Name that engine. I've done some research and found that Petco was an inbetween company betwee Quadra and US Engines. Since I got this engine without a muffler or carb I am in search of these items but need to know what size this engine is. It has RD502 and 20800 and Made In Canada embossed on the back side of the head. Is it worth getting this old engine running or should I just sell it for parts?

It looks to my untrained eye to be an OLD Quadra 35 or 40. Especially old because it is the original points version. What size is the prop that is mounted on it? That can be a minor clue. An 18x6 and it is likely a 35. An 18x8 could go either way. 18x10 and it is a 40. Some say you can tell by the piston rings. One ring is a 35. You can get a much newer Quadra, or US Engine which is much the same, with CD magneto ignition (no points) off the RCU market place for about $150. Maybe twice the money you will have to spend to get the parts you need, but you would have twice the engine.

Have fun which ever way you go!

Bedford

I had made it as far as identifying it to be either a 35, 40 or 41. And while I know there is a conversion kit to eliminate the points I think that puts it over the top as far as money spent to make the ole girl sing again. Incedentally the prop is an 18 x 6-10 Pro Zinger non-constant pitch prop. So that is really no help as it covers the entire range of props you mentioned.

From my experience a 18 X 6-10 pulls more like a 18 X 10 than a 18 X 6

actually, looking at it you might be able to get around the points by installing a homelite coil instead of the stock one, I upgraded a chainsaw from points that way, the flywheel had the magnets in the same position so I used the stock flywheel and just replaced the coil. I say homelite because that's what the mounting pattern looks like to me, if you go to your local mower shop you can probably get a used junk power head for like $5...

The internal components would have to be in near perfect condition to justify doing anything at all with it. Clean it up externally and put it on a shelf would be my best recommendation.

It looks as though the vertical set of muffler holes are wobbled out to a certain extent

Actually the top one is gone, completely broken away.

The threads don't look too good on the horizontal set of holes. If that is the situation, you best just set it on the shelf

Why? The points system is straight forward and as reliable as the old CDI systems that were sold for the Quadra 35 & 40 cc engines. At least you, the operator/owner, can fix the points if they wear out of adjustment. The CDI system must be replaced in toto most times when they fail. Also, hand starting is much easier with points as is obtaining a low steady idle.

Just my $.02.


Ed Cregger