Ignition Timing Question Merc 165 IL6

[jimfj]

Hello All,

After doing a complete tuneup of my 165 IL6--points, plugs, condenser, rotor cap and checking the plug wires I started and ran the boat in the water. Everything checked out except for what I would call a miss at idle 650-700 rpm.
I borrowed a neighbor's timing light to check the timing. It was off the scale on the tab-I am guessing 12 BTDC. I am supposed to be at 6 degrees BTDC.

Running on muffs I adjusted it to 6. It ran worse-lots of vibration and just didn't feel right-hesitation when I gave it throttle. Went to 8, much improved. 9-10 very nice idle, very smooth. Revved it up in gear and out seems to be okay.

Is this an indication of something out of wack?
Does this have anything to do with the fact the engine was made in 1976, never rebuilt, low hours-650, and the leaded fuel was different back then?

Any help is appreciated. I have not been able to water test this after the timing adjustment.

Jim

 

[ziggy]

Re: Ignition Timing Question Merc 165 IL6

jim, ya haven't talked about what yer dwell is at. 31*-34* would be apropriate. dwell effects timeing also. if yer dwell is set proper ya could also look fer dwell variation. where dwell vary's is an indication of worn distributer bushs. these might some things for ya to look into.....what's yer compression too. ya might run that check ontoit.....since ya were usein yer neighbors timeing light. be sure it aint one of them that have an advace dial on it. if it does set it to 0...........

 

[jimfj]

Re: Ignition Timing Question Merc 165 IL6

Thanks Ziggy,

I am in the process of locating a dwell meter and I'll check that.

Jim

 

[bruceb58]

Re: Ignition Timing Question Merc 165 IL6

If you adjust your dwell, you will have to adjust the timing again.