3.0 Lx Sterndrive

[Scott06]

All looks like it's heading in the right direction. After you get the idle mixture screws and speed set in the water in drive, if you are fouling the plugs might check the fuel pressure is 4-7 psi. If it is more it can overcome the needle and seat and run rich. While it's sounds like your issue was intermittent, bear in mind that the 3.0 is not known as the smoothest running engine. Had one for 20 years, very reliable, just not smooth at idle

 

[jtomanelli]

OK so here's the sunny day update...

took the boat out with wife as my co-pilot and it started up immediately at the dock... unfortunately it smoked (black) for the first 2-3 minutes, then cleared up and sounded great at 1000-ish RPM to warm up. I suspect we have an issue with the choke, although I set it per the instructions to 1 deg CW.

OK so then the fun began, at the point where I put it under load it did nothing but backfire and wouldn't run clean above around 1000RPM!
I thought the morning was a bust, but I had the wife drive while I went to have a look and possible tweak...
MY BAD! I left the jumper wire on the timing advance wires!

Soooo after realizing and fixing my mistake it ran fairly "normal" thank goodness. I took the timing light and RPM meter with me and was able to set everything under load.
After that I had no engine issues at all... which is a first for the season! so THANK YOU to everyone on this forum.


Anyone have thoughts regarding the cold smoke problem?

 

[Rick Stephens]

Timing in base mode was hardly burning the fuel. Forget about it unless it comes back.

I set my choke so it barely is on at all. I set it by turning it (cold) until it has full choke, then I turn it back until the choke plate starts to open a bit. That's my starting point. Then I run it with a few cold starts and decide whether my motor is starting and warming up the way I want it to. If it seems to rich, I back off even more. (this is most often the case in my experience). If the motor seems hard to start with just a single throttle pump and leaving the throttle cracked open a little, then I richen it by closing the choke plate a teensy bit.

 

[jtomanelli]

good point Rick about the base timing at the dock... I'm hoping to get out again tomorrow with the kid this time and will see if I can tweak this choke in as well. Setting it to the "spec" angle seemed pretty tight to me, so I'll loosen it up a bit as you suggested.

 

[achris]

What's this thing 'choke' you refer to? I don't have one of those on my engine.

JT... Rick's method of setting the choke is spot on. Set to factory, then fine tune...

Glad you have a running engine, well done.

Chris. ..

 

[jtomanelli]

One last update on this topic... went out for a sunset fish with the boy, other than him beating me again, the boat ran perfectly.
Less smoke when cold at the dock but still not completely cleared up. I suspect I'll have to open the choke up just a little more. (Or at least make it a little sloppier)

Just for kicks I ran it at WOT for a couple of minutes and it sounded great. Ages ago it used to diesel a bit after shutting her down after a good run. This is no longer the case as I suspect the timing wasn't right in the past.

Anyways big thanks for all the help!

 

[Rick Stephens]

Glad to hear it! A good runnin boat, along with old whiskey, is one of the fine pleasures in life.

 

[achris]

A good runnin boat, along with old whiskey, is one of the fine pleasures in life.

:thumb:

 

[jtomanelli]

One more follow-up, because I'm a bit confused...

I took the kid out again this morning, and fishing was great by the way, but one thing that has me puzzled is the choke.

So I backed off the choke some more this morning just before starting (so it's cold) and it actually black-smoked for longer. Within 60-90 seconds it cleared up like before and we had a good 4 mile run on flat water.
Then on the return trip, only 2 hours later (I told you the fishing was good!), same thing but of course not as long.

My question is, is it possible I wasn't choking enough originally? Sadly, I can't tell you how much or how little choke was applied as I didn't take the flame arrestor off for this adjustment. Would too little choke produce black smoke?

Not a show-stopper, but kind of embarrassing at the dock

 

[Rick Stephens]

If in doubt, crank the choke all the way off. See what happens. The black smoke could be valve seals or guides worn. When not running, leaks a bit into the cylinders. Fire up and it burns off the oil. Maybe.... usually a whiter smoke than black tho.

 

[jtomanelli]

Ohhhhh I'm a real dummy! I just checked it in the driveway, this time with the arrestor off and of course it's still very tightly closed. I've adjusted it as previously suggested, slightly open to start.
We'll see what the results are.