Falcone magneto removal

[GTM®]

Hi Folks, My Marelli magneto (MCR4) yield a very weak spark when kicking over the engine so I’ve decided to bite the bullet and have it “rebuilt” and re-magnetized, new condenser, etc. Now I only have to remove it and so have a few questions on that topic. I did note that Patrick Hughes has done just that so perhaps he can give me some helpful hints.

I’ve detached all of the oil lines and the cable for the decompressor. So question (1) is, do I remove the oil pump before trying to remove the timing cover.? (2) do I also remove the decompressor “lever” that the cable attaches to before the timing cover? I did remove the nuts/washers which hold on the oil pump but the pimp wouldn’t budge. Maybe it’s just the gasket compound that was used but I don’t want to break anything.

With all of the screws removed, the timing cover wouldn’t budge either. It could be just “glued on” very tight or I have to get the oil pump off first?

Patrick mentioned that the gears all came out when he took the cover off. Why was that? Is there away to keep them in place when taking the cover off?

All help is appreciated.

Bob A

 

[GTM®]

Don't need to pull the oil pump or decompressor. Hopefully yours is cleaner!

You will probably need to put a blade in the joint to separate the timing cover. The cam often comes off with the timing cover unless you hold it in place with a gasket scraper or similar when pulling it away. It's good to know your starting point 'cause the timing marks can be haphazard!

SCI SED

 

[GTM®]

Oil pump and decompression lever can stay in place and will come away complete with the timing cover. Likely the cover has some sealant holding it. Judicious angular rapping with a plastic or wooden mallet should do the trick.

As soon as the timing cover seems loose, reach behind the center portion with a kitchen knife or similar to hold the camshaft gear into
the engine while you further remove the cover. Often, if you just pull the cover, the cam comes with it and then you lose timing register with the crankshaft gear. Hopefully your gears have good marks. Mostly not.

Look for small angle grinding on the side of one or two gear teeth to denote the timing point.

The pictures sent in by SED are good. No need to remove the oil pump. When you remove the cover, the intermediate (middle) gear may “stick” to the cover by suction. The bearings are plain bearings and the shaft and gear may stay on the engine side if you are lucky or may come away with the cover. Try a thin blade to hold the gear back but this is difficult. Do not panic if the gears come out, you can work out how to put them back. The intermediate gear has the cams for the valves on the back of it which must be timed correctly. My timing marks were non-existent so I put the piston at TDC and then found the point where the cams are both at their lowest point and put the gear back.. You have to put the push rods and cam followers in the right position so the gear goes on. Both push rods should have slack in them if you have got it right Take note there is a thick washer at the back (engine side) to hold the cam followers away from the casing. This dropped out on mine when the gears came out and it would be easy to miss it. There wan no gasket on mine so I sealed it with Hylomar. Any liquid gasket will do. Once you have the intermediate gear in place you can set up the timing gear for the magneto. All a bit tricky but just requires patience. Be sure to set the magneto at the right height and also with clearance on each side of the shaft before tightening the strap.

Patrick H
Fremont CA

 

[GTM®]

Can you check the position of the thick washer, in the parts catalogue it is shown between the rockers to stop them rubbing together. When I assembled mine without the washer in this position the rockers rubbed where the pushrods engaged as the rockers are wider at this point than at the bearing on the shaft.

Brian A

 

[GTM®]

Yes correct I must now check mine again.

Patrick H