Mercruiser 165 I6 Pertronix 91163A hard start.

[Bergy]

So I replaced my points system with a Pertronix Ignitor 2 system. The engine runs great once it is running. My issue is that it seems harder to start than it was in the past. Before it was replaced, pumped the throttle twice and hit the key and it started immediately. After install of ignitor 2 I seem to have to crank a little to get it to start. Timing is set at 6 degrees before TDC and carb is set correctly. I think a read somewhere that ignition timing needs to be set at 4 degrees before TDC after Ignitor 2 is installed, but I can't find where I read it. Any help would be great.

 

[alldodge]

Timing doesn't changed based on which distributer is used. It should be timed at 8 BTDC
http://boatinfo.no/lib/mercruiser/manuals/mercruiser3.html#/34

 

[thumpar]

Did you run a full 12v to the pertronix? The pertronix doesn't change what timing you should be set at.

 

[Bergy]

Yes, full 12 volts. Wired to the the 12v side of the resistor. My Mercruiser book says 6 BTDC. Now I am really confused.

 

[alldodge]

My bad, these old eyes and to quick a look, you are correct it is 6 BTDC and not 8

 

[Bergy]

AllDodge, any ideas as to why it seems to start harder? I am lost and can't seem to be able to figure it out.

 

[airshot]

Any chance it is just a coincidence that it started having problems with the ignition change? In other words perhaps it is time for a tune or a carb rebuild? I might also suggest looking at the coil, when I changed mine over, a stock coil created starting issues but when I switched to a flame thrower coil, starting became much easier.

 

[Bergy]

I just did a tune up. I will look into a Flame Thrower coil.

 

[alldodge]

AllDodge, any ideas as to why it seems to start harder? I am lost and can't seem to be able to figure it out.

As airshot mentioned, it might just be by chance. Others have had trouble with the Petronix system, they work great or they have trouble. Sure this statement goes with most things, but with all the issues that keep showing up here, I'm just not impressed. Prefer the DTS

So far as the coil, any regular non-external resistor coil should work just fine

 

[biggjimm]

As airshot mentioned, it might just be by chance. Others have had trouble with the Petronix system, they work great or they have trouble. Sure this statement goes with most things, but with all the issues that keep showing up here, I'm just not impressed. Prefer the DTS

So far as the coil, any regular non-external resistor coil should work just fine

Alldodge, you say any "non-external resistor" coil should work fine but he said he wired the coil to the 12v side of his resistor. Unless he changed coils & didn't mention it, he is running an external resistor coil. Could that be his trouble?

 

[alldodge]

Alldodge, you say any "non-external resistor" coil should work fine but he said he wired the coil to the 12v side of his resistor. Unless he changed coils & didn't mention it, he is running an external resistor coil. Could that be his trouble?

Well..... ya know I saw that and blew past it. Yes if the resistor is still in line this will cause start and even some run issues

 

[Bergy]

Alldodge, you say any "non-external resistor" coil should work fine but he said he wired the coil to the 12v side of his resistor. Unless he changed coils & didn't mention it, he is running an external resistor coil. Could that be his trouble?

The coil is not wired to the 12 volt side of the resistor, just the Pertronix Ignitor 2. The coil is still wired the way it is supposed to be, through the ballast resistors. I say resistors, because there are 2 resistors. I think that since the boat is a 1968, it used 2 resistors rather than one resistor and a resistor wire as in later models.

 

[stonyloam]

Yeah, the Ignitor II is designed to work best with the Flamethrower II coil (0.6 Ohm). The Ignitor II has a variable dwell to allow optimal performance at all RPM ranges and it MAY be that it is not a good match for your stock coil. IMHO the Flamethrower II is a worthwhile investment. Here: http://www.pertronix.com/catalogs/pd...2015_coils.pdf I have the 45111 epoxy, but oil should work just as well. No ballast resistor required.

 

[thumpar]

When I put the Ignitor II on my old boat I did the Flamethrower II at the same time. It started easier and I gained a tad of WOT RPM.