From: "Mark Smith" To: "Bill Cook" Cc: Subject: UL: Re: ignition timing Date: Tuesday, August 01, 2000 5:51 AM posted to fly-ul for general knowledge,,,, Bill Cook wrote: > > In your reply, you said I the resistance should change (points close?) at > 0.086 BTDC. The rotax manual I have says the points should close at 0.018" > BTDC. Have I read the book wrong somehow or are we talking apples and > oranges? A clarification sure would be appreciated. > > Bill of the Jungle > > PS I have the same problem on 3 engines 377,477 and 503 weird coincidence As I said, if you have two (three) engines with ponts you should invest the time and money for the proper tools such as a flywheel puller, a fan tool, dial indicator and adapter, good ohmeter, to make life much easier. The points OPEN at .086 piston travel BTDC. This is the same for all the engines you mention Just before the point opens, you are reading the resistance of the points which you have the meter attached to, in PARALLEL with the ignition coil and the other set of points in series. After the pint in question opens, the resistance changes to that of JUST the ignition coil and the OTHER set of points. The gap should be set at .015 for both sets with a feeler gauge. The timing should them be measured for bothe sets of points. If they are the same proceed, If not, then reset as they are on the same armature plate and should read the same, even if not the correct timing. To proceed, then rotate the armature plate such that one of the sets is at the required .086 BTDC timing, and then READJUST the other set to get the same .086 BTDC timing. Also, check the clor of the spark. It should be bluish rather than a weaker oragnge when smartly pulled by hand on the bench. If not bluish, then start by replacing some parts AFTER thoroughly cleaning the ppoint gaps by pulling a thin piece of shirt cardboard through them. Dirt will open the points slowly and make for a poor spark. Rusty coils can and do affect the spark quality as do the ends at the plugs. Any grime or soot INSIDE the rubber boot at the plug end indicates a breakdown of the plug end and calls for replacement. When reinstalling the ends or inserting the wires in the coils, always trim an 1/8 off to get a better hold for the screw. And after some practise, the whole scenario above should take mp more than ten minutes,,,,, -- Mark Smith mailto:trikite@evansville.net Tri-State Kite Sales 1121 N Locust St Mt Vernon, IN 47620