engine just quits

[shiloh87]

Hello again, back with more 1984 470 issues.
My last inquiry was, having trouble locking down the distributor. Figured that out and fixed it, no issues with that until today.
Went out for a cruise today and after about 45min of cruise we stopped to have an little lunch break. After about an hour or so fired up the boat and headed home. Was running great again for about 5min then the engine shut down, no surge, sputter or back fire, just off like the key was turned off.
Upon trying to restart it would just kick over and die?? So now after 20 or so minutes I got it going rammed it into forward a cruised home at @3000rpm no problem, slowed down to idle while approaching the dock no issues.
Once home, I put the muffs on and fired it up to check the timing. It was still there but erratic, seemed to be idling fine then just cut out again like it did earlier on the homeward run. I checked the coil voltage with key on and got 2-2.5v, battery fully charged.
I did the Pertronics conversion last yr with the 3ohm flame thrower coil, replaced the resistor wire etc, I did notice the coil was pretty warm but not burny hot. This pig ran great all last season, but so far this yr, not so much .
Would erratic timing be caused by over heating coil or am I missing something?
I`ve been over every thing, fuel, charging, compression, fluid leaks, cooling and it all checks out, which seems to keep bringing me back to ignition. Are these Pertonics systems junk?
Rick

 

[achris]

Are these Pertonics systems junk?
Rick

I haven't any personal experience with the Pertronixs, but a few people here have had issues with them.

One suggestion I would make, and given your previous problem of the distributor moving this may have merit... I would run a dedicated ground wire to the distributor body (I'd even go so far as to bolt that wire to the breaker plate). As the points/Pertronix are inside the distributor, then it absolutely needs a good ground. If it looses ground, then it will be like the key was turned off.

Chris..........

 

[shiloh87]

Makes sense, I`ll give that a try.

 

[dubs283]

2-3 volts seems low for primary coil voltage. Key on engine off should see around 9-10 volts on the positive side. Negative side voltage may vary, like chris I have little experience with the upgrade kits and ime they either work or they dont

 

[shiloh87]

Ya, I thought it was low as well. Going to investigate that today.
I`ve installed a dedicated ground as Chris suggested, from the breaker plate to a block ground.
After I figure out the low voltage I`ll try to fire it up and see what I get.
Thanx so far gents, fingers crossed.

 

[shiloh87]

Turned on key, engine off, and checked coil voltage immediately, 1-2v, waited a bit while the coil energized then got a reading of 9v, so that`s good.

 

[shiloh87]

Yesterday I fired up the engine and reset the timing, with the dedicated distributor ground and it ran fine for the time I was working on it, around 15min.
On the #1 wire timing held fine at 4deg btdc and the advance was spot on. Moved to 180deg, #4 wire, timing was good but advance was erratic at best, jumping around.
Now as I asked before could this be a result of the electronics (pertronics 1149A) upgrade or is my distributor pooched(advance mechanism sticking). I pulled this delco distributor from a 470 same yr as mine that only had 136hrs on the clock, and it checked out before I installed it.
It would seem disappointing if the investment of the upgrade failed after 1 season, if so chock it up to more Chinese junk as I`m sure that`s where Pertronixs would be sourcing their components.
Any thoughts?

 

[shiloh87]

Hello and Merry Chritsmas from the great not so white north, no snow
Its been over a yr, most gremlins are sorted on this project, boats running great when running LOL
Getting 45mph wot with just me.
Back to the engine just quits, I`ve come to the conclusion that a short or other gremlin. exists in the main engine to dash harness.
On a calm flat water day, we can rip around for hour of fun with out issue. Go out on a choppy bumpy day and within minutes it`ll die after the first hard hitting wave jump.
Maybe this winter I`ll redo the harness of just sell her and build another kayak.
Cheers and safe holidays.

 

[ROY WILLIAMS]

MY BOAT MCM470 1978 ENGINE .... SO YOU WAS THE GASOLINE AND THE A FUEL FILTER/GAS PUMP/DID THE VENTING FUEL TANK TROIBLESHOOTING ..

 

[shiloh87]

Oh ya every things fine, new iggy, carb, fuel line, filter, tank. I built the boat a couple yrs ago.
If I hit rough water a couple good thumps it`ll quit. Start it back up head on if it gets bumpy it`l quit. once it quits, I do due diligence and every things fine(always have my tools and diagnosis tools with me). Calm flat water no issues.
So there`s a fault in the harness or the old original to motor remote. It can`t be anything else, it just took me 3 yrs to come to this conclusion. The motors fresh I`ve only been able to put 70 or so hours on it. Just this bounce of a big wave hit hard and the engine stalls/quits, sooooo, harness iggy circuit. when restoring the engine, all the block wiring was replaced but I cheaped out and didn`t replace the harness, the project budget was done.
If I don`t sell her the next plan will be to stuff a big block in her and have some real fun.
Cheers

 

[Scott Danforth]

I would look at the pertronix.

 

[kenny nunez]

Have you tried removing the cannon plug to spread the male pins that plug into the female engine side of the engine’s harness. Another place to look is the back side of the instrument panel. Try putting your finger on each wire terminal that is retained by a screw or a nut. Your Petronics kit should be able to operate on 12 volts. Rig a jumper wire from the + battery post to the + or bat side of the coil then hit some big waves to try and make the engine stop.
Your boat looks like a very nice Donzi Clone. The last 18’ Donzi I had was scary fast with the 383 MPI @ 70. A real PITA to work on, trust me on that.

 

[QBhoy]

Hi. Have you checked the health of the rectified electrical system these have ? If you still have that system at all. Perhaps you have upgraded her (like most folks tend to), with the more reliable alternator modification kit.

 

[nola mike]

Try wiggling connections/harness when under way to see if you can replicate the problem
Edit: that boat is gorgeous

 

[ROY WILLIAMS]

The fix of that MCM470 engine troubleshooting ? FIXED IT !