1989 Evinrude 120 HP looper - Re-manufactured Power Head

[REDDOG185]

I first posted about this project (using almost the same thread title) right about a year ago with initially a carb rebuild question. I got the rebuild project done in the fall of last year and took it out on its maiden voyage on 11-7-20. Hopefully I am able to attach a video. In any event, I was very pleased, but a little concerned about a timing issue. I took it out once more before it got too cold and wet for the winter and this weekend revisited the timing issue in my "test tank". The reman power head instructions directed that the max spark advance be retarded two degrees from spec. Setting that in my "test tank" at 4500 RPM is no task for the faint of heart, but regardless, if my timing light is working correctly, the timing mark never did get to 16 degrees BTD, much less the spec of 18 degrees. I was even running out of room on the adjustment screw to advance it any more and was concerned about the potential harm of advancing it too much in view of the instructions with the power head and my concern about the accuracy of my readings. I would really like to take it to a good mechanic with these old boats for a fine tuning, but I have no clue if such a mechanic still exists anywhere near me. I am using a test wheel I got off ebay - which was represented as the correct one, but the number of my required test wheel isn't stamped on it anywhere, and my test tank is a 150 gallon water trough filled almost full. The test wheel did fit the prop shaft perfectly. Anyone had this issue of getting a retarded timing reading trying to check the max spark advance? If my video posts and if it has volume, you can hear that it sounded pretty good last fall. That said, I am still breaking it in, so I never really went above 3500 - 4000rpm on the water. Just enough power to get to plane. Any thoughts would be appreciated.

 

[REDDOG185]

Bump for reconsideration. I just knew Racerone or Fazbullet would have some words of wisdom or at least tell me what I did wrong;(

 

[ct1762@gmail.com]

you can see the timer base, and know how it functons correct? if its not advancing properly, fix whats binding. now, the timing. did you set the timing pointer correctly? the tmer base has to be all the way forward, so give it full throttle briefly, then back it off 3/4, the timing should still be all the way advanced. this is the proper way to set a better cruise speed on the water, btw as it helps gas mileage greatly. also, are you using a digital timing light? if so, make sure its set on 0 dwell angle. you don't need to do it this way , though. simply take a marker or nail polish to highlight the timing you need (if its 16 degrees WOT, mark the 12 degree mark), pull the plugs, and advance to WOT. hit it with the light. adjust as necessary by screwing the high speed stop as needed. i don't think 2 degrees of timing needs to be taken out for break in, but thats just me.

 

[racerone]

At home.-----Drain carburetors.-----Have your assistant turn prop by hand and give it full throttle.------Turn key on.-----Use a remote starter switch at the solenoid.----Crank and check timing.

 

[REDDOG185]

you can see the timer base, and know how it functons correct? if its not advancing properly, fix whats binding. now, the timing. did you set the timing pointer correctly? the tmer base has to be all the way forward, so give it full throttle briefly, then back it off 3/4, the timing should still be all the way advanced. this is the proper way to set a better cruise speed on the water, btw as it helps gas mileage greatly. also, are you using a digital timing light? if so, make sure its set on 0 dwell angle. you don't need to do it this way , though. simply take a marker or nail polish to highlight the timing you need (if its 16 degrees WOT, mark the 12 degree mark), pull the plugs, and advance to WOT. hit it with the light. adjust as necessary by screwing the high speed stop as needed. i don't think 2 degrees of timing needs to be taken out for break in, but thats just me.

It looks like I am getting two different lines of thoughts between you and racerone, which is great, and if I understand your instructions, you offer two alternative methods. I can see the timer base, it does not appear to be binding. I did set the timing pointer correctly. It is a digital light. My basic timing inductive light gave up the ghost and I replaced it with a new digital. I am not as comfortable with it as my old one yet. So I have not used the advance feature and have kept it on 0 setting and just used it as a basic timing light. One question about your first method method for checking it. You say "give it full throttle briefly, then back off 3/4." Do you really meant to back off 3/4 to only 1/4 throtte, or do you mean to just back off to 3/4 throttle? One question about your second method. Since you said to pull the plugs, it obviously isn't running, so after advancing to WOT, I assume that to hit it with the light, I am cranking the engine so that the flywheel is turning and the light is firing, correct? Ostensibly a stupid question, but I want to be sure I understand. Finally, the reduction of 2 degrees timing is what the rebuilt power head directions stated were mandatory. I guess one last question, 16 degrees is with the reduction and you say to set it at 12 using the second method. If I go ahead and set full advance of 18 degrees, would that be 14 degrees using your second method. Thanks for your help and I hope these follow up questions aren't too much trouble.

 

[REDDOG185]

At home.-----Drain carburetors.-----Have your assistant turn prop by hand and give it full throttle.------Turn key on.-----Use a remote starter switch at the solenoid.----Crank and check timing.

This sounds very similar to what ct1762 suggested as an alternative except instead of draining the carbs, he directs removing the plugs and he does not mention turning the prop by hand. One question for you, using your method, do I set it on the actual 16 degrees specification? (ct1762 recommended setting it on 12 to achieve 16 using his similar method.) Thank you for your help too and if you would respond to my follow up questions, I would appreciate it.

 

[Faztbullet]

Put your test wheel on, take to lake and leave on trailer. Run WOT and set timing. As posted make sure timer base is free to rotate and wiring looms not restricting it .

 

[REDDOG185]

Put your test wheel on, take to lake and leave on trailer. Run WOT and set timing. As posted make sure timer base is free to rotate and wiring looms not restricting it .

I had debated this wondering if maybe I wasn't getting enough water through the prop to provide sufficient load. Thanks for your help.

 

[REDDOG185]

I did a little more research on this timing issue. It appears that ct762's advice is pretty much what is frequently referred to as the Joe Reeves method of setting the advance timing on Evinrudes/Johnsons and racerone's advice is very similar. My goal was to do this setting it on 12 degrees BTDC, which I did. A video hopefully is posted below. I then planned to confirm the setting with the test wheel on the ramp as suggested by Faztbullet. Unfortunately, after doing the cranking method, but before trying to confirm it running on the trailer using the test wheel, my brand new timing light quit working. I am now waiting on the warranty replacement. In any event, I went to the lake yesterday and tried out the boat for the first time this year. It ran great except it seems to have lost some punch on the hole shot in comparison to the first trip out last fall after completing the re-build. I am wondering if perhaps the timing is too much retarded. Anyone have an opinion on whether that would that have that effect on the hole shot? Sounds good once it gets above 3000rpm see second video (it was windy- sorry re sound.) Thoughts are appreciated.