Yep that's what you need in order to get the correct parts.

Maybe, this is a dumb question... Do you guys use any type of gasket sealer, when installing head gaskets, or just make sure everything is nice, and clean, and flat?

Hoping to get back to the Cub soon, but Momma's Minivan needs some suspension work this week...

No sealer. This is a good how to get your heads nice and flat.
http://www.onlycubcadets.net/forum/s...ead.php?t=5656

Well, it's been a couple weeks, but I've been slowly but surely making progress on the 1641. I got the heads, and rest of the engine pretty well cleaned up. changed the head gaskets, and Valve cover gaskets. Three of the push rods had quite a bit of play, so I adjusted them. The choke was bent down, and not opening back up all the way, and I got that straightened back out.

I put it all back together, and then changed the oil. Started up great, but then started trying to backfire. I checked the PTO, and it seemed to run fine.

So, before it was bogging down, to the point of shutting off, under PTO load. Now, it seems to run great under load, and it will full on backfire with the PTO off. Could this be a carb adjustment, that I somehow messed up, when putting everything back in place? Could it be the push rod adjustment?:bigthink:

Check the push rods again and the carb.

I haven't had a chance to get back to the cub yet, but was reading some old posts around here that got me thinking. I'll readjust the valves, but could this be a timing issue? I did turn the motor with the heads off while cleaning up all the carbon...

And how would that have knocked a magneto ignition out of time? :Unknown:

I have no idea. That's why I was asking. I don't completely understand how these engines work... Yet.

It's not out of time. Ignition, or valve. It's fixed, non adjustable.

Worked at the cub some more today. Whether the valves were an issue, or not, they weren't close to where I should have had them, so I adjusted those.

I ran it for a while with the PTO on, and sure enough, when I shut the PTO off, it was trying to backfire. It didn't shoot any visible fire out the exhaust, and was happening at a slower rate. I went about trying to trouble shoot. Mind you, as this thread already shows, I don't know much about these machines. When I pull either spark plug wire, the backfire seems to go away, I don't think that tells me anything. So, I go to take air filter back off to look at carb, while running. With the air filter off, it seems to run fine. I just purchased this one around January, If I recall correctly. I cleaned it up as best I could, and put it back on. It still backfires some.

I guess my question is do I need to still adjust the carb, to let more air, or less fuel through? If so, do I just start at standard settings, and tweak from there?