high rpm miss

[randy]

1 inch = 25.4 mm

If you want to richen by adjusting the floats, with the carbs upside-down, lessen the distance between the gasket surface and the highest point of the float.

A good starting point is 25mm

If yours are now set to something over 26mm, you're going in the wrong direction, it's leaner than stock, plus the pod filters, yada yada whatever else was changed....

[edgo]

I went in the correct direction. I'm a good 1 mm under one inch now. I think a good petcock cleaning or rebuild will get enough gas to where it will run well.

Thanks,
Ed

[Winterhawk]

Sure the jetting's right? I've had similar problems with them using Motion Pro fuel lines and vacuum lines. The vacuum line will pulsate and suck in. The fuel lines will pinch easily. Make sure they are routed right and the correct length.

I could post some cool drawings with measurements and stuff later if you want.

Check your tank vent also.
I've had good luck putting the gas caps in the Ultrasonic.

[edgo]

I replaced the stock vacuume line and gas lines with heavy automotive hoses. I don't think they could collapse. I also got rid of the octopus setup. Something in there is restricting fuel flow.

Ed

[xj11john]

Ed,

let us know how it turns out.

[edgo]

I don't think that my gas tank cap is a problem. I had the tank off and I stood it up and gas came out. It isn't air tight.

Ed

[bandet01]

well i had a problem like that and it was electrical , the owner before me had wired the turn signals up and for some reason wired them hot at all times i and i had a miss a 6000 just like you and i redid and got new switchs and now it pulls out to redline in every gear so you might want to check you electrical on you bike it is a long shot but you never know

[edgo]

Bandet,

Did yours miss when it was in neutral, without any load on it?

Ed

[randy]

Edgo,

Have you checked your pickup coil wires?

[bandet01]

no because it would rev to redline in nutral but when riding it it wouldnt go over 6000 it acted like you just hit a brick wall and you would have to shift

[randy]

Still wouldn't rule out the pickup wires.

Load affects vacuum / vacuum affects timing plate rotation.

[edgo]

I set the timing yesterday and while I had the cover off I yanked on those pickup wires. I pulled them in every direction with some force and the idle didn't change. I think they are good. The bike has 20K miles on it.

Ed

[Winterhawk]

Make sure the Vacuum hose to the advance is open. I found one one time that had a little steel ball in it and it wouldn't advance.

If you have a dial indicator or other means to find TDC check the pointer and set it to TDC. Then check the timing and advanced timing.

[TopCatGr58]

Hey Edgo,

Okay, to recap: Larger main jets, floats to ~24mm, different coils with new wires, PU wires tested good, sure the gas cap vent is open, new fuel and vacuum hoses, removed Octy, cleaned petcocks. One thing I noticed is that you stated you removed the Pod Filters, but you also did a float adjustment at the same time, and then reported that the high speed miss was not as prevelant.

The wrong pod filters are notorious for causing a severe choking symptom and poor high rev performance!

Along with checking the pickup coil wires, have you inspected the vacuum advance unit, making sure the timing plate rotates when vacuum applied to the unit, and also are the centrifugal weights and timing plate rotating easily, not getting stuck?

Have you checked and verified that the bowl vent "T's" and hoses are unobstructed? What grade/octane of fuel are you using?

IS your battery fully charged! Have you checked the charging system to ensure it's charging properly at 4K rpm and above, at 14+ volts!?
T.C.

[edgo]

I got some bigger pod filters today. I did my own inhale test on the pod filters by breathing through them with my mouth. The bigger ones I got from MikeXS are much less restrictive. I did run the bike filterless and saw an improvement.

The bike has a new battery. I'll put a meter on the charging system this weekend and see what I get.

I think it is a fuel flow issue. I need to recheck the carb T's and the petcocks. I took the carbs and petcocks apart and cleaned them well. They look good but I think the petcock screens inside of the tank may need to be removed or replaced.

I set the timing by letting the bike idle at 1k and the marker lines up with the "F" when I hit it with the strobe. This whole vacume system is an unknown to me. I know it opens the slides by sucking them up but how do I test it? If the bike won't run above 6K rpms will the slides be all the way up? How do I test if the plate is rotating smoothly?

Thanks,
Ed