Timing questions and worries

[ricohman]

I have been out on the lake 3 times this week in my new to me 1984 Starcraft tinny with its 1984 90hp V4.
When I got the boat the original owner had his ranch mechanic change the plugs and "clean" the carbs" along with drive seals.
It wasn't running very good so I rebuilt the carbs and now it runs very well. Lots of power and I can bring it back to idle where it will putt along happily at 750rpm or so as long as I want it to. It runs an updated VRO pump. The only thing is it needs a bit of fast idle to restart when hot, but it will fire instantly.
Anyway, I have read that some people who do not understand how this 2 stroke works try and bump up the idle speed by adjusting what they think is the idle screw when its actually the timing advance that sets idle speed.
I am worried this ranch mechanic maybe adjusted this on my engine and with to much advance I sure don't want to burn out a piston.
I am still searching for a manual but is it worth my money to drag the boat to the dealer to have them set the timing? It runs really nice. But the risk is on my mind....
I have a garage full of tools including timing lights (was a mechanic in my previous life) but I have read you need to run this motor open to set the timing properly.

 

[interalian]

You think he thought the max advance stop affected idle? Since that doesn't contact anything at idle, I can't see why that would be a worry. You can do the "Joe Reeves" method (sticky above) to be sure you're in the ballpark

 

[ricohman]

You think he thought the max advance stop affected idle? Since that doesn't contact anything at idle, I can't see why that would be a worry. You can do the "Joe Reeves" method (sticky above) to be sure you're in the ballpark

That's what I'm worried about. That stop looks tempting for someone to adjust.

 

[F_R]

If somebody messed with the full advance stop, that could be bad. But the screw that the throttle lever contacts at idle speed is there for adjusting the idle RPM, so don't be afraid of that one. Set it wherever is best. BTW, yes that does affect the MINIMUM spark advance (retard). Idle speed is primarily controlled by spark advance (retard).

 

[ricohman]

If somebody messed with the full advance stop, that could be bad. But the screw that the throttle lever contacts at idle speed is there for adjusting the idle RPM, so don't be afraid of that one. Set it wherever is best. BTW, yes that does affect the MINIMUM spark advance (retard). Idle speed is primarily controlled by spark advance (retard).

Maybe I am worried about nothing. I would guess if it was adjusted it would have been the idle timing.
Thanks for the information.