Mercruiser 470 fuel or carb issue...where to start?

[AeroNautical]

I picked up a 1986 Wellcraft American 192 with the Mercruiser 470 and Mercruiser outdrive. It was very well maintained its whole life, until recently, and I am hoping I got to it before it was too far gone. It was properly winterized before it sat for the last few seasons and when i drained all the fluids they all came out looking new. I have replaced the water impeller and new seals in the outdrive. New plugs, oil and filter, coolant at 50/50 mixture, distributor cap, rotor, points, condenser and coil.
When i went to start it i had good spark and engine turned over smootly. I can only get it to run for a few seconds on starter fluid and then it quits. I checked timing with a light gun in those few seconds and its where it should be.
I am looking for a recommended/logical place to start next with either fuel system or carb. I would prefer not to shotgun blast parts at it but rather narrow down to the specific issue and fix that. Any help would be appreciated.

Thanks!

 

[achris]

Hello AeroNautical, and :welcome: to iboats....

First thing, throw that can of starter fluid away! If you keep using it, you be replacing a head gasket, or worse....

If you must pour something down the carb, make it petrol, a small quantity....

Ok, with the spark arrestor off the carb, look down the throat and pump the throttle. You should see a nice healthy squirt of petrol. If you don't, then you either have a clogged up carb, or the fuel pump isn't pushing fuel through. Loosen the fuel inlet pipe at the carb (place plenty of rags under the pipe to catch nay dropped fuel, and keep the area well ventilated)... Crank the engine and see if fuel is coming up. If you are getting fuel up, pull the carb and give it a stripdown and clean out. No fuel? Then start looking at the fuel pump, and the supply to it...

Chris............

 

[AeroNautical]

Thank you! That sounds as good a plan as any. I'll definitely give that a shot first. I was wondering if there are any engine diagrams or parts locator for this model. I'm new to marine engines and would like to be able to locate/replace/install new filters and maybe a fuel/water separator.

Thanks again!

 

[Bt Doctur]

Standard fuel pump is mechanical so start at the tanks anti-syphon valve. Sometines they will stick/corrode closed shutting off the fuel.Again depending on how it was winterized the float and or needle and seat may be stuck closed. You can pre-fill the carb bowl .
do you have the merc manual for it?

 

[achris]

.... I was wondering if there are any engine diagrams or parts locator for this model.

Engine:
https://www.mercruiserparts.com/170-2-bbl-mercury-224-i-l4-1985-1986-1

Drive:
https://www.mercruiserparts.com/r-mr-alpha-one-sterndrive-1983-1990-1

Chris.......

 

[AeroNautical]

I pulled the fuel filter which sits with/on top of the fuel pump and it is bone dry. I am obviously not getting fuel out of the tank, which is about one quarter filled with fresh fuel. I checked the tank fill and vent line with my compressor and there is good laminar flow. I will have to research how to check the tank's anti-syphon valve because I am not familiar with that system.
I plan on getting a carb rebuild kit anyway so i will check all of those at that time. I did discover that my electric choke setting was set to about halfway open at all times, so I adjusted that to a normal closed setting. I am sure that was not the root of my problem but hopefully it will help.
I downloaded an engine manual offline, MerCruiser Service Manual 8. I will go tbrough that as well and see if it has any suggestions.

Thank you!

 

[AeroNautical]

Update.. I've pulled and replaced the fuel lines in and out of the tank to include the pick up and they were all clear. Old and dry rotted...but clear. I then took the fuel pump off and had to crack it open because it is rusted shut. I think I've found my fuel starvation issue! My question now is, do I rebuild it replace it or switch to electric? I may actually start a new thread on this so I can get some different view points. I'll take any advice I can get at this point.

Thanks!