4.3L Distributor Should this model have Thunderbolt and ignition module?

[Leedanger]

1990 MCM 4.3L Serial #0C874052

Was this motor ever run with a points distributor? The one I have has a points distributor in it but when I look here http://www.mercruiserparts.com/Show_Pictures3.asp?dnbr=17468&ivar=images/COMMON/39265.png&inbr=951&bnbr=80&bdesc=DISTRIBUTOR+AND+IGNITION+COMPONENTS it shows a thunderbolt ignition. If it was never intended this motor be ran using points, will I continuously have issues with this engine?

 

[Don S]

Re: 4.3L Distributor Should this model have Thunderbolt and ignition module?

That rotor is used on both the Thunderbolt IV and V distributors. Same with the cap.

 

[Leedanger]

Re: 4.3L Distributor Should this model have Thunderbolt and ignition module?

I apologize Don I didn't form my question well at all. I should have simply asked if that motor will have issues if a Thunderbolt distributor is not being used as this one is not or will a points distributor suffice?

 

[Don S]

Re: 4.3L Distributor Should this model have Thunderbolt and ignition module?

Not sure what you're getting at, but rather the engine has issues, depends on the points distributor you put in it, and what the advance characteristics are of the points distributor.
Seems like a huge step backwards for that engine.

 

[achris]

Re: 4.3L Distributor Should this model have Thunderbolt and ignition module?

Hi Lee,

Just done some checking up, and the 262 (4.3L) engine only used breaker-less dissys, either TB IV or V. If you have a points distributor, then it might be from the earlier 229 (3.8L) V6, or an automotive unit. If it's from a 229, then it is for an uneven firing crank (the 262 has an even crank). Have a CLOSE look at the points cam lobes, if they alternate between a sharp peak and a slightly rounded peak, you have an old 229 dissy....

Chris........

 

[Leedanger]

Re: 4.3L Distributor Should this model have Thunderbolt and ignition module?

1990 MCM 4.3L Serial #0C874052

Was this motor ever run with a points distributor? The one I have has a points distributor in it but when I look here http://www.mercruiserparts.com/Show_Pictures3.asp?dnbr=17468&ivar=images/COMMON/39265.png&inbr=951&bnbr=80&bdesc=DISTRIBUTOR+AND+IGNITION+COMPONENTS it shows a thunderbolt ignition. If it was never intended this motor be ran using points, will I continuously have issues with this engine?

I edited my initial post to the quoted one above, hopefully that's helps it to be legible...sorry. Regardless I think I understand now but please correct me if I'm mistaken. This motor is setup to implement the thunderbolt system, if I continue to run the motor with the currently installed points system it's a coin toss as to how the motor will perform. Sound about right?

 

[81 Checkmate]

Re: 4.3L Distributor Should this model have Thunderbolt and ignition module?

Take a pic of your system, cap on, cap off and so on. I think this would help the experts. Could be that someone has changed out motor and kept the same set up on that package.

 

[Leedanger]

Re: 4.3L Distributor Should this model have Thunderbolt and ignition module?

Hi Lee,

Just done some checking up, and the 262 (4.3L) engine only use breaker-less points, either TB IV or V. If you have a points distributor, then it might be from the earlier 229 (3.8L) V6, or an automotive unit. If it's from a 229, then it is for an uneven firing crank (the 262 has an even crank). Have a CLOSE look at the points cam lobes, if they alternate between a sharp peak and a slightly rounded peak, you have an old 229 dissy....

Chris........

Hey Chris...

Just to be sure I'm not making things even more confusing I'll just post some pics like I should have from the start.

View attachment 131188View attachment 131189View attachment 131190

Thanks for your time gentlemen I appreciate it.

 

[achris]

Re: 4.3L Distributor Should this model have Thunderbolt and ignition module?

That looks very much like the 229 dissy.... So the answer to your original question about how well it will run in a 4.3... It will have 3 cylinders firing late (12 degrees late)... So you'll be seriously down on power, and the manifold vacuum will be jumping all over the place... In short, Not good...

 

[Leedanger]

Re: 4.3L Distributor Should this model have Thunderbolt and ignition module?

It is the MCM 4.3L 262 CID V6 so apparently as suspected by everyone this is the wrong distributor. Obviously to put the correct one on is the correct action, but I am curious the effects if any to keep this one in will have. Is it just as Don stated and simply a huge step backwards or could it also have extreme long/short term damaging effects?

 

[Leedanger]

Re: 4.3L Distributor Should this model have Thunderbolt and ignition module?

That looks very much like the 229 dissy.... So the answer to your original question about how well it will run in a 4.3... It will have 3 cylinders firing late (12 degrees late)... So you'll be seriously down on power, and the manifold vacuum will be jumping all over the place... In short, Not good...

Thanks Chris....

 

[achris]

Re: 4.3L Distributor Should this model have Thunderbolt and ignition module?

It is the MCM 4.3L 262 CID V6 so apparently as suspected by everyone this is the wrong distributor. Obviously to put the correct one on is the correct action, but I am curious the effects if any to keep this one in will have. Is it just as Don stated and simply a huge step backwards or could it also have extreme long/short term damaging effects?

Ok.. First up, you'll be using considerably more fuel than you should. You'll be loading up cylinders 1, 3, 5 more than the others, so they'll get hotter. The exhaust will be hotter as the energy released by the later firings will end up inn the exhaust system rather than as energy to turn the crank. Uneven cylinder pressures and temperatures will certainly not help the engine either.

Chris........

 

[Don S]

Re: 4.3L Distributor Should this model have Thunderbolt and ignition module?

I would say you need to get the right distributor for it. Earlier you said it was wired for the Thunderbolt, is the module and wiring still on the engine?

 

[Pete104]

Re: 4.3L Distributor Should this model have Thunderbolt and ignition module?

It's possible that the serial # you posted was for the original engine.
May have been replaced for whatever reason. Blown, froze or whatever.
I assume that number came off of the flame arrestor cover. Look down by the starter, riveted to the block is a 1" by 1.5" silver tag. It also has the serial # on it, they should match.
Merc was done with the 262cid around 88-89.

 

[Don S]

Re: 4.3L Distributor Should this model have Thunderbolt and ignition module?

It's possible that the serial # you posted was for the original engine.
May have been replaced for whatever reason. Blown, froze or whatever.
I assume that number came off of the flame arrestor cover. Look down by the starter, riveted to the block is a 1" by 1.5" silver tag. It also has the serial # on it, they should match.
Merc was done with the 262cid around 88-89.

The 229 cu in V6 was only used in 83 and 84. The 262 (aka 4.3L) came into existence with MC in 85 and is still in use today.
His SN is for a 4.3L 262 cu in V6 and used a Thunderbolt IV ignition system.

 

[Leedanger]

Re: 4.3L Distributor Should this model have Thunderbolt and ignition module?

I would say you need to get the right distributor for it. Earlier you said it was wired for the Thunderbolt, is the module and wiring still on the engine?

No....but I did notice the white w/grn wire which I was under the impression was for the ignition module, but I was shooting from the hip and going by memory. I've already ordered the correct part. Just to clarify incase anyone else is using this as a reference the serial I initially posted is the correct one. The boats a 1990 so really all the numbers ad up id you ask me, but maybe I'm just being argumentative now. Thanks again for everyones help

 

[Leedanger]

Re: 4.3L Distributor Should this model have Thunderbolt and ignition module?

I would say you need to get the right distributor for it. Earlier you said it was wired for the Thunderbolt, is the module and wiring still on the engine?

No....but I did notice the white w/grn wire which I was under the impression was for the ignition module, but I was shooting from the hip and going by memory. I've already ordered the correct part. Just to clarify incase anyone else is using this as a reference the serial I initially posted is the correct one. The boats a 1990 so really all the numbers ad up id you ask me, but maybe I'm just being argumentative now. Thanks again for everyones help

 

[Don S]

Re: 4.3L Distributor Should this model have Thunderbolt and ignition module?

The white/green wire also went to the shift interrupt switch. Here is the wiring diagram for that engine.


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