Re: Adjusting idle on a 1978 Evinrude 140 hp crossflow motor (model 14083C)
OK, compression is 120 all the way around and I have spark. I tried to time this thing in a 95 gallon tank with my buddy who is a "mechanic." I wasn't sure if using a trashcan would produce enough back pressure and turns out it doesn't. It runs horribly now. I had to trun the idle screw back all the way down to get back onto the trailer. A couple questions I have now...
Big question: I thought I was supposed to check the timing at idle? After reading a manual I bought and also a few threads it seems I'm supposed to check the idle at WOT? How can I do this w/o hanging off the boat at 50 mph? Is there any way to test the timing at idle?
Reeves explains the below in his timing tutorial
NOTE: If your engine has the "Fast Start" feature", you must disconnect/eliminate that feature in order to use the following method. The "Fast Start" automatically advances the spark electronically when the engine first starts, dropping it to normal when the engine reaches a certain temperature.
The full spark advance can be adjusted without have the engine running at near full throttle as follows.
To set the timing on that engine, have the s/plugs out, and have the throttle at full, set that timer base under the flywheel tight against the rubber stop on the end of the full spark timer advance stop screw (wire it against that stop if necessary).
Rig a spark tester and have the gap set to 7/16". Hook up the timing light to the #1 plug wire. Crank the engine over and set the spark advance to 4? less than what the engine calls for.
I don't know the full spark advance setting your engine calls for, but to pick a figure, say your engine calls for 28?, set the timing at 24?. The reasoning for the 4? difference is that when the engine is actually running, due to the nature of the solid state ignition componets, the engine gains the extra 4?.
If you set the engine to its true setting at cranking speed, when running it will advance beyond its limit by 4? which will set up pre-ignition causing guaranteed piston damage! You don't want that to take place.
No need to be concerned about the idle timing as that will take care of itself. The main concern is the full advance setting.
Be sure to use your own engines spark advance settings, not the one I picked out of the air here in my notes.
My boat has a warm up lever...is this a "Fast Start feature?"
If so is he just saying don't engage the warm up lever while timing?
Is he basically saying just time it 4 degrees less than what the manual calls for? On my 78' Evin V4 140 hp it says it should be @ 28 degrees at full throttle....
Does this mean set it to 24 at idle?
To set the timing on that engine, have the s/plugs out, and have the throttle at full, set that timer base under the flywheel tight against the rubber stop on the end of the full spark timer advance stop screw (wire it against that stop if necessary).
I don't quite understand. Does he mean take out the plugs, then move to WOT position, then move the top timing screw all the way until the rubber touches?
I'm sorry but I'm not familiar with timing motors and I haven't had any experience with 2 cycles besides my weedeater, and the 3 mnths I've had this boat.
When we were trying to set the timing in the 95 gal trash can it was at idle and was reading 8 degress, BUT the clip part of the timing light seemed to have broke. We weren't using a spark tester (although I have one). He was just attaching the clip to the #1 cylinder plug wire and shooting the light onto the flywheel and the timing mark was coming back at 8 degrees.
My buddy is bringing his other timing light to fix this but I would like to know how to do it before he comes over as I dont' think he is as much of a "mechanic" as he thinks he is. I'm pissed because I gave him $50 to do this, it was running okay in the can, and so so in the water while it was cold, I immediately adjusted the timing screw to higher idle and it was still running okay. My boat seems to run worse after driving a while as I mentioned in the original post.....
My boat seems to run fine when cold...even after running for several minutes....but when after I drive it hard for 10 minutes or so it starts to want to die at idle. This was happening before and also after I messed up the timing. While we were messing with the top timing adjustment I was having to adjust the idle screw out (lower rpm) to compensate because the more we adjusted it the higher it was idling. At 1st, I thought was good as I thought the idle screw all the way in was a bad thing, as previously mentioned most likely compensating for another issue. The plastic thing I referred to in the pic above is the cam yoke. It seems to be lined up fine.
Could anyone give me a better explanation of how to time, or a thread with more detail?
