how to adjust timing on a 50HP, 3 Cyl, 1988

[mcgurk34]

my engine manual procedure requires setting the timing with the engine running at 5500 RPM in forward gear. How can you do that safely? I don't have access to a test tank and the motor is mounted on the boat. Has anyone done this with some kind of barrel or garbage can? The idea of trying this on the water seems very dangerous.

 

[michael lyons]

Re: how to adjust timing on a 50HP, 3 Cyl, 1988

I have a 95 60 Hp 3cylinder merc. The timing RPM's from the manual says 550 in forward gear, That is the idle rpm, 5500 is wide open throttle. Suggest check the book again may be a misprint...

 

[mcgurk34]

Re: how to adjust timing on a 50HP, 3 Cyl, 1988

I checked my Clymer's manual and it states "Start engine and run in FORWARD gear at 5000-5500 RPM. Point the timing light at the flywheel and adjust the maximum advance screw to 23 degrees BTDC." There is no setup for the timing at idle speed. Frankly I'm not sure how to do this with the engine mounted on the boat. Flying across the harbor hanging over the stern with a timing light in one hand and wrench in the other is not something I look forward to trying. How critical is the timing adjustment on these engines?

 

[Troy_from _Oz]

Re: how to adjust timing on a 50HP, 3 Cyl, 1988

Just remember to secure all of your tools before you start off - you'd hate them to fall overboard while screaming along at WOT like that <br /><br />Just jokin. Im not sure of how its meant to be set on your motor - but im sure that one of the more knowledgeable folks will be along to help out before too long. Hang in there.

 

[rickdb1boat]

Re: how to adjust timing on a 50HP, 3 Cyl, 1988

Take it to the ramp and back it in the water just enough to get the water pick-ups on the engine submerged and leave it on the trailer. Make sure it is secure. Run it up and check the timing. Or, another way is to move the timing plate to full advance and crank the engine over while pointing the timing light at the mark. Set it 3-4 degrees retarded(20 degrees in your case) and it will be real close when you run it on the water. Much safer this way!

 

[mcgurk34]

Re: how to adjust timing on a 50HP, 3 Cyl, 1988

Thanks RB. That is a great idea. Use the whole harbor as a test tank. I will be careful to make the boat very secure to the trailer before running up to WOT! This method should be a lot safer than what I was invisioning.<br /><br />regards

 

[mcgurk34]

Re: how to adjust timing on a 50HP, 3 Cyl, 1988

RB,<br />I just re-read your reply and noticed the second method you suggest which simply cranks over the engine and uses a timing light to set the stop.(Not actually running). This is even easier than hauling the boat down to the boat ramp. Does this method yield acceptable results because there is no vacuum or mechanical advance on this engine, so there is no need to spin the flywheel at 5000-5500 RPMs? This is basically setting the stop on the spark advance linkage with the throttle linkage at WOT. It seems to me like this should be a completely valid way to set the maximum spark timing on this model. Any opinions from the other experts.<br />Thanks and Regards<br />JM

 

[Virago85]

Re: how to adjust timing on a 50HP, 3 Cyl, 1988

on my 77 175 it says to remove all but #1 plug and crank over set mark on flywheel to notch in cover this is at 0% tdc and that should give you 15% btdc at wot same with primary set to notch and it will give you 8% atdc