Timing adjustment

General Boats and Motors
1

Before last summer’s endless carb/timing issues, I had a motor that always pull started on the second or third pull, always. It is a '92, 25 merc, and (until last summer) has given me problems only 3 times in its life. Now when it tries to fire, it yanks the pull string out of my hand. I assume the timing is off. It will eventually start and run well. However when I try to start it again, even hot, it slams against itself. The shop I have taken it to just can’t get it right and tells me “that’s just the way it’s supposed to be, or it’s bad gas…” They seem like good guys who want to do right, but I really feel like I have been taken to the cleaners this summer.

Does anyone know how to adjust it? It should be easy, but I am not sure which screw/arm to turn. I am thinking it should be the timing linkage that connects to the choke arm. It would be 12 here: http://www.boats.net/parts/search/MercuryMarine/0d149846/367/30/Throttle%20and%20Shift%20Linkage(Tiller%20Handle%20Shift)/parts.html.

If there is anyone out there that can assist or point me in the direction of a quality shop/person I would greatly appreciate it.

2

A lot of the smaller motors have a valve that is open when you are pulling it to let off some of the compression. When the motor fires the force of the rotation of the motor closes this valve so you have more power. It sounds like that valve might be stuck closed on your motor.
Mr Hardware

3

If is runs good once it’s started I wouldn’t think it’s a timing problem. Off timing would make it run rough I think.
Mr Hardware

4

that would make sense… now to find that value.

5

that motor doesnt have a compression release valve that i am aware of
idle timing is different that WOT timig
timing is connected to the throttle
as soon as you begin to advance throttle, you are advancing the timing
if the idle is set to high, to maybe compensate for another issue, then the timing will also be artificially advanced and could easily cause the issue you are describing
call me and i will be glad to try and help

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