Re: F-4 Magneto Question

Posted by Roger Mills on February 18, 2007 at 07:18:30 from (71.213.68.215):

In Reply to: F-4 Magneto Question posted by Tom43 on February 18, 2007 at 06:13:18:

While Magman rebuilds mags and is lurking about the forum, and knows all. Some info that may clear up things in general: some mags do not have an impulse coupler but MOST do. It retards or delays the spark and the snap increases the output so it will fire when you crank it or spin it with the starter. General rule is that the impulse should snap at or just after TDC so the engine will not kick back and break your arm or the starter. When the impulse is spinning fast enough it 'kicks out' and the timing reverts to normal. Normal can be a manual advance/retard lever or fly weights that move outward and advance the spark with rotation speed/RPM, OR rarely, both BUT sometimes neither. Different engines have different timing requirements and these are part of the design of the ignition system for that engine. The initial timing of any engine is part of that design--if they use the impulse snap as the criteria then it assumes that the points are set to proper gap AND the correct mag is installed and working correctly. If they use the points, usually a distributor ignition, then it is when they just open and you use a meter or something like it to see when they "just barely" open. If they have a manual advance lever it should be in the full retard or specific 'start' position and is specified in the tune up specs from the manual. If no specs exist for a given engine then this info can get you close without breaking something when you try to start it.

Replies:

• Re: F-4 Magneto Question Dave Allgire 08:53:23 02/18/07 (0)

Add a Reply Name: E-Mail: Subject: Comments: Optional Link URL: Link Title: Optional Image URL: Email Notification: If you check this box, email will be sent to you whenever someone replies to this message. Your email address must be entered above to receive notification. This notification will be cancelled automatically after 2 weeks.

TRACTOR PARTS	TRACTOR MANUALS

We sell tractor parts!  We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today. [ About Us ]