timing issues

[bluehonda600]

I used a timing light and got ten degrees when it should be 20. When I try to adjust it it only move max 2 degrees advance and two retarded. Is there any other way to adjust the timing besides the porkchop looking thing next to the carbs? Or am I doing it wrong? Motor is a 1999 mercury 90 hp 3 Cyl. Please help!!!!!!!!

 

[CharlieB]

Re: timing issues

First thing is to get yourself a factory service manual, that will direct you to the timing linkage and how to set full advanced timing.

Remove the spark plugs and attach the wires to a spark adaptor.

Remove the prop so that you don't bash a shin as the prop spins.

Connect a remote starter button to the starter relay.

Set the throttle control shifted into Forward gear and open the throttle all the way.

Turn the ignition ON

Connect your timing light to the top cyl

Crank the motor with the remote starter button and observe WOT timing.

 

[hkeiner]

Re: timing issues

I suggest that you do all the link and sync steps. If a previous step/setting in the link and sync process is incorrect, it will affect the accuracy of the max timing adjustment too.

 

[mcdgary]

Re: timing issues

CharlieB doesn't the prop have to be under a load at WOT, i.e., in the water?

 

[CharlieB]

Re: timing issues

It isn't an easy task to hang on the back of a speeding boat and set timing at WOT.

Removing the prop and setting timing while cranking with the spark plugs out is much easier and safer.

Some manufacturers manuals specify setting in this manner and some also specify adjusting 2 degrees less than max to allow for full RPM spark advance.

This is why it is always so important to have the FACTORY manual, Chiltons, Clymers, Seloc, are not always as detailed as the OEM Manuals.

 

[hkeiner]

Re: timing issues

As further clarification, only the IDLE speed timing is set with the motor running in gear out on the water.