3.0lx timing

[Potomacriverboater]

My mercuiser 3.0 lx engine will bog on take off then when it hits 3000rpms it will jump to 3700rpms. If the timing is adjusted to eliminate the bog it will ping on top end. What controls the automatic advancement of the timing?
Has anyone had this problem before?

 

[Don S]

Re: 3.0lx timing

What year is your engine and which distributor do you have?

 

[achris]

Re: 3.0lx timing

What ignition system do you have? There were, I think, 3 different systems... Best post the serial number of your engine...

Chris.....

 

[Potomacriverboater]

Re: 3.0lx timing

Mercruiser Alpa One 3.0 LX
Engine S# OF797676
Transom S# OF844067
Drive S# OF872134
Thats all the numbers I have. I do not know which distributer I have, it has two plugs on the side, one going to the coil and one power.

 

[Don S]

Re: 3.0lx timing

You have the Delco EST distributor, the advance is electronically controlled in the ignition module inside the distributor.
You also need to put the distributor into base tiiming mode in order to set the timing. You can not set the timing without that.

 

[Potomacriverboater]

Re: 3.0lx timing

Is base timing mode explained in the engine manual?

 

[Don S]

Re: 3.0lx timing

You can go to the link below to download the OEM service manual for your engine, then go to page 4B-25.
It explains how to put the engine into base timing mode for setting the timing.
http://www-alt.mercurymarine.com/mnetdata/SERVICE/CRUISER/Servmanl/13/13covr2.pdf

 

[achris]

Re: 3.0lx timing

1996, and an EST ignition system.... More Don's territory than mine.... He'll be back soon...

Chris.........

Edit: He beat me too it, again. (just kidding Don)

 

[Potomacriverboater]

Re: 3.0lx timing

Do you think that it is only a timing problem?

 

[JustJason]

Re: 3.0lx timing

Do you think that it is only a timing problem?

No

As always start with a compression test.
If compression checks out... then it sounds more like a tune up problem. Start with a full tune, All Fuel filters, plugs wires cap rotor, clean out your flame arrestor. An engine has to been in somewhat of a good tune to properly diagnose it. Start there, then report back.

 

[Potomacriverboater]

Re: 3.0lx timing

Thanks for the info but I have already checked compression and changed the cap, rotor, plugs, wires and coil, changed fuel filter and cleaned flame arrestor.

 

[JustJason]

Re: 3.0lx timing

sooo.... what were your actual compression numbers?

 

[Potomacriverboater]

Re: 3.0lx timing

135-139psi

 

[Don S]

Re: 3.0lx timing

Do you think that it is only a timing problem?

Since you have already done the compression test and a tuneup, why don't you set the timing properly, and see how it works after that.

 

[Potomacriverboater]

Re: 3.0lx timing

Found out the ignition module was for a car not a marine engine, installed new module and timed engine all problems gone.