1983 150 mercury timing issue

[drm11900]

Going by the book I pulled the white/black idle stabilizer wire. Pulled all the plugs but #1 cylinder top starboard side, adjusted the idle stop screw as directed, hooked up the timing light and cranked it over....and the primary timing says 2 deg atdc. it's supposed to be 11 atdc.

Alright then I have a problem so I adjust the Primary pickup screw and best I can get is 9 atdc before the trigger runs out of adjustment.

Why is this? What should I do at this point?

Thanks, Dennis

 

[j_martin]

Re: 1983 150 mercury timing issue

What book?

Sorry, but it varies with the engine. Book idle timing is a starting point. Set it where it idles at the right RPM with the throttles fully closed.

 

[drm11900]

Re: 1983 150 mercury timing issue

Clymer Manual but the sticker on the engines carb cover agree's with the book.

Should I set the Timing as you suggest with the stabilizer wire disconnected?

 

[drm11900]

Re: 1983 150 mercury timing issue

Geez what gives? I just checked Max timing, it's supposed to be max 18 btdc at cranking speed but it's off the chart! Somewhere in the neighborhood of past 24. 24 is the last mark on the flywheel.

Any Idea's here?

 

[j_martin]

Re: 1983 150 mercury timing issue

Did you use a depth gauge to set the timing pointer?

 

[drm11900]

Re: 1983 150 mercury timing issue

I tried rigging up a dial indicator. I found TDC but then the manual says to turn the flywheel counter clockwise to 1/4 turn past the 0.462" mark. Then back to exactly 0.462" and set the pointer. I run out of stroke on the indicator when I get there. I have to turn the flywheel a long ways to get there.

This is what it's like in automotive terms. When I pull the distributor on a chevy and put it back in one tooth off I am unable to get the timing set due to running out of stroke for the advance. Now this has no distributor but I have had the flywheel off as well as the stator and the trigger but I'm pretty sure that it's all back how it belongs.

The motor runs fine WOT but chugs on idle. Hole shot is a little weak. I am simply trying to do a link & synk here but it's really got me confused.

I'm heading out now to set the idle with the muffs then off to the lake. I'll check the idle there while in gear. I'd had alot of electrical issue's with missfiring and such and have not changed the plugs untill now.

 

[drm11900]

Re: 1983 150 mercury timing issue

Thanks j_martin for chiming in and trying to help me out with this.

Much appreciated

 

[CharlieB]

Re: 1983 150 mercury timing issue

It is critical to set the marker at the .462

The flywheel does not have to be backed off a 1/4 turn, but it MUST BE backed off at least .500 so any possible slack in piston/rod/crank is taken out before coming up to the .462 where you set the timing indicator.

If you have a two piece flywheel it is possible that the hub and outer and not in sync, which is another reason setting the .462 point is critical. When the dial indicator is at .462 and the outer flywheel is way off, you will have to unbolt the hub and re-index the outer to properly align the .462 mark.

 

[drm11900]

Re: 1983 150 mercury timing issue

Thanks CharlieB

Can you awnser this for me? If #1 is at TDC should I be able to see the timing marks on the flywheel? As it stands no marks are visible.

 

[drm11900]

Re: 1983 150 mercury timing issue

OK back in the garage. Here's what I've done now.

Found TDC then backed off ccl past 0.462" then came back up on it and pulled off the flywheel cover. I'm 180 deg off from the 0.462" mark so I unbolted the hub moved it 180deg's. Put the cover back in place. Reset the 0.462" from TDC and now the pointer is about 1/4" away from 0.462".

Now I'm off to readjust the pointer so that it's inline with the 0.462" on the flywheel and then to recheck the timing......fingers are crossed.

 

[j_martin]

Re: 1983 150 mercury timing issue

Nothing works better than just doing the procedure?

 

[drm11900]

Re: 1983 150 mercury timing issue

Back from the lake. Still chugs at idle but only after it's warmed up.
Here's something interesting. I pulled the covers to check for miss firing and while I had it opened up it ran fine, in gear, in neutral and had a great hole shot. After I put the covers back in place it mysteriously started chugging again.

I noticed alot of exhaust around the engine...I think it's getting inside the covers and choking out the carbs.

Anybody else experience this? How can I keep good air at the carbs at all times?

 

[drm11900]

Re: 1983 150 mercury timing issue

Took the covers off this morning and made a discovery.

This boat and motor has been resurrected after 6 years of neglect. Mice have had their way with it. I found they had chewed through the cowl gasket on the starboard side just under and behind the carbs intake. I believe this is allowing exhaust into the cowl area causing poor idle and bad hole shot.

 

[CharlieB]

Re: 1983 150 mercury timing issue

Sounds like you have it sorted out, a combination of a prior owner incorrect assembly of the flywheel and the neglect/mice, you'll soon have it purring again.

Like J keeps telling everyone, 'When all else fails, read the book, follow the directions, and it comes out good.'

You might also take a look at the air inlets of the covers, they sometimes get restricted with mouse nests.