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timing question for 350 / mallory unilite

This question has come up a few times with no certain answers on timing for idle for a 2006 carbed 350 with Mallory unilite dist. I had a lot of work done recently that involved new plugs, wires, re-set timing, etc. Before the work I was happy with my 1-1.1 mpg that fastJeff was helpful enough to steer me into. Now, I'm back to .8mpg. No Barnacles, but some slick algae on the bottom, props are spotless. My concern is that the mechanic set my timing at 12deg at idle, and that sounds too advanced for me. No spark knock when close to WOT, but my efficiency went backwards. Any thoughts?
Steve
 
The book says 26 degrees of advance at WOT. with 12 degrees of initial, that means the distributor adds another 14 degrees. Don't have the factory book but do know that most unilites come with 24 degrees of "advance" built in (easily changed with their kit).

On timing advance, more is better, but only to the point that the engine can use it. Especially true with the marine applications as the load on the engine is huge.

Did you do the before-after comparison the same day or several weeks apart? That algae, even though slick, adds a whole lot of surface area to the hull. Means more work which equals more fuel, all else being the same. The other item, at least on the east coast, is the air temp has really risen early this year. Hotter air means less density which means less output from the engine.
 
Look for a dirty flame arrestor, old gas, extra stuff being carried, etc.

Mine is a slug each time it sits for a few weeks, but a good blast up the Elk River and all is well again.

Jeff
 
Alright MakoMark, so what you are saying is that my initial timing should be 2deg, if the mallory has not been adjusted from factory settings (which I'm almost sure it never has). 2+24=26. Maybe my increase in fuel consumption is due to this. If it is 10 deg off at initial timing, does that mean I would need to adjust the carbs to get my idle in check and would it now be difficult to start? (hard starts were the reason for the mechanic in the first place). And if I want to leave initial timing at 12deg for easy starts, I can buy the kit and lower the advance to 14 if I can figure that out, right?

The two tests, were not done the same day, they were weeks apart, and the algae could very well be causing some of this. I thought it was a dirty bottom at first and that is when I got under it and found no Barnacles, just a little algae.
 
A note to everyone boating in the heat affected East: The heat wave we are experiencing has caused rapid underwater growth, especially barnacles on prop blades. It doesn't take many of these things to drag a boat's performance down substantially.

If your boat is slipped, and its not performing up to specs, check your props and bottom. And, no, you can't wash barnacles off by running the boat (or power washing either). They have to be scraped off.

Jeff
 
I can't confirm the barnacle but can state the algae/slime stuff on mine "blossomed" when I checked her yesterday - looks like the "dog days" have arrived early.

On the advance, not exactly. I'm saying that the default state of a unilite provides 24 degrees of timing advance. As far as what Crusader specified them to have, don't know but that should be in the service manual. You could always call and ask too. You need to measure the advance to know what the distributor is providing. If you need to adjust the advance, yes, the spring and weight kits are readily available.

The timing advance curve can be changed but you need to verify any changes you make. The curve provided from the factory works ok for most installations; some can do better with a few adjustments but don't expect Crusader to help if you mod things. if you do change the curve, be very careful....with the load on a boat engine, you may not get a second chance.
 
Hey last hour...I had some similar problems with the same motor only 2008 year.Just for the heck of it check your coil to see if it requires an external resister or not.Mine did not,but it did have an external ballist resister. Would barely run after I replaced the plugs and gapped them correctly.Good luck!
Michigander
 
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