[engenheirobr]

Hi Guys,
I have a 1982 CX 500 turbo with 6000 original miles and it was running perfect but last month it had a kinda backfire and now it starts to misfire or cutting off when the engine gets very close to full booster. The turbo is working fine and the motorcycle has normal acceleration and performance until gets close to the full booster.
I checked for any connections lose, any vacuo leaks, but everything is fine.
I checked the electronic computer but does not have any led on. All off and fine.
It has new battery, new spark plugs with correct gaps, no oil leaks, no corrosion in any ground.
I use just 92 ethanol free gasoline available from a gas station close to my place in Houston.
Everything works perfect. It start fine, drives fine but I can get close to full booster.
What could it be?

 

[engenheirobr]

Sounds to me a fuel starvation problem. So a bad fuel pump or a clogged fuel filter

I think you are right. The fuel filter is brand new but I had the fuel shutoff valve rebuilt because was leaking. Maybe the valve is not letting pass enough fuel from the tank to the pump. I will check that later and come back to you with the result.