Mercruiser 140 Points to Delco EST results in low RPM at WOT

[ahicks]

I haven't worked on a 140 for 45 years or so, so disregard if this no longer applies. Back then we had issues setting the dwell consistently on occasion, due to the fact the rotor shaft was riding in badly worn bushings, that required a new housing to repair. .030 slop in rotor shaft not too unusual, making setting points near impossible.

Here, clearly the point issue is no longer in play, so wondering if that rotor shaft running in a worn out bushing could still be an issue?

 

[j cat]

Here is the engine plate for reference

View attachment 358405


So suggestions so far is to set base timing mode then adjust to 8* btdc and try from there? Verify total timing at wot is near 34*?

the idle rpm is 650-700 set up the timing 6 deg BTDC...then see if the timing increases around 1200 rpm and the timing is around 8DEG BTDC..
the distributor works correctly ....
the dwell meter looks up idle rpm 30deg .. in that spec..
I bought my 1967 442 in july 1967.. I had to change those points every 12K miles ...I have my 1967 dwell meter LOL....470 mec engine ..
I lube the dist metal weights on my 442 .. clean it up .. the capacitor changes it .

 

[Lou C]

the idle rpm is 650-700 set up the timing 6 deg BTDC...then see if the timing increases around 1200 rpm and the timing is around 8DEG BTDC..
the distributor works correctly ....
the dwell meter looks up idle rpm 30deg .. in that spec..
I bought my 1967 442 in july 1967.. I had to change those points every 12K miles ...I have my 1967 dwell meter LOL....470 mec engine ..
I lube the dist metal weights on my 442 .. clean it up .. the capacitor changes it .

Do you have the Delco window distributor where you can change the dwell by using an allen key when the engine is running? I had one on my '72 Chevrolet, and the flex allen tool to adjust it. You couldn't have that on a marine engine (has to be sealed due to sparking) but on a car engine, that sure makes setting them EASY!

 

[j cat]

Do you have the Delco window distributor where you can change the dwell by using an allen key when the engine is running? I had one on my '72 Chevrolet, and the flex allen tool to adjust it. You couldn't have that on a marine engine (has to be sealed due to sparking) but on a car engine, that sure makes setting them EASY!

yes the 442 has the metal door and adjust the points. ...
the merc 470 engine the distributor is not a door ... and prior it was a lot of time to adjust the 470 points.....
25 yrs later on my 470 I setup the pertronix 1146A electronic ignitor ..
I start up the engine in the spring and I use a timing gun and the timing is 8DEG BTDC the RPM is 650 RPM ..I take the cap off and the cap looks like new.........now the PTS 25yrs later the carbon is in the cap... !!!! dirty..
my 1996 IMPALA has a distributor .. 350CU LT1 ... the cap has a vac line to the cap... then the air filter intake line goes to the cap .. 2 hose lines ..
the carbon is very small amount ..
boat engines have PTS in the cap .. then the carbon creates arcing and breaking down the cap insulation ... then the engine back fires ...

 

[me78569]

weather decided to roll in and it is snowing again so I wont be able to get this tested in the water for a few weeks, but once it warms up a bit I will verify with the muffs base timing at 6* and what it does at 1200 rpm and then 2200 rpm with the timing light.

 

[Lou C]

yes the 442 has the metal door and adjust the points. ...
the merc 470 engine the distributor is not a door ... and prior it was a lot of time to adjust the 470 points.....
25 yrs later on my 470 I setup the pertronix 1146A electronic ignitor ..
I start up the engine in the spring and I use a timing gun and the timing is 8DEG BTDC the RPM is 650 RPM ..I take the cap off and the cap looks like new.........now the PTS 25yrs later the carbon is in the cap... !!!! dirty..
my 1996 IMPALA has a distributor .. 350CU LT1 ... the cap has a vac line to the cap... then the air filter intake line goes to the cap .. 2 hose lines ..
the carbon is very small amount ..
boat engines have PTS in the cap .. then the carbon creates arcing and breaking down the cap insulation ... then the engine back fires ...

Just curious, how do you like the Petronix? I have heard mixed things.

 

[Scott Danforth]

yes the 442 has the metal door and adjust the points. ...
the merc 470 engine the distributor is not a door ... and prior it was a lot of time to adjust the 470 points.....
25 yrs later on my 470 I setup the pertronix 1146A electronic ignitor ..
I start up the engine in the spring and I use a timing gun and the timing is 8DEG BTDC the RPM is 650 RPM ..I take the cap off and the cap looks like new.........now the PTS 25yrs later the carbon is in the cap... !!!! dirty..
my 1996 IMPALA has a distributor .. 350CU LT1 ... the cap has a vac line to the cap... then the air filter intake line goes to the cap .. 2 hose lines ..
the carbon is very small amount ..
boat engines have PTS in the cap .. then the carbon creates arcing and breaking down the cap insulation ... then the engine back fires ...

no need to have the engine running to read a dwell meter, you can read it while cranking the engine.

no door is because the door is not J1971 comliant.

 

[Lou C]

That's how I do mine, just hook up the remote starter and crank it with the cap off and coil high tension lead grounded. Saves time!
Yep there's no way that the sliding door would pass the spec for ignition protection, true marine distributors have a gasket under the cap and a vent with a metal screen in them, to keep an explosive mixture from igniting outside the distributor.
BUT, if you had a Delco window distributor in the days before electronic ignition, you were the envy of your friends with Fords and Mopars. They were especially handy on V8s in Chevrolets, Pontiacs & Oldsmobiles due to the distributor being at the back of the engine. Laying on top of the motor to do points was not our favorite task back then. Small block Mopars also had the distributor in the rear, also a pain with points. Ford V8s had em all in front.

 

[me78569]

question about setting base timing. when I have the initial timing connector connected the the Delco and 12+V supplied I set my base timing. I set this at 6*, when I remove the Initial Timing Connection should timing stay at 6* or should it jump to something else?

I am not sure if I should be able to take my timing light and see 3 different readings for timing or just 2 different timing readings.

1. base timing with the Initial Timing Connector connected, I set this at 6*
2. idle rpm timing without the initial Timing connector connected, I read this at 6*
3. 2K+ rpm timing jump

I was able to get timing to run up to ~30* of timing at higher RPMS, total timing is a guess since the indicator marks stop at 12*, but using a ruler and marker I have guessed where 30* would be.

 

[alldodge]

have the initial timing connector connected the the Delco and 12+V supplied I set my base timing.

I just had a Homer Simpson DOH moment

With your original points dizzy, the shift interrupter is normally open (NO) and closes to apply a ground to the coil to make the engine Miss.

The new dizzy uses NO contact and supplies 12V to the dizzy to make it Miss

The new dizzy will need to have the I-switch wire going to ground ground side and move it to the purple wire for 12V

EDIT: changed the new dizzy comment

 

[alldodge]

I changed previous post

 

[me78569]

I just had a Homer Simpson DOH moment

With your original points dizzy, the shift interrupter is normally open (NO) and closes to apply a ground to the coil to make the engine Miss.

The new dizzy uses NO contact and supplies 12V to the dizzy to make it Miss

The new dizzy will need to have the I-switch wire going to ground ground side and move it to the purple wire for 12V

EDIT: changed the new dizzy comment

I will get out my multi meter and verify that the I-Switch is sending ground through when applied, then if that is the case I will make it so there is 12V flowing to the i-switch so when the i-switch is triggered the dizzy see's 12v

Is that the correct line of thought?

 

[alldodge]

I will get out my multi meter and verify that the I-Switch is sending ground through when applied, then if that is the case I will make it so there is 12V flowing to the i-switch so when the i-switch is triggered the dizzy see's 12v

Is that the correct line of thought?

Yes, here is the 3.0 with EST. Note the 12V

 

[me78569]

Thanks for the wiring diagram that helps a ton.

How does this change the lack of timing? Or does it?

 

[alldodge]

Depending on what was and was not connected when timing it may have no bearing. You mentioned connecting dizzy to 12V so that part is good. Jumping the 2 whites together

 

[me78569]

Well my boat was already wired NO 12v but not the the dizzy. White with green stripe goes into the i-switch as 12v then a black wire out to someplace, I am tracking that down.

 

[alldodge]

Your probably getting 12V from the Neg side of the coil with key ON.
The white/green connects to Gray or connects at the coil. Most likely there are 2 wires on the coil Neg side

This is how you should have been wired prior to EST

 

[me78569]

I've spent more time than I want to admit looking for that diagram. Thanks.

 

[alldodge]

Its in manual 10

 

[me78569]

sorry I don't know what Manual 10 is. I've looked through the stickies etc and most of the links are dead. Can you point in the right direction?