V4 throttle cam alignment

[wayneo99]

1983 v4 115
I have the motor running and basically doing well. I am woring on the timing and linkage.

pick up timing and idle speed in gear is set to 4 degrees and 750 rpm

my question is with the throttle cam, which has to alignment markings a "start" and another mark. which one does the plastic knob line up with at idle or when it makes full contact with the cam?
the carbs are fully closed and idles smooth.

secondly the idle return stop rod is about 1/2 from the block when idling at 750 with a pick up timing of 4 degrees, it looks as if the adjustment screw really does nothing because its too short to reach the block at 4 degrees so i have the throttle cable adjusted to bring the idle back down to the proper rpm and timing


as far as WOT timing its all set.

any thoughts or picks of the throttle cam alignment?
thanks

 

[wayneo99]

Re: V4 throttle cam alignment

anyone?

 

[emdsapmgr]

Re: V4 throttle cam alignment

The process you are into is called the sync and link procedure. It's pretty detailed and is best explained by the original service manual, where they show illustrations along with matching test. I highly recommend working from one when doing this procedure if you want to get it right. That factory manual will indicate which mark the roller should line up to. When at idle, you should be able to slip a piece of paper between the cam and roller. (no pressure on the roller at idle.) Setting the idle to 4 degrees timing is a good place to start (as an approximate/temporary adjustment)-but it may not be where you need to wind up. You set the spark advance lever idle screw this way: Dunk the boat into the lake. It should be floating at it's normal level. Warm up the engine. Detach the throttle cable at the engine end. Start it and shift by hand into forward gear. Set the idle screw so that the engine idles at 650-750 rpm's. Don't worry about what the idle timing degrees are. (Idle timing degrees will vary for each and every boat and engine due to prop pitch and how deep the engine's exhaust is under water on your boat.) Reattach the throttle cable-you may need to turn the thumbwheel in order to get the cable postioned/adjusted correctly when the engine is idling. As a final adjustment, I'd probably pull the airbox cover to be sure that the carb butterflys are level (completely open) at WOT.

 

[wayneo99]

Re: V4 throttle cam alignment

yes thats exactly what I have done and its running and idling great.
idle timimg comes in at 4 degrees and the idle rpm is 750 in gear
sounds and runs good so far.
thanks