Merc 4.3 v6 distributor cap and cilinder connections

[wake800]

Hey guys, I got a used Regal 2005 boat with a MerCruiser Chevy Vortec 4.3 v6. Im checking my t's because it is only getting 3600rpms and max 33 mphs. With a three blade 19 pitch and 4 blade 17 pitch both around 14 inches. Im pretty sure i know it can get more so I've been checking things on the boat and the forum.

Two questions about the distributor cap:
One is if in the pictures i have attached does it look like it needs to be changed?

2nd - is it connected correctly, the motor turns fine and works but according to the timings and what cylinder should be connected to what point-needle on the dist cap they would ve incorrect. Im not sure if i should move the wire plugs to how they are supposed to be. The diagram below is how it is connected as of now and the bottom part is the front of the boat and the distributor cap is how it looks from above on the motor installed exactly.

Thanks for the help








1. I drew a diagram of how

 

[Scott Danforth]

Your sketch is wrong

Cylinder 1 is port forward

 

[wake800]

Your sketch is wrong

Cylinder 1 is port forward

Hey Scott could you elaborate? This sketch that I drew is how the motor/distributor/cables would look if you were looking towards the stern with the port side on your right side while looking back. From what I have seen from other images explaining the numbers --- is number 1 cylinder would be on the "lower right" of the image and 2 on the lower left.

 

[Scott Danforth]

Follow your sketch. You have tower 1 of the dizzy going to cyl 3

 

[Scott Danforth]

Why not just use the proper GM or Mercruiser diagram

 

[QBhoy]

Scott is spot on. And that picture of it, if it’s your actual unit, suggests it’s well used too. The main king lead central node is just not looking too good at all.
Is this your actual unit on your engine ? What 4.3 is it ? Is it a tks carb ?

 

[wake800]

Follow your sketch. You have tower 1 of the dizzy going to cyl 3

Thats what i was looking at, from what i can tell its all connected wrong. My question is if the boat turns over or turns on and works could this incorrect placement cause it to get lower rpms etc. The people i have asked tell me if it where not connected correctly the boat wouldnt even start or it would sound bad when cranking the motor.

Thanks in advanced.... Trying to learn i switched from two 2 stroke yamaha exciter

 

[wake800]

Scott is spot on. And that picture of it, if it’s your actual unit, suggests it’s well used too. The main king lead central node is just not looking too good at all.
Is this your actual unit on your engine ? What 4.3 is it ? Is it a tks carb ?

This is how its been used for the last couple of years by the previous owner with the set up on the diagram i drew. Im thinking thats affecting low rpm on WOT.

merc chevrolet vortec 4.3 v6 thunderbolt v ignition i think 2bbl carb

I have attached an image of how i think it is supposed to be connected, is this right? Also I have attached a pic of what my distributor cap looks like, i see it has two numbers is this if it turns left or right??

 

[QBhoy]

If it was wrong, it might run…but you’d know all about it if was in the wrong order. Be very obvious and eventually detrimental.
Follow the proper rotation firing order and defo replace that cap and rotor. It looks almost beyond use.

 

[QBhoy]

This is how its been used for the last couple of years by the previous owner with the set up on the diagram i drew. Im thinking thats affecting low rpm on WOT.

merc chevrolet vortec 4.3 v6 thunderbolt v ignition i think 2bbl carb

I have attached an image of how i think it is supposed to be connected, is this right? Also I have attached a pic of what my distributor cap looks like, i see it has two numbers is this if it turns left or right??

Ok. Quite plain to see what’s going on after you posted these pics.
So most normal LH rotation engines are 1-6-5-4-3-2 order.
Looks like your cap if it’s pictures as being the same as the one on the right showing that cap, is telling me that is a RH reverse rotation part. They are 1-2-3-4-5-6 I’m sure. Is it a LH conventional engine you have ?

 

[QBhoy]

Strange one I think though. If you had a RH cap on a LH engine it just wouldn’t work out well. Don’t think it would even start with the starter throwing it the opposite rotation. It would be running the wrong way if it did and not pumping oil and all sorts I’d think.
Perhaps you have a RH engine ? What’s the set up. Is it a single engine and driving a alpha ? Is it a right hand prop or left when in forward gear ? Is the engine original to the boat or is this one of two engines in a twin engine boat ?

 

[wake800]

Ok. Quite plain to see what’s going on after you posted these pics.
So most normal LH rotation engines are 1-6-5-4-3-2 order.
Looks like your cap if it’s pictures as being the same as the one on the right showing that cap, is telling me that is a RH reverse rotation part. They are 1-2-3-4-5-6 I’m sure. Is it a LH conventional engine you have ?

Yes it says on the filter its a LH rotational engine. So i wow id be using the clockwise numbers by the towers right?

 

[QBhoy]

Yes it says on the filter its a LH rotational engine. So i wow id be using the clockwise numbers by the towers right?

If it’s left hand…you’d be using a conventional set up and be 1-6-5-4-3-2 firing order and suited cap. If it was a RH cap..I don’t imagine it would run hardly at all.

 

[wake800]

Strange one I think though. If you had a RH cap on a LH engine it just wouldn’t work out well. Don’t think it would even start with the starter throwing it the opposite rotation. It would be running the wrong way if it did and not pumping oil and all sorts I’d think.
Perhaps you have a RH engine ? What’s the set up. Is it a single engine and driving a alpha ? Is it a right hand prop or left when in forward gear ? Is the engine original to the boat or is this one of two engines in a twin engine boat ?

Will change the distributor cap as per your observations. As for the engine its LH engine, with alpha one sterndrive, rh propeller, the engine is orginal. Single engine

 

[wake800]

I double checked the connections from the towers to the spark plug and thats how it connected. My diagram even has the 1 like if you where looking at the motor with port side on your right side (you looking back at the stern) , the motor doesn't sound bad at all but it does have low rpms

 

[QBhoy]

I double checked the connections from the towers to the spark plug and thats how it connected. My diagram even has the 1 like if you where looking at the motor with port side on your right side (you looking back at the stern) , the motor doesn't sound bad at all but it does have low rpms

I’d say you likely would t have any rpms if it was trying to run backwards. So many things would be wrong if it was. If you have the LH dizzy, your low rpms would almost certainly be unrelated to this topic. I’d suspect you’d be looking elsewhere for your issue. Like fuel delivery and quality. Fuel filter, compression check and health of engine. Prop pitch etc etc etc. or just plain simple down to the poor condition of the diz cap you have.

 

[wake800]

I’d say you likely would t have any rpms if it was trying to run backwards. So many things would be wrong if it was. If you have the LH dizzy, your low rpms would almost certainly be unrelated to this topic. I’d suspect you’d be looking elsewhere for your issue. Like fuel delivery and quality. Fuel filter, compression check and health of engine. Prop pitch etc etc etc. or just plain simple down to the poor condition of the diz cap you have.

Thanks for the help, will change the dist cap, and will be doing maintenance on it this week, changing spark plugs, oil, impeller, filters. And compression. If not i will chime in to see what it could be.

Would you suggest following this diagram to where the wires should be connected? Or is there another diagram with a different way to connect it?

 

[Bt Doctur]

You can reverse 2 plug wires and it wont even get on plane, just follow the diagram in post 7

 

[wake800]

You can reverse 2 plug wires and it wont even get on plane, just follow the diagram in post 7

I really am dumbfounded and will be able to try it this thursday, but right know it is connected like this the first number being the tower # the second the cylinder number going clockwise or LH. As per post #1 diagram

1 to #3 cyl
6 to #2 cyl
5 to #1 cyl
4 to #6 cyl
3 to #5 cyl
2 to #4 cyl.

Like i said it cranks fine 33 mphs.... i cant seem to find the reason or why it would be connected like this.
I will be changing the coil cable as i think it is also open

 

[Scott Danforth]

Never assume the tower on the dizzy is in a specific location. The tower the rotor is pointing to when the motor is at TDC is number 1