Whacky motor

PeterPalmieri · Post by **PeterPalmieri** » Sep 26th, '11, 13:25

The port motor starts right up and then stalls. I prime it and eventually get it to turn over and it runs fine but takes some work. Only happens when it sits for a few days or more. The starboard motor starts right up and runs no problem. most time needs no priming.

I believe I've read about this in another thread but can't find it. What's going on do I need to change the fuel filter? Is the fuel line slowly draining?

1985 454s.

In Memory Walter K · Post by **In Memory Walter K** » Sep 26th, '11, 14:14

Strikes me that there might be an air leak somewhere causing the fuel to drain back down to the tank on that engine. Check the tightness of your fuel filters and fuel line connections. Another possibility is a torn diaphragm on your fuel pump, but if she's pulling fuel back up on cranking, that's a lesser possibility. Is your automatic choke on that engine functioning properly? If it's mechanical, spray it with some of that CX you bought and move it back and forth to lube it. Let us know how you make out.

PeterPalmieri · Post by **PeterPalmieri** » Sep 26th, '11, 17:19

Walter was planning on taking your advice and headed to the boat on the way home. Of course it started right up. Will check everything as you suggest during the week c

Harry Babb · Post by **Harry Babb** » Sep 26th, '11, 19:28

Peter
Do you have electric fuel pumps or mechanical?.....1985 I am guessing mechanical....

If they are electric......are they the Carter pumps?

hb

PeterPalmieri · Post by **PeterPalmieri** » Sep 26th, '11, 19:46

Harry, I am embarrassed to say I don't know.

Harry Babb · Post by **Harry Babb** » Sep 26th, '11, 21:16

Peter,
I am pretty sure that in 85 they were still using mechanical pumps.

If they are mechanical the pump will be located on the front of the engine, on the right side looking from the flywheel end just above the oil pan.

I am with Walter, for some reason your fuel pump is loosing prime. It could be one of the check valves inside of the pump allowing fuel to drain back into the tank leaving the pump sort of dry.

Why don't you try turning fuel valve off at the tank at the end of each trip. If it is an internal problem with a check valve in the pump, turning off the fuel valve a the tank would prevent the fuel from running back into the tank while keeping fuel up inside of the fuel pump.

If the fuel pump diaphram has a small hole in it, and your pump is a marine pump (I think true marine pumps have double diaphram) , there should be some sort of collection bowl or line that would indicate fuel leaking out of the pump. If someone has replaced it with an automotive pump and the diaphram is leaking, fuel will be dripping into your bildge or draining back into your engine block.....you can tell this if your oil level is getting higher on the dipstick.

If you can prove that this is the problem then I would suggest that you replace the pump.....cause something ain't right.

I had a similar problem with my 454's with the electric pump...Carter's.....I replaced the pump and that fixed it.

hb

Carl · Post by **Carl** » Sep 27th, '11, 07:57

My Starboard motor has a similar issue. Mine need to be cranked for awhile till it starts..that is if it hasn't been run in a couple weeks or so. Once it catches all is good till it sits for an extended time.

My guess is the fuel pump. I'd change..but I like to let the engine crank a bit after a long sit to bring oil to the upper end anyway...have a spare fuel pump on board just in case.

A few seasons ago I was ready to change the pump out because I could not get fuel to Carb during Spring recommissioning...but then saw the pump was pumping...but then noticed the fuel line...even though Marine Alcohol rated turned hard and was not sealing at the fittings. Changed out to new fuel lines and I was good to go.

Long story short...make sure hoses are pliable, but NOT soft. Fittings are tight and seal.

Good Luck,
Carl

PeterPalmieri · Post by **PeterPalmieri** » Sep 27th, '11, 09:23

Thanks so much guys. I'll spend some time over the weekend and do everything short of turning off the fuel valve. Come back the following weekend and see how we do. If the problem persists I'll try shutting off the valve.

Makes sense?

Harry no noticeable change in the dipstick but I have noticed a slight increase in oil pressure from norm on that motor while running any chance the two issues are related?

Harry Babb · Post by **Harry Babb** » Sep 27th, '11, 21:50

Peter wrote:Harry no noticeable change in the dipstick but I have noticed a slight increase in oil pressure from norm on that motor while running any chance the two issues are related?

No....not really......I doubt that you are getting gas in the crankcase....really doubt that......just ignore that part.

My old Chaparell did the same thing.....but only after a winter of not running.

hb

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