1989 Mercruiser 4.3

[Fiveo Invader]

I have a question regarding the 4.3 I/O Mercruiser. I am new to the site. After reading many of the threads, it seems that you guys know a thing or two. I purchased the boat yesterday and I cant get it to start. It wants to to start but its just turns over almost like theres no spark or the timing is way off.

Is this motor the same as a car motor? Can the timing retard that bad that it wont allow it to start? Any help would be awesome. Thanks alot.

 

[tommays]

Re: 1989 Mercruiser 4.3

How are you trying to start it

It is more like and old car

You need to use the Netural button and pump the throttle at least two full strokes to pump in some fuel and allow the choke to close

Then you need to play around a bit with the throttel position (about 1/3 )and then see what happens BE CAREFULL you loooking to warmup the motor at about 1500 RPM so the 1/3 position will take some learning to find the best spot

 

[Fiveo Invader]

Re: 1989 Mercruiser 4.3

Thank you sir the boat was winterized in November of 07. I have built motors before, GM small blocks, but wasnt sure about the boat. Does what I described sound like fuel or timing? the owner I purchased it from said it had a small knock or tap(explained as a valve tap on an old car) would that have any assistance in keeping it from starting? Also if I test it for compression like a car its the same for this?

I apologize for all the questions. I wanted a boat for years and finally got one. I dont need to tell the wife that its junk and I need another one.

Great forum by the way........

 

[PINESOL]

Re: 1989 Mercruiser 4.3

first things first .. do the compression test .pull all plugs , ground coil wire and open carb throttle plates turn the engine over 3 compression strokes per cylinder and report the readings back here ..
dons will be bye here soon to give you the proper link for doing the compression test and what to look for .. hes the merc guru .
welcome to iboats. keep your fingers crossed for an arching plug wire or something .. reguarding the tapping sound ... also note how the plugs look when you pull them out ..

 

[Don S]

Re: 1989 Mercruiser 4.3

If it was winterized, it may just have an empty carb. Make sure you have the drive down and water hooked up. The in the throttle only position pump the throttle a few times while cranking. May take the fuel pump some time to get fuel to the carb.
Is the emergency kill switch lanyard in or the switch in the on position (if it's the toggle style)?

 

[buggiedad_67]

Re: 1989 Mercruiser 4.3

does this modle have points???? you may just have a brunt set, try fileing and regap

 

[Bondo]

Re: 1989 Mercruiser 4.3

Ayuh,...... Welcome Aboard Five-0,.....

Basically,... For diagnostic purposes,... Your 4.3l is about the Same as 1 in a truck,....

If you want to Click,.. Right Here,... You'll find the Factory Service Manual for your Motor,....
What Year is the motor,+ drive,... Then We can find you the link for the Outdrive's Manual....

Btw,..... Tell Us more about the motor,.... Is it Carbed,..?? 2bbl. or 4bbl..?? EFI,..??

I really Doubt that you're really got Problems,.... It probably just needs a nice Spring Wake-Up Call.....
You'll notice, at the Top of the I/O forum, there should be a thread titled "Springerizing your boat",.....
Much of what you should be doing to it are explained in that locked thread,....
Courtesy of our Great Friend Dons,....

Good Luck,.............

 

[whywhyzed]

Re: 1989 Mercruiser 4.3

[......

 

[Fiveo Invader]

Re: 1989 Mercruiser 4.3

WELL!!!!!! thanks alot everyone.

heres the skinny....

1989 4.3 V6 Alpha one

Carb motor, 2 barrel.

1989 Invader 196 Bowrider.

The carb was rebuilt 2 years ago and the whole package was winterized in November. I am going to check the thread about the spring time wake up.

I paid $1000 for the boat, load rite trailer, and motor with a cover and the brand new bimini canvas top all the seats and floor are perfect and its original. it was kept and run down on the ELK river, never in the salt

Tommorrow is the day the work starts so ill let you know.........thanks for the help so far.

 

[Fiveo Invader]

Re: 1989 Mercruiser 4.3

So i got it started with a can of staring fluid, a jump box and alot of throttle it runs great at high RPMs. At idle it stalls and anywhere between 500 and 1800 its real rough.

I did notice a small leak in the intake manifold gasket. the smoke was the same color comin out of the carb. Could this leak cause the same diginosed problems as a set of bad rings?

I got the gasket and sealer for $40 and will finish today. Before i rip it off and reinstall it should i do a compression test first just incase? Thanks again.

 

[180shabah]

Re: 1989 Mercruiser 4.3

Before i rip it off and reinstall it should i do a compression test first just incase?

YES. Before you go any farther you need to determine what is good and what is not. THEN, you can replace/repair the problems.

after the compression test is done(if it is good) you can move on. Do you have spark (is the base timing correct)? Use a timing light. Is the fuel good, or has it been sitting so long that it has "soured"?

Just because the carb was rebuilt two years ago, doesn't mean that it is good. You don't know what has happened since then, if it has been sitting, it could be gummed up again.

Get rid of the starting fluid before you destroy your engine.

 

[Bondo]

Re: 1989 Mercruiser 4.3

So i got it started with a can of staring fluid, a jump box and alot of throttle it runs great at high RPMs. At idle it stalls and anywhere between 500 and 1800 its real rough.

Ayuh,..... That alone tells Me the Carb needs Rebuilding again.....

 

[cbear34]

Re: 1989 Mercruiser 4.3

Sounds like the carb is dumping to much fuel in the engine. Now that you have run it check the oil and see if there is a gas smell. Might just need a carb rebuild and adjusting.

 

[Fiveo Invader]

Re: 1989 Mercruiser 4.3

Thanks for all the input guys. So here the deal, the compression is fine according to the shop manual for the motor. I replaced the intake manifold gasket and carb gasket. The gasket on the manifold was gone on the odd side allowing water into the oil and extreme amounts of blow by on the intake runners.

Cleaned it up and reinstalled. with out any tune on the carb or plugs or timing and it started right up with out any help from starting fluid. A fresh battery and it kicked over first try. It runs perfect (minus a tune up of course) my brother and I are goin to get rid of the old gas thats in it since its about 2 years old.

The carb seems good but Im sure it wont kill me to clean it well.

Its coming along very well. I was very surprised to see such an easy fix. 3 or 4 oil changes and the motor shold be good. I want to get all the water out of the oil. I could see on the manifold where the water had blown by and into the oil down in the gulley by the cam.

Once again, thanks for the help and the info.

 

[Bondo]

Re: 1989 Mercruiser 4.3

Its coming along very well. I was very surprised to see such an easy fix. 3 or 4 oil changes and the motor shold be good.

Ayuh,...... That's Great that you've got a handle on it now,.......

Once you get the bulk of the Water out of it,.. Say by the 1st, or Maybe 2nd Oil Change,.......
Just run it for awhile, At Temps,+ the waterwill just Go Away by itself as Steam......
No sense in wasting Too much oil.......

 

[Fiveo Invader]

Re: 1989 Mercruiser 4.3

Oh ok I was under the impression that I needed to do numerous oil changes. What if I use used oil. I have some oil with like 1500 miles on it from my truck. Im going to waste what ever oil I put in there why not this stuff. Or should I just go with brand new and take the hit on the $$$. I want to do it right but am on a tighter budget than most I suppose. Thanks.

 

[JustJason]

Re: 1989 Mercruiser 4.3

double check your timing before you touch the carb.

 

[Fiveo Invader]

Re: 1989 Mercruiser 4.3

Yes I agree with the timing. The plugs are OK but the number 3 plug was fouled real bad, thats where the blow by was. I dont know enuff about carbs so if I adjust the timing and new plugs I dont have to do serious amounts of carb tuning? I have always worked on EFI motors and those are easy with a laptop and new chip.

As for the timing the distributor went in to the exact same spot that i marked it on the rotor and cap and manifold. I should only have to adjust a bit to smooth it out?

Thanks again.

 

[Gary H NC]

Re: 1989 Mercruiser 4.3

Before adjusting anything i would be sure it had fresh gas in it and the fuel filter or filters changed.Does it have the water seperator filter?

 

[Bondo]

Re: 1989 Mercruiser 4.3

Im going to waste what ever oil I put in there why not this stuff.

Ayuh,...... Sure,.... Why Not,.... I would....