Adjusting The Timing, Let me Make Sure I've Got This Right..

Sat Jul 20, 2013 3:53 pm

Our Cubs are rated to fire at 16 degrees before top dead center at 1800 RPM.

So I'm going to go make a mark on the outside of the pulley that's aligned with the punch mark on the face of pulley. Then I'm going to go down (if you're looking into the pulley from the carb side) 16 degrees, or 0.644", and make a second mark (perhaps a mark that most of you with the later pulley have already). When this puppy is running, the timing light should be firing when my second mark crosses the pointer. And this would make sense since my second mark would cross the pointer before my first mark does (and this would agree with the BTDC). Then I adjust the distributor from there until it does.

I think my issue is my timing light is smarter than me. I bought a used digital light off eBay in order to get the tach feature. My engine was running anywhere from 1780-1810 so I was really pleased. But when I hit the decrease button to go down to -16, it went to 180. So I took 16 from 180 and went down to 164. I was trying to get the mark to line up, but quit when it started sounding terrible and it was obvious from the distributor that I had gone too far.

Looks like the old school way is still the best way.

Re: Adjusting The Timing, Let me Make Sure I've Got This Rig

Sat Jul 20, 2013 6:59 pm

Dennis,

The manual says 16 degrees BTDC @ 2,000 rpm.

Re: Adjusting The Timing, Let me Make Sure I've Got This Rig

Sat Jul 20, 2013 7:34 pm

timing a C-60 with a light is easy to do but performance wise I have never hand any luck doing it that way. My preference is to advance the timing by ear under a heavy load. usually with 59" woods. I advance till i hear the valves ping then back off till pinging quits. I shut down to make sure it restarts like it should. The further you can advance timing on any engine with the valves not pinging the more torque it will develope. My old friend George willer told me that many years ago.

Re: Adjusting The Timing, Let me Make Sure I've Got This Rig

Sat Jul 20, 2013 8:11 pm

Clark,

Timing by ear is what I have been doing. And believe me that it sounds what I think is wonderful. But I can't make heads nor tails of what the timing light is telling me. I am interested in maxing out the torque though, as getting the C-2 belly mower spinning better is one of my hopeful outcomes of this timing adjustment.

The following pictures speak for themselves. She sounds good where she is, but somehow or another it looks like I'm approximately 90 degrees off. I've checked multiple ways that I've got the clip on the #1 wire. You can see where I had to digitally adjust the light to get the 16 degree mark to line up with the needle. How much can you twist the distributor and the engine keep running? It seems like there's probably 30 degrees of adjustment without much noticeable change.

Like I said, she sounds just fine. Drives around good. Won't spin the belly mower for nothing. I'm just trying to dial in the timing as it's what's best for the electronic ignition. Then put this baby to work !

Image
Image

Re: Adjusting The Timing, Let me Make Sure I've Got This Rig

Sat Jul 20, 2013 8:30 pm

You may want to adjust on the mower a bit. Make sure that the advance weights are free and set it by the light to TDC at a low idle. If it advances about an inch past the TDC mark [ if you do not have the second mark] it is OK in the timing department.
Boss

Re: Adjusting The Timing, Let me Make Sure I've Got This Rig

Sun Jul 21, 2013 4:46 am

Good post Clark....