1982 80 hp idle question

[profgolf1]

I can't get the idle under 1000 rpm.
Throttle plates are closed.
I have a gap between the idle stop screw and the stop.
There is also a small gap between the primary cam and the carb cluster pin
Timing is 5deg. atdc
If I advance the timing the rpm goes up

 

[ondarvr]

Are you saying you can't back the timing off any further?

 

[profgolf1]

specs call for 2 deg btdc to 2 deg atdc for my serial number
I think I can retard it more
are you saying to retard it more than 5 deg atdc?

 

[ondarvr]

You just set the timing to where it idles best, the actually timing doesn't mean much. Although if you are way out of spec it may mean something else is out of spec too and you end over compensating for the first issue.

 

[profgolf1]

You may be right.
Back when I first registered for iboats there was someone who had written a real good link and sync for an engine like mine.
I can't find that.
I have searched for posts with timing, link and sync.
Any idea where I can find it

 

[profgolf1]

Did a google search for the link and sync page and found it on the first page.
Timing 2deg atdc in the water and in gear.
rpm about 650 in gear, 950 in neutral, btw my tach showed about 250 rpm high, used a manual tach to find that.
Max timing is 27 deg.
Tweaked the idle mixture and all is good

 

[jimmbo]

That 2 degrees is probably referring to the Primary pickup point used in the link and sync. As ondarvr said idle speed is set by retardation of the timing. The actual setting will vary from engine to engine, and even by prop selection

 

[Tjy7510]

Yes the idle, timing and rpm are all affected with the boat in the water. That's why it's called a test run. If that fails and the motor has reed valves like mine they may need to be replaced? Older engines with reeds don't last forever.