GM 350 Distributor

aweimer · Post by **aweimer** » Mon May 30, 2011 10:25 pm

I need your guys suggestion here.

I have one of my 350's not coming to RPM. Couple things pointing to this, one the rust in the site holes for the weights in the distributor is key. The engine is timed perfect at idle. As i power up, this engine requires a lot more throttle to keep RPM in sync with the other engine, thus burning a lot more fuel. WOT is running 3200 tops.

I've rebuilt both carbs, filters, timeing. New shafts, props are balanced, the whole deal. The distributor will advance if i grab it and turn it, it snaps right back, but i'm not sure if its advancing while under way.

So I have options. Replace with stock breaker, mercruser distributor here.

http://www.marinepowerservice.com/Boati ... year/0.cfm

Or put in this mallory breakerless marine one for less money. I wanted thoughts on this option, any use these before? Summit is a good company, use them for many hot rod parts.

http://www.summitracing.com/parts/MAA-YLM624AV/

prowlersfish · Post by **prowlersfish** » Tue May 31, 2011 6:29 am

I would stay with the merc. it is set up for you engine

aweimer · Post by **aweimer** » Tue May 31, 2011 9:38 pm

RH or LH rotation. Question, looking at the engine manuals i have for the 255 mercs, both distributors rotate clockwise with different firing orders. So is it the same distributor on each engine?

There are options for Clockwise or Counter Clockwise replacement distributors.

Paul · Post by **Paul** » Wed Jun 01, 2011 9:59 pm

Aaron,
The cam shafts and distributors rotate LH regardless of crank shaft rotation on the 350. To run the crank shaft RH, the timing chain set is replaced with two mating gears which allows the crank rotate in the opposite direction from the cam. On the RH rotation engine, the cam shaft profile and the firing order is also different.

As far as the distributor goes, why not simply replace the breaker plate assembly with a Sierra electronic conversion kit. For a little over $100 you can upgrade your old breaker dist to electronic. Installation involves removing the breaker plate assembly, installing an electronic pick up plate, slipping on a magnetic ring over the breaker cam and then resetting the ignition timing.

http://marineengineparts.com

Hope this helps

aweimer · Post by **aweimer** » Thu Jun 02, 2011 8:38 am

Thanks for the info.

I have the Mercruiser distributor and the weights/springs are sealed and you cannot order replacements for them. I see rust on the springs/weights on this engine and its resulting in a lack of WOT RPM and fuel economy issues.

I spent some time on the phone with Mercruiser yesterday while they dug through micro fish to provide part numbers for "factory" replacements. Well needless to say they stopped making that stuff years ago.

I ordered a Mallory YL624AV for replacement. Should be here today and I'm looking forward to installing it over the weekend and resolving this issue.

http://www.jegs.com/i/Mallory/650/YL624AV/10002/-1

prowlersfish · Post by **prowlersfish** » Thu Jun 02, 2011 12:09 pm

I am sure you made the right choice , I did not realize you had a breaker point system when I posted

aweimer · Post by **aweimer** » Thu Jun 02, 2011 3:22 pm

Yeah i opted for the points distributor replacement too. I will let you all know how it goes this weekend.

Big D · Post by **Big D** » Thu Jun 02, 2011 10:23 pm

Curious, if buying a whole new unit, why did you opt for points again?

aweimer · Post by **aweimer** » Fri Jun 03, 2011 12:16 am

I didn't want to have to mess with the ballest and stuff. Points are cheap and easy to setup. Never had issues with them.