2007 3.0 Rattling/Timing

[dubs283]

I already put a bottle of octane booster in it before I even fired it up for the season

Oof! This is the last step in engine replacement troubleshooting, at this point you should contact your local marine repair/engine replacement specialist./s

 

[dubs283]

......

 

[Scott Danforth]

throw the octane boost away

set the timing properly with a timing light

 

[bjarnold1]

Well after setting the timing to 2 degrees ATDC and replacing the plugs and gapping them to the recommended .045 gap she runs perfect at all speeds now. Had to fine tune the idle air mix in between lean and rich stumble

 

[itsathepete]

Well after setting the timing to 2 degrees ATDC and replacing the plugs and gapping them to the recommended .045 gap she runs perfect at all speeds now. Had to fine tune the idle air mix in between lean and rich stumble

Glad to hear you its running well but it begs the question. Why 2 degrees atdc? Is your timing mark actually top dead center? You could have a spun balancer

 

[Scott Danforth]

Glad to hear you its running well but it begs the question. Why 2 degrees atdc? Is your timing mark actually top dead center? You could have a spun balancer

Because that is the timing speck for base timing mode

 

[bjarnold1]

When following the procedure for putting it in base timing mode I noticed it idled a lot rougher so I would assume it was in base timing mode. On that year the manual calls for 2 ATDC.

 

[Scott Danforth]

When following the procedure for putting it in base timing mode I noticed it idled a lot rougher so I would assume it was in base timing mode. On that year the manual calls for 2 ATDC.

Yes, in base timing, it will idle like crap.

once you pull it out of base timing mode, your timing will read somewhere between 8 and 12 BTDC

 

[dubs283]

Why 2 degrees atdc?

Spec, dude. Spec

I waxed on 2.5/3.0L motors in another thread. Not sure how to link it but the short answer is one of the greatest GM engines ever produced has gone through a few changes in it's 50+ year life span

 

[bjarnold1]

Right now the boat has 3/4 of a tank of fuel. I'm going to try and transfer the tank and get it down to around 1/2 and top off with fresh non-ethanol 91 octane to be on the safe side. I figured blended would be better than running what's in there straight

 

[bjarnold1]

I was able to get it down to 1/4 tank of gas and the old stuff didn't smell bad but was darker in color

 

[Rick Stephens]

Mixing bad fuel with good just makes more bad.

 

[bjarnold1]

I decided to get another gas can and siphon the rest of the tank out. As far as the filters go, I have one on the fuel pump and one on the carburetor. With as difficult as the one on the pump is to get to does that have a longer service interval?

 

[Rick Stephens]

I decided to get another gas can and siphon the rest of the tank out. As far as the filters go, I have one on the fuel pump and one on the carburetor. With as difficult as the one on the pump is to get to does that have a longer service interval?

Service interval should be annual, especially if there is any crud in the fuel at all.

If the one on the pump is hard to service, install an inline marine canister fuel/water separator before the pump and delete the filter on the pump. IF your fuel is always clean and the canister filter replaced annually, you can probably leave the one on the carburetor for several years.