Carb plastic cam roller question

[Scaaty]

Working on a motor for a neighbor. 84 4hp Rude Twin. Does the plastic butterfly cam follower just snap on? Can't see any clip in the IShop diagram. Seems the butterfly adjustment is all the way out, and also the ignition advance would seem to be way too advanced at part throttle (to 3/4) as the butterfly is barely opened until all the way over to the stop. I'm getting what sounds like a death rattle at about half throttle(in the water) at a certain halfish throttle position, and above, or below, it goes away. I can't find anything loose that could make the rattle, and was thinking it might be pre-ignition. 120 PSI in both jugs, and do not think its piston rattle (?), or a rod, which I think would be constant. Any help greatly appreciated

 

[OBJ]

Re: Carb plastic cam roller question

Roller just pops off Scaaty.<br /><br />The timing is easy to set, look on the cam for a reference mark. When this mark is centered on the roller, the throttle plate should just start to open. Two screws hold the cam to the ignition plate...losen them to adjust the cam out or in until the setting is correct..

 

[Scaaty]

Re: Carb plastic cam roller question

Got it...thanks a bunch!