Merc straight 6 overhaul

I just had my 1967, 160 Hp, 250 Cu inch Mercruiser, Straight 6 Motor completely remanufactured. I usually do most of my own mechanical work but I figured this level of overhaul is beyond me. The mechanic did several additional cost things that were not included in the estimate. He told me my original Mechanical Advance only, Distributor, was worn out so he replaced it with one having Vacuum Advance. However, I notice, he didn't connect a Vacuum line to it. So it's only running with whatever mechanical advance the new distributor has.
It's a simple matter to add a Vac. fitting to the intake manifold. It seems to me that if the Distributor is made to operate with both Mech & Vac advance then I should connect the Vac line.
Any thoughts on the matter?
--------------------------------------------------------------------
I've found a few things which concern me: He replaced the Vibration Damper Pulley with a new thicker one (Because of the extra thickness there is now only about 1/8" clearance with the angle iron supporting the front motor mount. I will now have to pull the motor out in order to change the fan belt. Yes I bought an emergency adjustable belt. Don't think it's as good as a 1 piece belt). After he finished the Motor & was tuning it up. He changed several gauges including the engine oil pressure gauge & sender, which I had changed about 2 years ago, also at additional expense. They all had been working before the overhaul. He wanted to change another gauge which he said wasn't working right & he said there was a problem with the alternator. I decided he had done enough, paid for what had been done & took the boat home.
The motor started, but none of the gauges were working right & the batteries weren't being charged. I found a bad ground to the metal dash panel that holds the gauges & the wire going from the Voltage regulator to the battery was disconnected, took a while to find because it wasn't obvious that it was a wire going nowhere. I fixed the ground & connected the wire, everything works now.
I'll take it out for the 1st time next week. Hope he did a better job on the motor!

Re: Merc straight 6 overhaul

I thought the old A/C Delco distributors on the old Mercruisers were fixed--no mechanical advance. I could be wrong. I personally would have wanted to have been given the option to purchase a Mercruiser distributor replacement--instead of using a unit off an automobile. If it's supposed to have a vacuum, he should have put a vacuum line to it.

I don't know why he replaced the pulley. There again, a Mercruiser part would be preferable. You might want to pull the alternator and take it to an auto electric shop to have it tested. They're rebuildable for any good shop.

Sounds as if he got out of line. The straight 6 is a great engine for a boat--powerful enough and much smoother than my old 140 hp Mercruiser. Parts are still readily available for the older generation engines.

Re: Merc straight 6 overhaul

John3 said:

I just had my 1967, 160 Hp, 250 Cu inch Mercruiser, Straight 6 Motor completely remanufactured. I usually do most of my own mechanical work but I figured this level of overhaul is beyond me. The mechanic did several additional cost things that were not included in the estimate. He told me my original Mechanical Advance only, Distributor, was worn out so he replaced it with one having Vacuum Advance. However, I notice, he didn't connect a Vacuum line to it. So it's only running with whatever mechanical advance the new distributor has.
It's a simple matter to add a Vac. fitting to the intake manifold. It seems to me that if the Distributor is made to operate with both Mech & Vac advance then I should connect the Vac line.
Any thoughts on the matter?
--------------------------------------------------------------------
I

Click to expand...

Howdy,


A couple of things might concern me...... Did YOU tell him this engine is going into a boat?

The vacuum advance not only is NOT used on boats but it sounds like he used an automotive distributor. (NON-SAE J1171 compliant) It's also quite possible to change the mechanical advance springs on any distributor and eliminate the vacuum connection altogether. Vacuum is not used on boats because of the VERY low vacuum (high throttle) at normal cruising/running RPM

Unless it it an ignition protected distributor, (automotive distributors are usually NOT) you are at risk of an explosion.

You need to take the original vibration damper and have it rebuilt so you can use the correct belt on the engine. Yes, there's people who will rebuild your damper ( Damper Doctor Online - Your source for Harmonic Balancers, Motor Mounts, & Drive Shaft Supports )

I would not trust one of those "adjustable" belts on anything I own.....

If he (you) replaced the starter or alternator, You need to ensure that you're using marine compliant components (J1171)


Good luck,


Rick

Re: Merc straight 6 overhaul

Rick's right about those pieces. They need to be specific to marine use.

Re: Merc straight 6 overhaul

Hi Guys:

+1 on the above comments. I think you need to bring the engine back to factory specs and ignore your mechanic! Non marine parts are always a bad idea. Good luck.

kilowatts

Re: Merc straight 6 overhaul

Yep He knew it is from a boat, he only works on boats & he pulled & installed the motor. That's why I'm upset.
He claims he threw away the Vibration Damper. The only new ones I've found are too thick (1 3/16"). I'll try that "Damper Doctor" but even if I find the correct, thinner, Vibration Damper I'll have to pull the motor again just to install it.
I'm trying to figure out a way to jackup the front of the motor, the jack will have to be short & bear against the bottom of the hull. Then remove the steel angel iron the motor rests on & hope it doesn't damage the hull.
As far as the Alternator goes, it's still the original one, I didn't let him replace it, there was nothing wrong with it. I'll have to try & get more info on the Distributor.

Re: Merc straight 6 overhaul

John3 said:

Yep He knew it is from a boat, he only works on boats & he pulled & installed the motor.

Click to expand...

Another example of a "Boat" mechanic.

Yeah. I wasn't able to find a "new" damper form my 1955 Ford Y-block either. But people like the "Doctor" can rebuild any damper.

There are auto-electric places that can rebuild distributors too, including setting the mechanical advance curve to any spec required.