Converting from motorola box to simple coil ignition system

[seattle scott]

Re: Converting from motorola box to simple coil ignition system

Thanks Frank.

 

[Nordin]

Re: Converting from motorola box to simple coil ignition system

After cleaning the screw check for cracks or insulation where the screew passes through distributorcasting/plastic isolation. The screw can ground out by touching the casting.

 

[seattle scott]

Re: Converting from motorola box to simple coil ignition system

I cleaned the terminal screw and the set nuts. I removed the nylon insulator sleeve and all looked good. Still no resolution. I will replace the points to rule that out.

 

[seattle scott]

Re: Converting from motorola box to simple coil ignition system

It was the points. Put in a new one and have spark to all plugs!!!!!!!!. Think I will hook up the fuel and see what happens. Thanks Nordin and Frank.

 

[Nordin]

Re: Converting from motorola box to simple coil ignition system

Seattle scott . You are welcome. I am at this forum trying to help other Chrysler/Force OB owners with their engines with my experience, and maybe learning some new things about these engines from others experience.

 

[seattle scott]

Re: Converting from motorola box to simple coil ignition system

Nordin, some more good new. The thing fired right up. I didntt have to fiddle with the timing. Didn't have to replace the fuel pump diaphragm, the carbs weren't all clogged up. Engine even idles fine. This was a non-runner that was on a boat we wanted. We left the 85 in the driveway and put our Chrysler 135 on the boat this summer. So we have a spare motor now. Compression is even 150 in all cylinders. I am happy. I think I will replace the impeller though. Spits out at the telltale, but not very much water flow - running in a tub.

 

[Nordin]

Re: Converting from motorola box to simple coil ignition system

Before using the 85Hp, adjust the carbs right. Do not set the air/fuel screws less the 1 turn out from lightly seated. Clean them (carbs) and put an inline filter between the pump and the carbs.
Proper adjusting save you from melting the pistons. The idling will be more rough with the screws 1 or more turn out, but much better then melting the pistons.

 

[seattle scott]

Re: Converting from motorola box to simple coil ignition system

Just a note of thanks. Had the boat out - lots of power. Ran about 10 gals gas through it and the charging volts don't change, not seeing anything above 12.4 -12.6, at WOT . I have the instructions for testing the AC volts from the stator and the DC volts from the rectifier, so I will get to that this weekend.

 

[pnwboat]

Re: Converting from motorola box to simple coil ignition system

The charging issue is easier than what you've went through earlier. Good job!

 

[seattle scott]

Re: Converting from motorola box to simple coil ignition system

It was the rectifier. Stole the one off the 135 and now I get about 14 volts dc coming off the rectifier at fast idle on the 85 hp.

After the first day of use, the plugs were wet fouled and the engine smoked a lot. I turned in the slow speed jets to about 3/4 turn out from seated. Next time out, engine would cut out after about 8 seconds at WOT, but would start up fine and run fine to about 1/2 throttle. When I pulled the plugs, they were absolutely "new in the box" clean. So I am running too lean. Reset the slow speed jets running in a tank, backed them out until the idle got rough and now have them at about 1 1/4 turns out from seated.

Would the having the jets set too lean, cause the engine to cut out/die going to WOT? I know too lean can wreak the engine.

 

[pnwboat]

Re: Converting from motorola box to simple coil ignition system

Yes if the mixture is set too lean, it may affect the WOT performance. A bad fuel pump diaphragm can cause the same symptom. Wet plugs and smoke are pretty much normal.

Too lean a mixture can cause damage to the pistons, however, if the motor ran OK afterwards, you probably didn't do any damage. You can kind of verify with a compression test and visual inspection of the piston crown through the spark plug hole.

 

[MickLovin]

Re: Converting from motorola box to simple coil ignition system

Seattle you need to do this the proper way and stop guessing, check the sticky for syncing your carbs. get those carbs right and you will have less problems and cause less problems, you have gone a 1/2 turn out from your original setting. My suggestion would have been to have it in a big tub, put it into forward around 750rpm and adjust your carbs 1/8 turn while waiting 10 seconds each turn. How did you come with a 3/4 turn out first? The manual states 1 turn from lightly seated then adjust from there. Read the sticky, Frank covers it well.
Then have a water test and try hole shotting it.

 

[seattle scott]

Re: Converting from motorola box to simple coil ignition system

Ok will start over and do the slow speed jets correctly per Frank's instructions. Had the boat out yesterday with the screws just set at 1 and 1/2 turns out ( just to get to the fishing spots) and same thing happened. Did a hole shot and just as engine gets to max rpms, without any bogging or stalls, engine dies out and is saved by going to idle and then throttling up to about 1/3 throttle and runs fine. A slow throttle increase leads to die out. Squeezing the fuel line bulb has no positive affect.

Thinking fuel issue though I checked the pump diaphragm and it looked good. There was some debris ( looked like red paint flakes from a metal gas can - from previous owner) caught in the pump screen , but I am not hopeful that is the cause.

 

[Nordin]

Re: Converting from motorola box to simple coil ignition system

Seattle, check the float level in the carbs. If to low it will caught out at higher RPM (starving).
While you check the floats clean the carbs too. Maybe you have dirt in the high speed system (jets and nozzles).

Does it cut out immediately or starve out?
If it cuts out it sounds like a timing issue. Then check the wires runing under the flywheel to the terminalblock and stator from bad isolation. It can rubb to ground while the timing advances when you increase the throttle.

 

[seattle scott]

Re: Converting from motorola box to simple coil ignition system

Thanks Nordin. It bogs out, takes 4-5 seconds to die. I took your previous advice and removed and cleaned the carbs. I just reset the slow speed jets and timing. Smooth idle and goes into gear with a very small "clunk". I then swapped out the fuel pump without any improvement. Then I added some better hose clamps to the fuel line from pump to carb ( replaced the squeeze type wire clips). Now I get about 60 - 70% RPMs ( though no tach) with no problem, though the motor does drop off and pick up a little every minute of so. the only thing I haven't done to confirm fuel starved is to spay gas in the carb mouths when it bogs out. but I am thinking it has to be something restricting the fuel before the carbs , since there is no missing or sputter when it bogs out. If there was something blocking in a carb, I would expect one cylinder to start missing ( one carb for each cylinder) not all 3 dying off at once. When I squeeze the fuel bulb I can see fuel filling the clear plastic fuel filter before the pump, bulb gets firm but no affect on the motor bogging out.

I am going to check the carb butterflies again to see if set up right and all open fully.

 

[bashr52]

Re: Converting from motorola box to simple coil ignition system

Glad to hear you have it up and running! I removed the motorola system off my 85 horse as well, except I replaced it with the old CDI box off my drag car. That is one good thing about these engines, since they are still points equipped, there are a ton of aftermarket options that will work if the factory system quits. You could even run an aftermarket tach off the points, if oyu could find one that would work with the pulses on a 3 cylinder, or just set it for a 6 cylinder and know you would to adjust the reading accordingly.