1988 Johnson 110 cant advance timing far enough.

[AEROCOOK]

Hi all. I have a 1988 Johnson 110 and for whatever reason, I cant advance the timing to the required 28 degrees BTDC. The timing rod adjustment block is set at the maximum position and all I can get is about 25 degrees BTDC. To me, a logical solution would be to bend the rod a little bit to effectively shorten it and allow the timing base to advance a little bit further. Any thoughts on this? Is there a better or easier fix?

 

[Bosunsmate]

you actually only want to set this at 24 deg btdc

 

[AEROCOOK]

you actually only want to set this at 24 deg btdc

Thanks for the reply. Is this because of modern fuel? I've heard about timing spec changes on the Merc inline 6 motors because of modern fuel but didnt know it applied to OMC crossflow V4s.

 

[Bosunsmate]

Thanks for the reply. Is this because of modern fuel? I've heard about timing spec changes on the Merc inline 6 motors because of modern fuel but didnt know it applied to OMC crossflow V4s.

the answers in here http://forums.iboats.com/forum/engi...4008-joe-reeves-wot-timing-procedure?t=228183
I always set mine conservatively, five below whats needed as i much prefer to lose a touch of top end than burn up the pistons

 

[AEROCOOK]

Sorry, maybe I'm missing something here but according to Joe's timing method, the net result is timing at spec. (set at 4 less than required and when running it gains the 4 back) So just to clarify, when using Joe's non running method, all I can get is 21 BTDC

 

[Bosunsmate]

Sorry, maybe I'm missing something here but according to Joe's timing method, the net result is timing at spec. (set at 4 less than required and when running it gains the 4 back) So just to clarify, When using Joe's non running method, all I can get is 21 BTDC

oh ok, thats not right then, dont go bending anything.
have you checked the flywheel key? I just check at tdc that the pointer on the engine is at tdc on flywheel

 

[AEROCOOK]

oh ok, thats not right then, dont go bending anything.
have you checked the flywheel key? I just check at tdc that the pointer on the engine is at tdc on flywheel

Flywheel key is good, I just replaced it. I will make sure the pointer is set right.

 

[emdsapmgr]

At what rpm are you mesuring the WOT timing? It idle, or at 5000 rpm's?

 

[Fed]

The timing rod adjustment block is set at the maximum position

The retainer block post is eccentric and may be rotated for three additional rod locations.
(From the manual)

 

[AEROCOOK]

At what rpm are you mesuring the WOT timing? It idle, or at 5000 rpm's?

I'm using the Joe Reeves method, I was looking for 24 degrees which would equate to 28 degrees at WOT. Could only adjust to 21 degrees.

 

[AEROCOOK]

The retainer block post is eccentric and may be rotated for three additional rod locations.
(From the manual)

Yes, I have it rotated for max advance and the rod is positioned in the furthest hole forward.
I'm using the factory manual for all adjustment procedures except the Joe reeves timing procedure of course.

 

[AEROCOOK]

I checked the pointer and it was set right, All I can think is that there must be play in the linkage or the rod has been bent open at some point. I went ahead and bent the rod very slightly and the WOT is perfect now. Started the motor and checked base timing at idle and it is 4 degrees as it should be.