89 Cris Craft 4.3 GM tune up

[Svshaw82]

Hey guys, just had a few queations. Looking to do a tune up on our 17' bow rider. It has a GM 4.3L V6. Where can I find parts for it? Looking to do the basics, plugs, wires, cap, rotor, oil change.

What do you recommend for oil, plugs, etc?

Thanks in advance for any help!

 

[Lou C]

Oil you will get all kinds of recommendations, I myself like the Merc/Quicksilver 25-40 because it is really blended for marine inboards and readily available. If you can't find this you can use straight 30 or 40 or even a 15w/40. Plugs, the standard GM Marine plugs work best in these engines. Cap, rotor, are Prestolite items, you can get them from an Evinrude dealer or any marine store that can order Sierra parts. Keep in mind unless the distributor was replaced you probably have a Prestolite points distributor with centrifugal spark advance.

 

[Svshaw82]

I read somewhere that any diesel oil would work good. Was tempted to drop in some 10w-30 Rotella, since it's what I use in my jeep.

Could I get the plugs cap, rotor, and wires at Oreillys? That would save me a ton over a marine store that would have to "order" everything.

 

[Svshaw82]

The engine is all stock from what I can see. I would assume the distributor is the same.

 

[Svshaw82]

Also i don't know if it's ever had a decent tune up, the wires look old, maybe original.

 

[Lou C]

You won't find those at O'Reilly's because they are marine specific. You can't use auto spec parts in your marine distributor and auto parts stores usually don't sell marine spark plugs either. If you have a NAPA auto parts they can get marine parts, you might try that first. I like OE parts if I can get them for ignition. Sierra is OK but OE is better. If you want to do internet shopping try Crowley Marine. They sell OE OMC parts on line.

As far as oil keep in mind that your marine engine will be running at about 3500 rpm constantly when you are up on plane at cruising speed. Marine engines run under load all the time, there are no gears or overdrive in marine transmissions. So a heavier weight oil is what most use. Either straight 30 or 40, the Merc/Quicksilver 25-40 are top choices to me. Anything else, is something that people use, but the companies that adapt auto engines to boats (Merc and Volvo) do not advise you use. They recommend the ones I listed and for Volvo a syn 10w40, not mineral because it will break down in marine use.

 

[Redrig]

right here on iboats , will have everything you need

 

[Svshaw82]

Need parts faster then shipping was just hoping I didn't order tune up parts

 

[Bondo]

Ayuh,.... I guess that's a problem,....

Cars don't use marine ignition systems, 'n automotive plug wires are shorter, usually with the wrong ends, compared to marine spark plug wires,...

 

[Svshaw82]

Found some Quicksilver 25w-40 4 stroke oil and my filter Fram 3980 at walmart of all places.. lol!
Cross checked my spark plugs i pulled from the motor and was able to source similar spec Autolite 26 plugs.

 

[Svshaw82]

Guess the wires will have to stay for now, cap and rotor upon inspection seem ok. Suppose they can stay as well for now.

Is there any problem upgrading the ignition coil to a MSD Blaster? It looks like a standard coil that's installed now.

 

[Lou C]

Find an Evinrude dealer and they can get you all the parts needed, except for the ones that are NLA. For that go with Sierra. Standard coil is fine no need to change it. The Prestolite distributor is very simple, easy to service. If you want to convert to electronic, it is possible but you have to replace the ESA module with one that will work with the electronic dist. All ignition and fuel components (carb, fuel pump, distributor, alternator, starter) must be marine rated for safety. This is no joke, fuel and sparks in the bilge of an inboard can blow you into the next world. Do not cheap out on anything ignition, electrical or fuel system related on any inboard, no matter how cheap the boat was to buy. Also since we are talking safety make sure your bilge blower works and you use it properly and ALWAYS have the backfire flame arrestor in place when you start the engine.

 

[Svshaw82]

Find an Evinrude dealer and they can get you all the parts needed, except for the ones that are NLA. For that go with Sierra. Standard coil is fine no need to change it. The Prestolite distributor is very simple, easy to service. If you want to convert to electronic, it is possible but you have to replace the ESA module with one that will work with the electronic dist. All ignition and fuel components (carb, fuel pump, distributor, alternator, starter) must be marine rated for safety. This is no joke, fuel and sparks in the bilge of an inboard can blow you into the next world. Do not cheap out on anything ignition, electrical or fuel system related on any inboard, no matter how cheap the boat was to buy. Also since we are talking safety make sure your bilge blower works and you use it properly and ALWAYS have the backfire flame arrestor in place when you start the engine.

Yes, it's definitely on my mind. I had to fix the blower, fan came dislocated from the motor. And it has a flame arrestor on the carb. I also installed a fuel check valve. Ordered a Carter Marine electric fuel pump yesterday too. Seems my mechanical has a bad diaphragm, blowing bubbles with the fuel unless I pinch the vent line.

Going electric because with the boat sitting often the carb bowl evaporates the fuel, making it a pita to start. Hoping electric pump helps solve the hard starts.

 

[Svshaw82]

On a side note with just the oil change and new plugs it runs a lot smoother. Fires right up without hesitation.

 

[Svshaw82]

Find an Evinrude dealer and they can get you all the parts needed, except for the ones that are NLA. For that go with Sierra. Standard coil is fine no need to change it. The Prestolite distributor is very simple, easy to service. If you want to convert to electronic, it is possible but you have to replace the ESA module with one that will work with the electronic dist. All ignition and fuel components (carb, fuel pump, distributor, alternator, starter) must be marine rated for safety. This is no joke, fuel and sparks in the bilge of an inboard can blow you into the next world. Do not cheap out on anything ignition, electrical or fuel system related on any inboard, no matter how cheap the boat was to buy. Also since we are talking safety make sure your bilge blower works and you use it properly and ALWAYS have the backfire flame arrestor in place when you start the engine.

What is the ESA module? I was thinking of switching in a Pertronics I'm place of the points. I don't see any module around the harness. This is an 89, has lot limited wiring for the engine to run.

 

[Lou C]

The ESA module will be located on the lower port side, under and behind the exhaust hose on that side but you can see it. It is a 3"x3" solid state module mounted to a bracket that is supposed to lower your idle rpm from about 600 down to about 450 when you shift from in-gear to neutral. By lowering the idle speed, it allows the clutch dog to release whatever gear you're in (FWD or REV) so the outdrive can go into neutral. The original ESA your boat came with will only work with a points distributor. If you put in an electronic distributor (marine rated, like the Delco EST) without changing the ESA module, you will have a lot of trouble shifting to neutral and the boat will be dangerous to operate because you won't be able to get it in neutral when you need to. So you have to factor that in too. CDI Electronics does sell the ESA modules that will work with electronic. I thought of doing this but just kept the points and replace them every few years.

Back to the fuel pump. Do you know that a marine pump is supposed to be wired through the oil pressure switch, so that if the engine stalls, it does not keep pumping gas into the carb? If not you need to find out how to do this for safety. I'd rather see you just replace the simple and very reliable (my engine is still on the OE pump!) mechanical pump that has worked great on carb'd Chevy small blocks since, oh well 1955 or so...

 

[Svshaw82]

The ESA module will be located on the lower port side, under and behind the exhaust hose on that side but you can see it. It is a 3"x3" solid state module mounted to a bracket that is supposed to lower your idle rpm from about 600 down to about 450 when you shift from in-gear to neutral. By lowering the idle speed, it allows the clutch dog to release whatever gear you're in (FWD or REV) so the outdrive can go into neutral. The original ESA your boat came with will only work with a points distributor. If you put in an electronic distributor (marine rated, like the Delco EST) without changing the ESA module, you will have a lot of trouble shifting to neutral and the boat will be dangerous to operate because you won't be able to get it in neutral when you need to. So you have to factor that in too. CDI Electronics does sell the ESA modules that will work with electronic. I thought of doing this but just kept the points and replace them every few years.

Back to the fuel pump. Do you know that a marine pump is supposed to be wired through the oil pressure switch, so that if the engine stalls, it does not keep pumping gas into the carb? If not you need to find out how to do this for safety. I'd rather see you just replace the simple and very reliable (my engine is still on the OE pump!) mechanical pump that has worked great on carb'd Chevy small blocks since, oh well 1955 or so...

How would I be able to prime the carb then if it won't engage without oil pressure? Electric seems to be alot less expensive then a mechanical too. Was planning to wire it off the ignition circuit so it only runs when the key is on.

 

[Bondo]

Ayuh,.... Electric fuel pumps should be powered from 2 directions,.....

Primary connection is through an oil pressure switch, from the ignition circuit,....
2ndary connection is a jumper from the outer tiny terminal on the starter's solenoid, to power it while the starter is engaged,...

It can NOT be powered directly from the key switch,...
It needs a safety cut-off that kills it if the motor ain't Runnin',....

 

[Lou C]

I picked up a spare mechanical pump for my engine for about 100 or so, also keep in mind the OE style pump will match up to your fittings, etc. No flex line is allowed on an inboard engine unless its the special braided marine line.

 

[Lou C]

How would I be able to prime the carb then if it won't engage without oil pressure? Electric seems to be alot less expensive then a mechanical too. Was planning to wire it off the ignition circuit so it only runs when the key is on.

Well if you notice when you crank your engine (look at your OP gauge) it will build pressure just by cranking the engine. The majority of the Vortec engines do not have a provision for a mechanical pump so they are all set up the way Bondo described

Doing your way, what happens if the engine stalls? With the pump getting power from the ignition on terminal on the ignition switch, it will continue to run even if the engine is not, which can create a fire hazard.