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New 3.0 in older boat

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John4003

Regular Contributor
Okay I installed a new GM 3.0L in my 2001 Sea Ray 180 and everything is ready to go. It runs but I am a little unsure of where to set the timing. Do I go by the manual for the boat year or should I go by the Engine year?
 
I just set it to 1*btc. Seems to run good except just a little rough. Almost like a slight miss but maybe I'm being too sensitive since it's a brand new motor and I want it to purrr..
 
Use the timing specs provided by whoever sourced the engine for you, if you want to preserve the warranty .....the timing for a 'new' GM 3.0 should be about 19 deg BTDC at full advance (4000 RPM).

You would also be wise to follow the break-in procedure as well....
 
I bought it from Marine Engines.com and am following the break in instructions but they did not give me info on where the timing should be. I set it per the manual but want to make sure. Do you check the advance without the dist in base mode?
 
makomark said:
Use the timing specs provided by whoever sourced the engine for you, if you want to preserve the warranty .....the timing for a 'new' GM 3.0 should be about 19 deg BTDC at full advance (4000 RPM).

You would also be wise to follow the break-in procedure as well....
Click to expand...

Seems like it's missing no matter where I turn the dist. Just can't seem to make it run smooth.
 
Okay but I can't run it over 2k for the first hour. I cannot seem to make it run smooth neither which is weird. Brand new carb...
 
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Just pulled a couple plugs and they did have some black soot and also a small amount of oil which is probably just because the rings haven't seated yet.
 
If you are using the original 2001 ignition then use the 2001 proceedure and specs.

Regardless of new parts meaning replaced with new not a different ignition!!


What are YOUR manual specs ?

Share the procedure for your ignition and what and how you set the timing.
 
Ok following the manual, I let the engine warm up of course. I used a jumper wire on the two wires on the dist to bypass the advance. I also jumpered the shift interrupt wires and then adjusted the timing to 1*btc.
 
I just watched some vids and mine does not run as smooth as most. I have a vid of mine running but I can't upload it here.
 
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A couple of a couple if thoughts in addition to setting the timing to factory spec.

Intake to head or carb to intake vacum leak

are cap and rotor and plug wires in good condition!

said new carb new or rebuilt? Did you set idle speed and mixture on carb per tune up specs in manual, verify float level ? Choke fully open when warm? Try swapping old carb if it ran better

how long did it sit ? Is it possible that fuel is contaminated ?
 
Dieter said:
A couple of a couple if thoughts in addition to setting the timing to factory spec.

Intake to head or carb to intake vacum leak That's what I want to check out next. I followed all the specs for torque installing the manifold but not really sure how to check for leaks since there is no place to connect a vacuum gauge.

are cap and rotor and plug wires in good condition! Brand new.

said new carb new or rebuilt? Did you set idle speed and mixture on carb per tune up specs in manual, verify float level ? Choke fully open when warm? Try swapping old carb if it ran better New carb. It runs better with the new one but still runs pretty rough. I need to work on getting the idle set correctly.

how long did it sit ? Is it possible that fuel is contaminated ?
Click to expand...
New fuel, filter and anti siphon valve.
 
John, try using the P of E..... (process of elimination).
Check/test/replace one item and one item only at a time.
When used methodically and systematically, the P of E will not let you down!

Also..... if you have a concern, and if you want to go back through the cam follower adjustment procedure (aka valve adjustment or lifter adjustment), use the 4 stop static procedure. This places those two cam followers at the bottom of base circle.
The likelihood of making a mistake is nill if you use the 4 stop (4 cylinder engine)!

Start with #1 cylinder at TDC on the compression stroke.
Adjust both #1 cylinder intake and exhaust cam follower plunger depths as per OEM manual.

Rotate crankshaft 180* and adjust the #3 cylinder.

Rotate 180* again and adjust #4.

Rotate 180* again and adjust #2.

Done!



.
 
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Brand new engine so hopefully cam and lifters are good. I've replaced just about everything. I'm hoping it's just me missing something adjustment wise. One thing I did bad was before I installed the motor, I had a brain fart and turned it backwards about a qtr turn but I don't see where that would hurt anything.
 
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....................
John4003 said:
Brand new engine so hopefully cam and lifters are good. I've replaced just about everything. I'm hoping it's just me missing something adjustment wise.
That is precisely my point regarding the suggestion of the P of E.
If you perform the 4 stop, you will have eliminated that as a possibility.

One thing I did bad was before I installed the motor, I had a brain fart and turned it backwards about a qtr turn but I don't see where that would hurt anything.
No.... you did not hurt anything by doing that!
Click to expand...
 
Didn't think so. I think I need to go back and re-adjust the carb mixture screw and get the idle set and then re-time it.
 
John4003 said:
Didn't think so. I think I need to go back and re-adjust the carb mixture screw and get the idle set and then re-time it.
Click to expand...

After the boat is all together and run in, set up your base idle and mixture with the boat in the water, in gear and moving... Best proven way to set up the shake and bake.
 
Docksidemarineservices said:
After the boat is all together and run in, set up your base idle and mixture with the boat in the water, in gear and moving... Best proven way to set up the shake and bake.
Click to expand...

That's the plan. The manual says turn the mix screw out 1-1/8 turns to start but that seems really rich and the plugs showed some soot. I've been told it should be more like 3 turns. Thoughts?
 
The way to adjust IDLE MIXTURE is,

set main idle around spec, (650-750 rpm).

adjust idle mixture to achieve highest/smoothest results.

Once done, re-adjust main idle to spec. (final main idle adjustment is done in the water in gear at idle speed)

so the 1 1/8 is a starting point.
different engines/carbs idle mixture screw adjustment is all over the place........

Also confirm CHOKE is opening,

also many 4 cylinder engines can require several minutes to warm up so be patient.
 
John4003 said:
That's the plan. The manual says turn the mix screw out 1-1/8 turns to start but that seems really rich and the plugs showed some soot. I've been told it should be more like 3 turns. Thoughts?
Click to expand...

Temporarily install a vacuum gauge.
When adjusting the low speed mixture, shoot for the greatest vacuum reading.
You may need to simultaneously adjust the idle stop screw.

NOTE: the GM 3.0L in a Marine application is prone to what we call "run on" or "dieseling" upon shut down.
This is often caused by a lean air/fuel mixture and high cylinder temperature directly after a run.

You can address this later on!

The important aspect will be to see that this engine receives the correct ignition advance during the run-in period.
 
RicardoMarine said:
Temporarily install a vacuum gauge.
When adjusting the low speed mixture, shoot for the greatest vacuum reading.
You may need to simultaneously adjust the idle stop screw.

NOTE: the GM 3.0L in a Marine application is prone to what we call "run on" or "dieseling" upon shut down.
This is often caused by a lean air/fuel mixture and high cylinder temperature directly after a run.

You can address this later on!

The important aspect will be to see that this engine receives the correct ignition advance during the run-in period.
Click to expand...

I do have a vacuum gauge. I believe there is a plug on the side of manifold near the carb. Is that the best place to plug it in? Seems like the only place.
 
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