max spark advance rod not making contact with stop

[Thumpbass]

I just got a '78 85hp cross flow. I haven't had a chance to fire her up yet but I was tinkering around with the motor and noticed that when I push the throttle lever (by hand) that the throttle valves open completely but the max advance spark rod doesn't make it to the stop screw...it advances may be half way but stops way short of making contact with the stop. The spring in the throttle lever appears to be working and retracting as it should. The previous owner had it linked and synced before I bought it so the adjustment stop screw should be right (looks like it's at least in the correct vicinity)...I'm just wondering if something is sticky or if something may have gotten shaken, loosened or broken in shipping (well packed on a pallet). Any thoughts ?

 

[Thumpbass]

Re: max spark advance rod not making contact with stop

BTW forgot to mention....I can move the rod forward by hand and make contact with the stop (retracts on it's own as it should) but it just won't make it when using the throttle lever.

 

[R.Johnson]

Re: max spark advance rod not making contact with stop

On the control arm bolted to the block, there is a spring cup molded into the arm holding a quite strong return spring. When you push the throttle back, are you over coming this spring? It takes a fair amount of force when working the trottle by hand.

 

[Thumpbass]

Re: max spark advance rod not making contact with stop

I would guess so because the throttle shaft roll pin on the carb is showing the throttle valves to be in the open position, and the lower section of the throttle lever is making contact with the WOT stop screw. Is it possible to use enough force to open the throttle valves completely but not advance the max spark rod fully?

 

[R.Johnson]

Re: max spark advance rod not making contact with stop

No, the spark advance should reach full advance against it's timing adjustment screw before the carb's go fully open. Unhook the link arm to the ignition stator, and see if it is rotating freely. If it is, you will have to go over the sync & link again, some where it is out of adjustment.

 

[Thumpbass]

Re: max spark advance rod not making contact with stop

looked at it a little more and it seems that the wiring on the oposite side may have been tucked into the wrong retaining clip causing some resistance to the stator. after feeing it up, it is making it to the stop but not as freely as I'd like...I think I'm headed in the right direction

 

[i386]

Re: max spark advance rod not making contact with stop

I ran into a similar problem when I swapped powerheads. I tucked a wire into the wrong clip and did what you described. Correcting that and sync & link adjustment fixed it.