Rob,
Thanks for the offer. If I have a problem I will certainly look you up. For now, I think I am going to try the smallest advance bushing with the weakest springs. As was said, I can easily change it if it doesn't work.

I've got mine set-up with the black bushing and the light blue springs. Initial timing set @ 18 for a total advance of 36 degrees. Works great for me.

Definatly use the black bushing. Modified engines need more initial timing for a decent idle. If you have a large cam, you may want to lock the dist.

My engine builder likes to use one of the lightest springs and one of the next lightest. He has found in the marine environment that when using two of the lightest springs the advance doesn't always return.

MSD makes a start retard unit, but it is not approved for marine use. If it was, I would lock them out and use the retard unit. This way you don't have bushings that wear or springs that rust.

I run locked timing 32 with MSD hardware. I have 540,s Blown. Starting creeps when hot. Sometimes I have to click batterys to both. (Optima Bluetops).

My plan this season will be a MSD 121-8984. this is a retarder.
which backs down timing below 700rpm. Jegs has them for 89.00.

Gerry

Thanks guys. I will try the black bushing first.

I run mine locked as well. The small wire springs are fragile and I have seen them break over time. I have always run stock merc starters with no problems. My current motor is a 10:1 598 and the motor in my last boat was a 13:1 496.

I have the ability to have a start retard or not. I run the MSD Digital 6 Plus.
I have experimented in both "modes".
I presently run fully locked with a 9.2:1 comp ratio without the start retard feature.
I know it is not USCG approved but it is not mounted in the engine bay. Actually, it is fully "potted" like the marine unit.

www.msdignition.com/ignition_18_6520.htm

What I like about locking the timing is how quickly the motor fires. As soon as I touch the key it starts. I don't know what is worse for the starter cranking it over a couple of revs with less timing or loading it a little harder locked in and having it start immediately?

My buddy at MSD put it to me this way if your boat burns and you don't have the marine uscg MSD box the insurance could deny the claim.I didn't take the chance over 50-75 bucks