what would cause my 86 to sputter at 50 + mph and almost die. I have to slow down and let it catch up - like out of gas. I have cleaned the filer, etc. - still have the issue.
When I fill up the tank - I do not have the issue (yet) - but there is still over 2 gallons in the tank.
I thought about taking off the carburetor to clean it - thoughts
is there any electrical issue that I need to be aware of?

Any help would be appreciated

 

Odds are a good carb cleaning, new needle valve, new seals and a careful setting of the float level will clear this up.

 

Gas cap vent plugged? Have you pulled the gas petcock and cleaned the strainer?

 

Just a thought, have you tried to pull the fuel line off to make sure there is sufficient flow"
Try a different set of plugs. Maybe one is breaking down.

 

Welcome to the site!

 

Battery fully charged?
Fresh fuel?
Fresh spark plugs?

When was the last time the intake seals were inspected/replaced?

It may also be that the float in your carb needs some attention.

My '98 has been sitting for a few years and its so bad that it won't even rev up.

I did this before and after replacing everything I thought it may have been and taking the carb off and apart THREE times, I "tweaked" the float and blew the airways out with compressed air and it ran like new.

If you can't remove and disassemble the carb take it to someone who can.

 

I remember the late 80s sportsters all having carb issues.
Never owned one but remember everyone complaining about it and asking advice.
You might want to think about going with a aftermarket carb like mikuni. Can't guarantee that it will solve your problem but that's what I'd do with it because of all the issues they had with them in the past. And the problem was when they were fairly new with low mileage.

 

Next time it does it loosen the fuel cap. I have seen this happen many times over the years due to plugged vent.

 

Only at high speed? Not at the same RPM at lower speed?

 

Pet **** & new filter!Clean tank out also fuel today not the best!