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c.2000 Mercury 135-HP Suddenly Stops

Posted: Sun Oct 22, 2017 1:49 am
by Scarab
I have a 2000 Mercury 135-HP outboard enginel with 118-hours of operating time. Just yesterday, while running at 4,000-RPM at 45-MPH, the engine suddenly stopped. When started again it stalled at low RPM when in gear and couldn't get on the boat to accelerate to plane.

Due to the fact that I heard a weird non-metallic noise, I poured oil into the [fuel tank] and checked the fuel lines. The noise stopped and the engine performs well at high speeds, however it still stalls when in gear to plane. [The cause of the stalling] has to be something with the fuel and the fuel pump. [Give me] ideas.

Re: c.2000 Mercury 135-HP Suddenly Stops

Posted: Sun Oct 22, 2017 12:45 pm
by jimh
As a general rule, if an engine that is running normally and then immediately and suddenly stops, the cause will tend to be electrical. If the cause were due to a fuel restriction, the engine would tend to lose speed more gradually as the fuel in each cylinder's fuel source began to run out.

What sort of c.2000 Mercury 135-HP engine are we discussing? Give more details about the engine and the method of fuel induction.

Is this engine an OptiMax model?

I don't think that adding some two-cycle-engine oil to the fuel tank would cause an immediate cessation of any noise. The new fuel-oil mixture would tank a minute or two to flow into the engine and become the fuel being introduced into the cylinders.

Re: c.2000 Mercury 135-HP Suddenly Stops

Posted: Sun Oct 22, 2017 2:59 pm
by Scarab
This is a V6 135hp ELPTO with s/n OG913805.

Re: c.2000 Mercury 135-HP Suddenly Stops

Posted: Sun Oct 22, 2017 3:43 pm
by Scarab
On second thought: I might have run the engine [with the battery switch in the] BOTH setting. Would that cause this result?

What should I do now?

Re: c.2000 Mercury 135-HP Suddenly Stops

Posted: Sun Oct 22, 2017 5:47 pm
by jimh
Do you have the factory SERVICE MANUAL for this engine? If not, getting the manual is the first step in doing your own service on the engine. Generally a factory service manual will have some diagnostic advice.

Re: c.2000 Mercury 135-HP Suddenly Stops

Posted: Sun Oct 22, 2017 7:33 pm
by Don SSDD
Scarab wrote:On second thought: I might have run the engine [with the battery switch in the] BOTH setting. Would that cause this result?

What should I do now?


The battery switch in both would not effect engine operation.

Re: c.2000 Mercury 135-HP Suddenly Stops

Posted: Sat Jan 06, 2018 4:54 am
by Scarab
Just for the record, after checking the engine, the problem was that one cylinder stopped working when the engine stopped at WOT. When I restarted and added extra oil into the fuel tank, the engine was running with the remaining five cylinders.

When I checked the compression in {the non-working] cylinder it was 0-PSI.

A mechanic told me that half of the engine has 125-PSI compression and the other half 110-PSI. The sixth cylinder has no compression at all.

The probable cause: the oil injection not running correctly.

Thanks again. All the best for a Happy and Healthy 2018!