1994 Johnson setting timing on muffs???

[Fishjustin87]

I have a 1994 115 Johnson model# J115TLARC on my boat that I would like to verify the timing on. Had some help trying to verify it and I believe the timerbase screw was messed with. Boat was on muffs and at idle and the ground wire for wire for the fast start feature still connected. Could not get more than about 6 degres BTC so he started messing with the timer base adjustment. I know this probably messed it up and I want to make sure it's set properly. Does the boat have to be in the water to check the timing? Can the Joe Reeves method be used? If so what should my steps be to check both idle and WOT timing? I do not believe that anything was messed with other than the threaded rod coming from the timer base but he could have messed with the screw below that sets the stop. Any help would be greatly appreciated. To my understanding this is a 90°. I really want to get out on the water

 

[havoc_squad]

There is no "fast start feature" on the crossflow motors. There is the primer solenoid which supplies extra fuel to the carbs, this replaced the choke.

What are you trying to do?

1. set the cam follower pickup timing?
2. set the maximum timing advance?
3. set both of these?


Someone has gratefully posted the link and sync video from OMC a long time ago on Youtube for the V4 crossflow motors:

https://www.youtube.com/watch?v=RhsCVTA7U5M


I think this applies to most after 1980 but I cannot say for certain.

First, make sure the cam follower is operating per what the video says starting at 7 min 0 secs in the video.

Timing adjustments depend on the timing mark being correct.. As long as TDC of #1 piston is at that mark, leave it alone.

Second, at 8 mins 30 seconds, it covers the max timing advance adjustment procedure for the 86-88 V4s. Then 89 and later models.

At 10 mins 43 seconds it covers the cam follower pickup timing.


If you don't do the Joe Reeves max timing setting method, the engine has to be on the water under load or on a dyno at the specified RPMs.

Idle speed adjustment is the last thing in the process. All other steps have to be spot on before doing this.

Make sure to put the proper throttle cable pre-load after each idle speed adjustment is made to ensure the idle speed will stay set and not go too high because of cable slop/play.

You are aiming for close to 900 rpms or less idle speed while out of the water on muffs. In water under load rpms around 700 rpms.

 

[Fishjustin87]

I am looking to verify it all. Thanks I appreciate the input

 

[Fishjustin87]

Havoc_squad that video should help me out to verify the link and sync. Without having a prop wheel, I would like to use the Joe Reeves method to set the maximum timing advance. Can you walk me through the process?

 

[havoc_squad]

Just to be clear/transparent, I have never actually yet performed the max timing myself yet either on the water or the Joe Reeves method.

Why, because I only had to re-do the placement of the cam follower after doing a carb job. That as far as what I have needed to do at that time.

However, in order for me to make sure I knew what I was doing was correct, I had to study the OEM service manual for the ENTIRE link and sync procedure.

Only experts who truely know what they are doing can skip around on certain steps to the important step(s).

Link to the Joe Reeves method topic: https://forums.iboats.com/forum/engi...edure?t=228183

After you understand the details in the service manual and compare it against the instructions for the Joe Reeves timing verification method, you recognize it is the same procedure except for three key differences:

1. Joe Reeves method of checking timing disables spark on all the spark plugs by grounding them except for cylinder #1, which uses a spark gap tester hooked to a ground. This is the plug wire you have to get a timing gun pickup on.

2. Joe Reeves method of checking timing removes the spark plugs to keep the starting RPMs as high as possible. It might be possible to do it with them in, but it will drain the battery faster.

Keep in mind there is the danger of gas vapors from the spark plug holes, so you need to move anything away that might cause a spark away if you remove the plugs.

3. Joe Reeves method degree of checking the timing is 4 degrees lower/less than the actual engine running timing. If Joe Reeves method shows 25 degrees BTDC, in reality it will be 29 degrees BTDC.

The max timing adjustment method mentioned in the video is the same, regardless if you do Joe Reeves or on the water under load at the specified service manual RPM.


Just to be clear about idle speed, you make rough adjustments to get it "in the ball park" after getting the cam follower timing properly adjusted. Low enough RPM so that it will idle well and shift safely in the water under load.

Then when everything involving the link and sync is 100% verified, you can play with the idle speed adjustment to get it perfect.

 

[havoc_squad]

After thinking about it more on the spark plugs and fire safety, I would recommend avoiding taking them out if at all possible.

Only take them out as a last resort for this test and only after you have solved all fire safety hazards to perform the test with them out.

 

[racerone]

If you drain the carburetors first you would not have to worry about a fire hazard.----You also would not need to wear a parachute if you drain carburetors first.

 

[Fishjustin87]

Racerone I have not had the chance with the weather to get out and mess with it yet but could I just remove the fuel line with it running to burn off the fuel in the carbs. Should note that this has a by passed VRO and is running premixed. Also what is the reason for the spark plug gap tester on cylinder 1. I understand grounding out 2 3 and 4 but still dont understand the spark tester on cylinder one

 

[Fishjustin87]

My plan is to check the link and sync and then use the Joe Reeves method to set the WOT timing to 25degrees and then put it on the slough with a friends help and fine tune the Wot timing on the water via a harness rope. Sounds dumb but want to be sure everything is exactly where it should be