air bubbles in fuel line

[mike1245]

i get air bubbles in fuel line and have to run motor with choke on to get it to idle also noticed the bubbles are between the pump and carbs with choke on they travel to carbs and with choke off the seem to travel to the pump(backwards) does this mean my pump is bad? also noticed i have a small leak at carbs somewhere too looking for that first just need to know if i need pump rebuilt.

 

[achris]

Re: air bubbles in fuel line

You may have a perforated diaphragm in the fuel pump... The fuel system needs to be 'tight' or it will suck air (before the fuel pump) or leak fuel after the fuel pump. Neither of which are good.

Chris.......

 

[mike1245]

Re: air bubbles in fuel line

took off fuel pump and found it to be badly rusted ordered new pump with gaskets should be here monday

 

[mike1245]

Re: air bubbles in fuel line

got new fuel pump installed and runs better now have ticking sound (like spark plug wire grounding out) and motor idles rough and quits

 

[achris]

Re: air bubbles in fuel line

Start from scratch.. Do a full tune up. Compression test, new spark plugs, check timing and carb sync, THEN check fuel mixtures and idle speed adjustments.

Chris..

As yet we have no info on your engine... What are we dealing with? Hp/year/serial number....

 

[mike1245]

Re: air bubbles in fuel line

i have a 1973 mercury 500 i have replaced internal wire herness due to bed wires and splices eveywhere. cap, rotor, and wires. compression is 100 to 110 on all 4 cylinders. dont think its timming because it does it intermitenly does it for about 2 min the stops for about 10 seconds then does it agian and dies out but will check timing tonight

 

[mike1245]

Re: air bubbles in fuel line

wtf started boat up after work today and did as befor then after about 30 minutes of starting and stopping it just quits and now runs perfect but we shall see what tomorrow brings

 

[mike1245]

Re: air bubbles in fuel line

well its been running great for about a week now so yay me