hi
So i'm having a problem with my FXR super glide from 1989.
When i'm accelerating, with the weather cold or hot, and i get to 90 mph acceleration stops and i get no response from the throttle.
After the speed decreased to about 60 or 70 mph the acceleration comes back.
The performance is there i get to 90 mph really quick and i fell the healthiness of the engine but once it gets to 90 mph it just cuts off power and only comes back at 60 or 70 mph.

Al the help is welcomed.

Thanks,
Gonçalo

 

Sounds like you need a bigger main jet in your carb.
What carb and jets are you running now?

 

Need more information...is the bike stock? If so it was only 57 HP, so 90 sounds about right...

 

Yes, the Harley has the stock harley carburetor but has some drag pipes.

Because i have not open the carburetor i don´t know if the main jet and other components are stock.

But the situation is:
when i get to 90, i get there fast, the engine cuts off.
I kind of feel like if i were turning the Harley off and them when it gets to 60 or 70 it look like i turn the Harley back on again.
And this is systematic, no matter if the bike is really hot or if i just star riding it after some cooling off.

 

Sounds like it is starving for fuel at max throttle. I would check the float level, and check the petcock screen. It might be that you are "draining" the bowl and it cannot refill under high flow, but it can keep up under other conditions.

Just another possibility.

 

it doesn't sound like a fuel problem to me, it sounds like something in the electrical ignition circuit. does all electrical drop out......does the headlight go out too? if it does, replace the main circuit breaker.

 

EVOs hate drag pipes...motor looks untouched in the pic...stock carb...stock cam ...drag pipes ...90 mph...

Real exhaust, cam upgrade, and carb rejet will give you a major improvement...

 

Stock Ignition...has a rev limiter...and the first indication that a stock Box is on the way out is....Rev limiter malfunction...
1st what RPM is Max... 4the gear..
A simple switch to a Sportster Module will tell Volumes... higher Rev limit, and Quicker Advance... [ensure the VOES is functional]
If it had a Real Exhaust it will Perform Much Better also... But... won't Sound so ... Loud... only Iron Motors sound Cool with open Pipes!!!

 

I believe the headlight continues to work.
I actually don't need to be full throttle for this to happen, I can be cruising along and I get to a downhill when I get near that speed of 90 the Harley stops acceleration, eventually comes back.

Where can I buy these upgrades? 1-Real exhaust, 2-cam upgrade, 3-carb rejet

 

Can you explain me a little bit more what component that is? the location and what it looks like

Thanks so much for the help