34scarab

Several posts ago I recall running across some discussion about "locking the timing" to full advance to help at idle speeds. Can anyone shead some more light on this?
Doesn't this kill the starter, trying to start at 34°?
I am currently dialing in my new motors and am having difficulty with them at idle speed around docks and stuff (read other boats). When I put them in gear, I need to goose it some to keep the rpms from dropping to low and stalling the motor. maybe this is due to the cam selection. I am running Comp cams 11-433-8 which is supposed to be a little rough at idle, but unless I bump the idle speed screws up but that isn't good when attempting to put them in or out of gear, clunk!
Any ideas of comment would be great before I go tear something up!

Gary Anderson

Not sure what kind of carbs you're running, what engines, or what ignitions. But yes, starting a hot engine with 30+ degrees of advance can be difficult to start. A lot of racers run 2 switches. One cranks the starter, the other turns on the ignition.
You should check your idle mixure screws and tune your carb according to specs. Weber/Carter AFBs can be tuned to max rpm + 1/2 turn, then adjust idle speed.
Chaeck your initial/total advance. Make sure that's OK. Check your plugs for fowling. If they are carboned, go to a hotter one. If only carboning at idle, crank your idle screws in 1/2 turn more.
Check the simple stuff first.
Gary

jaroot

or i reckon you could add an MSD or similar start retard to it (if everything else is properly taken care of for adjustment)... some of the boxes come with it built in... others it is an add-in to the circuit...

my digital 6+ has a 20 degree start retard built in if i so desire to utilize it.

34scarab

I am running holley 830's. They have 6.5 power valves front and rear. Jetting is currently at 86/94. Dart single plane intake. Msd 6AL igintion. Gen IV blocks, .030 over, 4.25 stroker crank, pro Topline heads, 9:1 .
Total advance is set at 34°, inital is around 12.
The fuel may be too old as they sat for almost 1 year while I fixed them. Maybe just flowing some clean fuel thru them will help. Haven't burned thru the old stuff yet.
Tough to tell/read plugs witht he MSD.
It seems no matter how fat I go, they usally seem pretty clean. I am planning on jetting up a size or two for this weekend and do some jetting runs to see where I am at.

razor1115

Don't use the idle speed screws to bump up the idle....You need to adjust your idle mixture screws UNDER LOAD at idle to get the maximum vacuum reading at the carb. Now, your idle may still be too low, but do not adjust the idle speed screw; it may just be choked for air. I you open the idle speed too far, it meters off the primary circuit and not the idle circuit resulting in poor gas consumption and loading up. There should be an adjustment for the secondary throttle plates. If they are all the way shut, open just enough to fit a small wire (like a tag wire) in the gap. This should speed up the idle and does not introduce more fuel to the system. Open until you find your desired idle in gear is reached (probably 750 to 800). Then take out of gear and check idle - should be around 1000 - 1100rpm which is acceptable. If too high or you want a little lower, adjust secondary throttle plate in gear again (open for higher idle, close for lower) to slightly drop idle then recheck rpm out of gear. You can do all this by yourself with the boat in the water tied to the docks (keep you from running into things )

Zack

Bigger cams require a little more tuning at idle to get to perform half way decent; especially to keep from ramming the docks when the darn thing dies or is giving you fits

Crazyhorse

It might help to get your initial timing up around 15 degrees. With MSD it's a simple change.

formula31

Ive used the crane Hi-6 ignitions locked, they are multiple fire and at idle, fire +/- 20 degrees. So locked at 36, the first fire happens much earlier. If I remember, over 2000 rpm it goes to single fire. You have to set your igntion timing at full in, usually over 4000 because the timing light wont work at idle on these multiple discharge igntions.

I think the MSD's do the same thing.

Ha, I never thought about it but maybe the name came from Multiple Spark Discharge. Who knows?

RedDog382

I'm running 510 c.i. Sterlings with MSD ignition and MSD distributors locked at 34 degrees. No problems cranking with gear reduction starters (I think they are Tiltons), even when warm. Idle at ~900 R.P.M., in gear @ 500 R.P.M. without bogging. Carbs are Barry Grant with four-corner idle. I wasn't sure about this setup when they proposed it either, but these motors purr around the dock. Sometimes you do get what you pay for!

Crazyhorse

I know KAAMA is running the Crane Hi-6M boxes on his 540 engines, 9.67:1 compression, with his timing locked at either 32 or 34 with no problems at all.

34scarab

How does one go about "locking" this distributer to full advance? I know mine has the centrifical weights.
I also considered changing the amount of advance to the minimum, MSD distributers allow you to do this by changing out the bushings in the distributer.
Hope I still have these somewhere...
If I did this, I could still run 34° total, but run a hight inital.
Maybe???