel delivery problem.  Is the danmark fully open? are any of the fuel bowls' vent lines clogged or not installed correctly? air vent lines should be run like a gravity drain line only up from the carbs. main concern would be any dips/trap where condensation could build stopping air movement. this would cause the bowls to run low fuel levels.

is the gas more than 10% ethanol?, that will make it run lean, but usually u would see leaness at all throttle settings esp. at idle.

[Rocketman]

If you are having trouble finding an air leak, and if that is indeed what the trouble is, I recommend that you check the boots where the carbs mount to the intake runners, and where the airbox mounts to the carbs.  Both of those are tricky to get on correctly, and the backside frequently doesn't get mated up correctly.

[BonS]

Quote from Jess Tolbirt:    "my bike runs like new except at wide open throttle,,,i can back off just a tad and zoom we are off to the races,,,punched baffles is all thats been done as far as i know,,,any ideas?"  
I too have this issue.  99 I/S, piggies cut & drilled, rear baffles only, 4* trigger wheel, K&N filter w/o prefilter, Pingle petcock, DanMark, no fuel filter.  Pulls strong up to about 90% throttle, then flattens out if I go beyond that point, but resumes pulling if I back off a little.  Based on what I have learned on this board, slow jets or pilot screw adjustment should have nothing to do with this issue,  but both have been done within the last 20K miles.  So what can be the cause?  All donations gratefully accepted.  Stan

How are you powering your DanMark? I powered mine directly from a coil wire and suffered high speed missing until I moved the power source off the coil. Only missed at full throttle.