Symptoms of a bad mechanical fuel pump

[Big Chip]

I had a similar issue the other day but when it started to feel like it was stalling out I switched tanks and it would take off again. If I switched back to the original tank while cruising it would be ok for a while. After screwing around like that for a while I finally pulled over and looked at it. The filter was almost empty but then it would get a surge of fuel. It idled fine like that but didn't work under load. I have an electric pump and a hokey fuel routing and it was almost 100 out so I was thinking my problem was that the fuel was boiling off on it's way to the carb. I kind of ruled out the restricted line because when it cooled off it works as intended.

After I read this I don't know if you can get anything useful to help diagnose your problem but I'm not deleting. Never go backwards!!

 

[78C10BigTen]

Its messed up because today it ran the exact same way but the filter was full.... im confused other then thinking its spark...

 

[DoubleDingo]

Maybe there’s less to that hesitance to stay away from those filters than people think there is, but I’d rather be safe than sorry. I’ve heard of some people running plastic and glass filters for a very long time with no problems, but I’ve seen stories of people having them bust or leak out of the o rings on the glass ones and cause a fire. I cant speak from personal experience. All my filters have either lived in the carb or on the frame rail somewhere.

I was one that ran a glass one for years without problems. Now I am a metal canister and carb-filter guy.

 

[78C10BigTen]

I was one that ran a glass one for years without problems. No I am a metal canister and carb-filter guy.

I never had a glass one leak or cause fire but the fear of it i switched. Especially since ethanol eats rubber o-rings.

 

[bucket]

I ran a glass filter when I was younger. Then one cold morning, it started puking fuel everywhere. Haven't run one since. But I have run a bunch of those plastic filters without any failure. They are always mounted above the intake and in a way that doesn't cause them to vibrate.

The problem sounds like it could be fuel or spark. What do the plugs look like?