92 55hp commercial fuel pump question

[Fletch_n]

G'day all

I have a quick question for you all, if you disconnect one of the fuel pump to carb lines how much and how often should it pump out? I have an issue where this motor won't idle off the choke, I have searched here and all recommendations were to rebuild the carbs, which I have done, stripped and cleaned, and a kit through both, set up timing etc as per book, but it won't idle off the choke? I can get it to idle if I wind the idle mixture screws out about 4-5 turns but it it crap. Choke pulled out idles okay, pulled the carbs apart again, all good, still no idle off choke. Pulled pump to carb line and it gives a little squirt once with a good pull of the starting rope, is that enough? I am at a loss otherwise?

Cheers

 

[Fletch_n]

Re: 92 55hp commercial fuel pump question

Arggghh! This motor is starting to do my head in! I have stripped and cleaned the carbs 3 times now, and double checked each rebuild, but it still won't idle with out the choke? It starts 1-2 pulls on choke and runs okay, warms up no probs but and soon as the choke is pushed in it dies. I have also pulled the choke line off while its running and it dies the same way. It's not getting any fuel through the idle system, I've checked all the jets and orrifaces and check all the gaskets aren't blocking anything, all the passages are clear (3 rebuilds have confirmed that!) now I'm at my whits end, have ordered fuel pump rebuild kit as I'm wondering if the pressure isn't enough to push up to the top of the carb for the idle circut?

Other than that has any one got any advice what the heck could be causing this? Has new plugs, good even compression, clean new fuel, clean filter, new thermostat.

Cheers

 

[kodibass]

Re: 92 55hp commercial fuel pump question

start the motor, then pull the fuel pump to carb line off at the carb, there should be with the motor running a fairly constant pulsing of fuel coming out of the hose. check all connections & hoses for leaks tears etc. borrow an tank & hose from a known good running rig,

 

[Fletch_n]

Re: 92 55hp commercial fuel pump question

Thanks kodibass, i have been through all the fuel lines and blown them all out and inspected them all, ill have another check, I have a second tank so ill try that one, otherwise after the fuel pump is rebuilt I think it might have beaten me if that doesn't solve it, I just can't for the life of me figure out why the idle circuit isn't getting fuel!

 

[Fletch_n]

Re: 92 55hp commercial fuel pump question

Quick update for anyone with later model carbs with the fine thread idle screws, initial setting of 1 1/2 turns out from lightly seated is no where near enough I say 3 1/2 out from lightly seated is a good starting point! This was my idle fuel starving problem, feel a bit stupid for not thinking more about it when it ran at 5 plus out due to me forgetting to set it but you get that.