Distributor not advancing

[cj7ole]

1989 Malibu skier w/ 350 mercruiser comp ski, standard points ignition, 4 bbl carb, 680 hours. I lost 800 rpm late last year, was hitting 4400, now I only get 3600. Mechanic looked at it, tweaked my valve adjustment (overheated last year, did valve job and new felpro gaskets) and said it was only advancing 24 degrees, whereas it should be advancing about 36 degrees at 3500 rpm. I took it apart and lubed the weights, seemed ok, but I checked again today and it is still advancing only 24 degrees.

Question, do I need a whole new distributor, or can I just get the guts? And if I get a new distributor can I just get an automotive one at my local parts dealer or do I need to get the Mercruiser replacement at nearly 3 times the cost?

 

[Bondo]

Re: Distributor not advancing

I just get an automotive one at my local parts dealer

Nope,... You need a Marine rated igntion system....

89 shoulda been a T-Bolt IV, not points...

 

[cj7ole]

Re: Distributor not advancing

Well, maybe it's time to upgrade to an electronic distributor, any suggestions? 350 Chevy is about as standard as it gets.

 

[LAC_STS]

Re: Distributor not advancing

When I upgrade mine I'm gonna use a Delco EST. The pro marine by me wants almost $500 but I found them online for $310.

Comes with everything you need including plug wires.

 

[Bifflefan]

Re: Distributor not advancing

You can buy a recurve kit and install it your self,

But don't.

Unless you have a good knowledge of a dist. and what and how they do what they do, you will mess it up.
You need a dist machine to get the curve dialed in to where it should be.
Just get a new good marine one and put it in.

 

[Don S]

Re: Distributor not advancing

Mechanic looked at it, tweaked my valve adjustment (overheated last year, did valve job and new felpro gaskets) and said it was only advancing 24 degrees, whereas it should be advancing about 36 degrees at 3500 rpm

Odd, the book calls for 18? to 21? degrees of advance for the MIE Ski engines.
Do you have the dwell on the points set properly and the intial timing set at 10? at idle rpm (700 rpm)?

You seem to be pinging on the ignition system as the problem, have you looked into a fuel delivery issue at all. Seems more likely to me.
Have you checked for air leaks in the fuel system up to the fuel pump or maybe a partially plugged pickup, antisiphon valve, or pickup tube in the tank.

Might try an outboard tank with new clean fuel and see if your rpms pick up.
Could also be carb problems as well.

 

[EddiePetty]

Re: Distributor not advancing

........ and said it was only advancing 24 degrees.......... whereas it should be advancing about 36 degrees at 3500 rpm.........

...if the distributor was ADVANCING 24 degrees, 'nuttin' wrong with that!!! Combined with your 8-10 degrees of initial timing you're right on the limit for your engine speed and regular fuel.

Agreeing with Don S., I think you're lookin' under the wrong bushel basket.

 

[cj7ole]

Re: Distributor not advancing

I am getting a total advance of 24 degrees, which is 16 degrees of advance due to the weights in the dizzy on top of the initial 8 degrees timing.

 

[a70eliminator]

Re: Distributor not advancing

The relutor arm the distributor shaft has a slot that limits total advance the spring and weights just manages the RPM range it takes to reach the limit. The reluctor arm usually has two different slots, one a little wider then other and the advance markings are usually stamped on it like 10L or 14L the arm can be flipped over to use either one, but it also means pulling the distributor because it put it 180 degrees out. Does the little rubber bumber go full range of the slot stop to stop? that's all the mechanical advance that dizzy will get.
I almost forget to mention from a previous thread where someone had pulled the threads out of the breaker plate and put a longer screw in there and it interfered with the advance mechanism, just though I should mention that.

 

[cj7ole]

Re: Distributor not advancing

When you say Delco EST are you saying that you have a computer to run it. Or do you mean Delco HEI. An EST will not operate properly without a computer

I know this is from a really old post (exactly 7 years to the day), but it ( "An EST will not operate properly without a computer.") contradicts what I see in other posts. I ordered the EST distributor from Marine Engine Depot for $301 delivered (really good price), but am afraid to prodeed with the install if this is correct. Plus I misplaced the instructions. I have a 1989 Malibu Skier with the 5.7 Mercruiser Skier engine with points and a carb, no computer. Am I good to use this as a replacement for the Prestolite in there now?

You may be right that I don't need a new distributor, but now that I have it, I might as well go with the upgrade. I did replace the fuel filter, no change. I ran across this chart indicating that 25 degrees of total advance is in the ballpark. I'm not going to use that mechanic again.

DELCO IGNITION TIMING CHART

ENGINE INITIAL TIMING TOTAL TIMING
CID @ 500 RPM @ 4000 RPM

181 0o 24o
250 10o 32o
262 2o 24o
305 8o 26o
350 8o 25o
454 12o 30o
552 12o 30o
Warning: These timing Numbers should be verified with your owners manual. These are not necessarily true for every engine setup, and variances can occur. Use these as a reference base only.

 

[Don S]

Re: Distributor not advancing

Start a new thread with what you want, not what someone posted in 2004. They were wrong.
But stop bringing up old threads that have nothing to do with the question you now have.
Buttanic has not visited the forum since Feb 09.