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Sierra electronic distributor for 318

They show it as a [FONT=&quot]Mallory YLM579AV[/FONT] replacement.

The M in the YLM = magnetic, of which means that it's a VR unit.
VR = Variable Reluctor.

I will take VR triggering over photo-eye triggering any day.
 
Okay this is confusing. Clicked on the Sierra, $536. Searched for "318 electronic distributors" on Amazon and got a lot. Prices ranging from $50 to $600. Looked at a few but saw no mention of VR. Did see M in a few of the part numbers. So do these auto distributors (LA) work on the marine LM? At what price range do they become junk? I have a '71 LM 318 with points.

Thanks, Friz
 
I'm not a fan of the new Sierra branded products.....they aren't what they used to be.

Whatever you buy, make sure it is marine rated (SAE J1171 sticker on it).

Mallory used to be the go to aftermarket source but those assets were sold a while ago.....you may get lucky and find a Mallory "NOS" unit somewhere.
 
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Okay this is confusing. Clicked on the Sierra, $536. Searched for "318 electronic distributors" on Amazon and got a lot. Prices ranging from $50 to $600. Looked at a few but saw no mention of VR. Did see M in a few of the part numbers.
Back when Mallory was still a Mallory company, they had begun phasing out the YLM ( YLM = VR = variable reluctor ) in lieu of the YLU ( photo eye ) units.
This was a "shot in the foot" in my opinion. VR is trouble free and always has been!

I do see some vendors stating that the Sierra unit is a direct replacement for the YLM series, but it is NOT!
They are apparently substituting with the YLU!


So do these auto distributors (LA) work on the marine LM?
The automotive advance curve is incorrect for Marine use and could lead to engine damage!
The automotive units are NOT ignition source protected.
Vacuum advance is ineffective for the Marine engine and is not USCG approved.


At what price range do they become junk? I have a '71 LM 318 with points.
Prices on the new electric systems have become outrageous.
If you are willing to routinely replace the contact points and are good at adjusting your dwell angle, you will be OK until you find a good price on the unit that you want.

Thanks, Friz
 
Okay this is confusing. Clicked on the Sierra, $536. Searched for "318 electronic distributors" on Amazon and got a lot. Prices ranging from $50 to $600. Looked at a few but saw no mention of VR. Did see M in a few of the part numbers. So do these auto distributors (LA) work on the marine LM? At what price range do they become junk? I have a '71 LM 318 with points.

Thanks, Friz


Just my opinion here. You can do yourself a favor.
If that OEM point distributor has intact original mechanical advance springs and is functioning properly, have it spun on a distributor machine and archive the curve chart information for future use. If you get into it further have the advance springs "
replacement"
matched for spares.

And if you do that, the you can also help others by posting the advance curve here.
 
Dave, if memory serves me, you are a Chrysler guy.
As you know, for years now no one here to date has been able to find and post a Chrysler Marine OEM ignition advance curve.
We have tried and tried, and NO GO! We can find BASE advance all day long!
So as long as the existing curve is good, what you are proposing is a great idea!


As for the flyweight return or governing springs, these are of very light values, and they do vary from manufacture to manufacture.
For the car guys, changing these springs may be no bid deal!
However, for the Marine guys, this is so critical. One small change in spring value can make a large difference in the curve.
This is why I always suggest using a Distributor Machine to verify.
 
Honestly if you have an old points distributor and the advance weights and springs are OK, and you can still get tune up parts for it, stick with that. It will take a bit of maintenance but over all there is just less to go wrong, what do you do with an electronic distributor, when the OEM makes the module inside NLA?
I have a points distributor in my old OMC and kept it all this time, in fact I picked up a brand new points plate and springs right off this site, as spares and actually picked up a spare OEM distributor off of ebay. I would never tell someone who has a good points distributor to get rid of it for some made in Ch!@#% electronic distributor, if that is what Sierra is selling.
 
I run the Pertronix 1581 electronic ignition with a 40011 Flamethrower coil, having a 1.5 Ohm internal resistance in both of my marine 318s, which eliminates the ballast resistor and they perform well. I always had a little trouble starting the port engine but after this upgrade the problem went away.
 
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