problem solving engine trouble

You may want to check your timing chain for wear. See other thread, just move crank with a wrench & see if dizzy moves immediately.

That's what an E spark for the screw down cap should look like.

If you want to get at the photo electric eye you have to pull the shutter/rotor assembly off, sometimes they can be stubborn

KenO

Lift Films wrote: Ok. I have a new coil ordered.    I'll get the rotor and cap cleaned up and double check the wiring once the coil comes in. Hopefully my problem is with the coil.    How do you know what coil will work with the e spark?    The coil currently on the boat is a C819 (autozone).

That Duralast c819 coil is 1.5 ohms according to auto zone.

You would wire your e spark per figure 5 of the instructions I attached at the bottom of page 2 of this thread. You would have a ballast resistor as part of this wiring.

The mallory 29219 coil gets wired with no ballast resistor.

The odd part is that it's also about the same resistance. It's 1.4 ohms.

So the 64,000 dollar question is why the Mallory coils that they specify in the instructions (the 29219 is one of them) don't need a ballast resistor.

I don't know the answer but that's the coil I've been using for quite a while with no issues. Must have to do with the coils internal construction.

The 29217 is wired per figure 7

Lift Films wrote: Thanks KENO.     Should the coil be the same as the one you mentioned earlier? UF-2?

The coil I've been using with an e spark is a Mallory 29219

mallory instructions

The linked instructions talk about coils and ballast resistors right at the beginning, the 29219 is one of the 3 listed for use without a ballast resistor.

I went that route and haven't had any problems

The instructions can be confusing, these particular ones are for an e spark in a Mallory distributor but the wiring is the same for all the e spark kits.

Thanks KENO.     Should the coil be the same as the one you mentioned earlier? UF-2?

KENO,

Just getting back on this.   I just double checked and my distributor has the electronic conversion.

It has the screw down cap with a Mallory 6100M Distributor Module.    What do you recommend doing on that?    

My 78 had a serial number in the back drivers side right below the rub rail and the year of build was in that number.

Lift Films wrote: I'm moving to ignition now.   My boat has standard ignition with points.   I'll start checking each of KENO's suggestions off the list.    thanks for the help.

If you want some part numbers, here goes. These are for the Prestolite clip down cap which is what came on the 76's. If you have the later screw down cap the cap and rotor are different

These are all Standard Motor Products but could be cross referenced to another brand

Points     AL-5677P

Condenser AL-118

Rotor      AL-153

Cap        AL-140 (cheap one) or AL-483 (expensive one, brass contacts instead of aluminum)

Coil          UF-2

Ballast resistor RU-4   (RU-23 or RU-37 will work too)

Or you can go to discount Inboard Marine's website and get a 1301 tuneup kit (cap, rotor, points and condenser) and 1243 ballast resistor and 1223 coil.

May or may not cure your problem, but you'll know your ignition system is right.

KenO

Listen to KENO. I'd continue to troubleshoot the ignition... Doesn't sound like carb. I've seen EI modules misbehave at specific rpm and act fine above/below.

Lift Films wrote: [QUOTE=KENO] Hi LiftFilm It is a prestolite sae-j1171 Once you get to 3500 rpm the problem goes away completely.     at 3000 rpm it is there but almost unnoticeable.   at 2500 it is the worst.    below 1800 it is non-existent.

The SAE j1171 just m eans it's a marine distributor. That was the SAE testing that qualified it as marine. But at least you know it's a marine Prestolite

If it's points and you haven't touched them in a while, I'd do points, rotor, cap and condenser and a coil while I was at it. Just a stock replacement type coil
Can't hurt that's for sure.

Electronic might have it's own set of problems that would be a little harder.

KenO.

Hi LiftFilms

Having read thru all of this thread and all of last year's, I don't see any mention of what kind of distributor you have.

Lots of talk about timing and advance mechanisms, nothing about points or electronic.

I've seen both do some strange things.that are hard to explain.

Will the boat run at say 3000 or 3500 rpm's for a minute or more with no issues?

If I put on a brand new carb and that didn't resolve my issues I'd be looking elsewhere and I can't count how many times over the years I've been sure something was a fuel issue only to figure out it was ignition instead

KenO

MrMcD wrote: I see you set the timing and I guess you did this at idle which is normal. Engine performance is very much controlled by the Mechanical advance in your distributor. It normally functions perfectly and is invisible. When they act up you need to verify what they are doing to fix them or verify it is working perfect and move on to other potential problems. The simple check would be to hook up the timing light to your number one spark plug. If you question what plug is number one, look down on the front of your engine above your fan belts. As you look down notice that one cylinder head is actually about 1 inch forward of the other cylinder head. The forward head and the front cylinder is where your number 1 plug will be located, Chevy, Ford Chrysler all the same., With the engine running and timing light working have a partner rev the engine up slowly from idle 650 RPM to 4,000 RPM watch the timing mark on your harmonic balancer move. It should move from the factory setting of 5 degrees or so at idle all the way up to 35 degrees by 3,000 RPM. If it is sticky, jumpy or does not move this is a major issue and needs fixed. Fix is simple, take the cap off the distributor remove the points and condenser and get down to your advance weights under the points. Make sure they are clean, no rust. The springs are still attached. Turn the shaft gently and watch the springs move and the weights swing. Make sure the weights are clean and smooth. If you take them out a quick smoothing with 600 grit sand paper will make them work well again. I always coat them with a very thin film of marine grease. I understand many say to keep them bone dry. I use the thin coating, just a film, to help avoid future rust. I know the coating can attract dirt and dust. Choose your poison, dirt or rust both can mess it up. Timing should advance as RPM goes up. If you are 5 at idle it might be 15 at 1,500 RPM and 20 at 2,000-2,500 and max at 35 + or - 1 at 3,000-3,500.   Keep checking all the way to 4,000 so you are positive where it stops advancing. As was mentioned many posts back on this thread timing could cause your issues if it is not advancing correctly as your RPM go up.

thanks.   I'll double check this today.    Pretty sure timing is advancing correctly though.   I'm not getting any pings or backfires.   Boat accelerates fine and runs great at high RPMs.    Also not sure why it would run fine for a minute before the stumbling starts if it was a timing issue.    It is literally like clock work.   It'll run perfect at 2500 RPM for 1 minute and then start stumbling every 3 seconds until you accelerate.   When you bring it back down to 2500 rpm it will take another minute to start stumbling.   

and maybe stumbling is the wrong word.    It sounds like a bog; as if it's getting too much fuel or starving for fuel.   

SNobsessed wrote: You could watch the secondaries' linkage when it is acting up. Maybe there is something wrong with the secondaries vacuum diaphram, like a pinhole.

Good idea. We thought the same thing and watched these good.    No sign of leakage from secondaries..

I see you set the timing and I guess you did this at idle which is normal.
Engine performance is very much controlled by the Mechanical advance in your distributor.
It normally functions perfectly and is invisible.
When they act up you need to verify what they are doing to fix them or verify it is working perfect and move on to other potential problems.
The simple check would be to hook up the timing light to your number one spark plug.
If you question what plug is number one, look down on the front of your engine above your fan belts. As you look down notice that one cylinder head is actually about 1 inch forward of the other cylinder head. The forward head and the front cylinder is where your number 1 plug will be located, Chevy, Ford Chrysler all the same., With the engine running and timing light working have a partner rev the engine up slowly from idle 650 RPM to 4,000 RPM watch the timing mark on your harmonic balancer move. It should move from the factory setting of 5 degrees or so at idle all the way up to 35 degrees by 3,000 RPM. If it is sticky, jumpy or does not move this is a major issue and needs fixed.
Fix is simple, take the cap off the distributor remove the points and condenser and get down to your advance weights under the points. Make sure they are clean, no rust. The springs are still attached. Turn the shaft gently and watch the springs move and the weights swing. Make sure the weights are clean and smooth. If you take them out a quick smoothing with 600 grit sand paper will make them work well again.
I always coat them with a very thin film of marine grease. I understand many say to keep them bone dry. I use the thin coating, just a film, to help avoid future rust. I know the coating can attract dirt and dust. Choose your poison, dirt or rust both can mess it up. Timing should advance as RPM goes up. If you are 5 at idle it might be 15 at 1,500 RPM and 20 at 2,000-2,500 and max at 35 + or - 1 at 3,000-3,500.   Keep checking all the way to 4,000 so you are positive where it stops advancing.
As was mentioned many posts back on this thread timing could cause your issues if it is not advancing correctly as your RPM go up.

What did your manual tell you to set timing to ?