This boat… always something…popping today

[River Pete]

Hey all -
2000 Monterey with 5.0 GL-C

Last summer - new ignition coil, rebuilt carb, new fuel lines, new pump relay new filter. Ran great and had a nice end to the summer months without issues.
Winterized it and have been running it for the last two months without much of an issue (minus the prop shaft seal…)

I have a question re: performance. A few things the last few runs.
-a small amount of white smoke only at idle out of the exhaust. A fuel smell.
- a bit of a hard start when warm, sometimes it takes a little extra throttle.
- today noticed a new fun little thing when under initial hard load and accelerating, nice little popping sound and loss of power. When low rpm and minimal load, no problem. At speed and rpm’s up around 3000 and cruising - no problem. Not even a consistent popping with load, just intermittent. Occurs when engine is warm and cool.

I have a few things in mind to look at but would like some input in case I am missing some marbles in my head.

 

[Donald0039]

It sounds like ignition. But first I would dump the fuel from fuel filter into a clean mayo jar and see if it looks like clean fuel or do you see water or other contaminants.

Then go through the ignition. Look at plugs, wires, distributor cap and rotor.

 

[River Pete]

It sounds like ignition. But first I would dump the fuel from fuel filter into a clean mayo jar and see if it looks like clean fuel or do you see water or other contaminants.

Then go through the ignition. Look at plugs, wires, distributor cap and rotor.

Yes sir that was on the list.

 

[cyclops222]

Definite POPPING sounds pretty steady ? I vote for lack of fuel at the higher power and flow rate needed. Could even be a change in the timing at higher rpms........Does the popping sound also happen in NEUTRAL and high rpms ?
I noticed you did not say you changed the sparkplugs. Did they all look perfect ?

 

[flashback]

check your fuel for water.

 

[River Pete]

Definite POPPING sounds pretty steady ? I vote for lack of fuel at the higher power and flow rate needed. Could even be a change in the timing at higher rpms........Does the popping sound also happen in NEUTRAL and high rpms ?
I noticed you did not say you changed the sparkplugs. Did they all look perfect ?

Not steady, intermittent and sporadic under load through the day.
Plugs pulled a month ago and looked fantastic.
Does NOT happen in neutral with revved engine.

Was thinking go about the water in gas. Seems very plausible as I just added a new dump last week.

Gonna check over all the ignition stuff tomorrow - happy 4th to me…

 

[cyclops222]

Started after buying the last load of gas ? Bingo All the first big refilling of the stations big tanks bottom with water & crud.

 

[River Pete]

Started after buying the last load of gas ? Bingo All the first big refilling of the stations big tanks bottom with water & crud.

I hear ya. Man I sure hope it’s that simple… but with my luck?….

 

[cyclops222]

I will often ask the gas dock person........When was the last gasoline delivery made at your place ? I wait 2 days if needed.

 

[Donald0039]

Sounds like the place selling gas has an issue. I would notify them. Was the gas E10? If phase separation occurred the only solution is to pump out the old gasoline, flush the fuel lines and refill with fresh gas.

If it's E10 it has up to 10% alcohol and that will absorb some water and that mixture will flow through the fuel filter and be burned. If there is more water than can be absorbed by the alcohol in E10 gas you have problems. Like phase separation.

Dump the fuel filter into glass jar to examine.

 

[River Pete]

Well, I guess it was just water in the gas. With my luck, this is hard to believe but so far no other episodes have shown up like that one so …. I guess it was a win?

We buy nonethanol and bring it to the boat by jugs. It’s just easier since the boat is kept at the lot by the river.