Logo

LM318 reverse rotation with Mallory distributor

Donthemon

New member
Good day gentleman,

I am at my wits end , I have been working on ( automotive Mopar or no car) engines all my life this marine engine is kicking my @ss. I purchased the boat 2 weeks ago and it ran ok on the test run the prior owner took me on. Ok not great , starboard engine a little rich , both engines a little effort to start nothing I didn't think tune ups wouldn't fix.

I am 99% positive this is the reverse rotation engine , its the Starboard engine connected to a Vdrive .The starter turns the engine clockwise looking at it from the flywheel ( bow ) , counter clockwise looking from the harmonic balancer ( stern ). It has the required thrust collar under the distributor. It turns in the opposite direction of the port engine.

The problem began when I got ambitious and wanted to clean up the engine wiring harness. One of the prior owners removed the original Chrysler electronic ignition & distributor replacing it with a Mallory distributor YLM. I removed the even #'d cylinders plug wires to give me more room to work. I failed to mark them because I downloaded the Chrysler Marine Engine Manuals from one of the other threads on this site which has both the normal rotation and reverse rotation firing order.

Long story short I screwed something up with the plug wires and could not restart the engine. So I took the distributor out of the engine and rotated the engine by hand , found the timing marks on the flywheel & verified the #1 cylinder was at TDC with both valves closed felt in the cylinder with a pencil the piston was in fact at TDC.

Checked the oil pump/distributor drive gear/shaft. The slot in the gear was pointing 12o'clock to 6o'clock. I reinstalled the distributor and the rotor was not pointed towards 12o'clock position as I expected but 9o'clock. I thought that was odd but I just figured #1 on the cap would just be 90deg off as I was accustomed to. As long as I wired cylinder #1 to that location on the cap and followed the firing order it would be fine.

All I get is back firing out of the carb. I though was 180deg out so I raised the distributor slightly so I could rotate the rotor 180deg. Same problem. I definitely have fuel , oxygen and heat everything necessary to promote combustion. Just apparently not in the correct order and or ratios.

I've done hours of googling on this engine and distributor combination. So far the only steps I overlooked is when I reinstalled the distributor is I failed to align the reluctor and pick up for the electronic ignition directly across from one another. Nor did I check the air gap of the magnetic pick. When I return to the boat later this week I plan on checking the gap and aligning the pickup.

Could this affect the timing so much that I wouldn't be able to start this engine? Or is there something else I may be missing?

Any help would be appreciated.

Thank you.
 
That was it!!! Reconfirmed #1 cylinder TDC , went to a local speed shop bought a TDC locator tool & harmonic balancer timing tape. Brass feeler gauges checked the air gap. Set the pick up for the #1 cylinder located under the rotor and reluctor directly across from one another. Wired the plugs to the rotor in reverse firing order and amazing fired right up. If i cranked the starter for 2sec it was alot.
 
Back
Top