Cub 123 - Fix? Part out? Replace?

[Fred's 123]

Yep... just pulled out the hardcopy of my service manuals this morning. Guide swapping seems straightforward. Same with checking the valve seats. I'm interested in tools and methods for reaming the guides, assuming there's hand reamers out there for this.

The bigger unknown is the installing and setting of the valves. I'm working under the assumption I should replace these valves, as the exhaust valve was sticking and likely a little burned, according to the PO. I don't have any valve seat grinding tools. I can hand lap, but then the question is, using what? The old valve? The new valve? What compound?

Thanks, guys!

[IACubCadet]

If you are going to lap the valves in, make sure you use the new ones. Automotive stores USUALLY carry lapping compound for grinding valves. I don't have any valve grinding tools, but I have overhauled 10+ engines by lapping in new valves and they all have run sweet for me.

The hardest thing I have found in putting the valves back in is putting the keepers back in. Small fingers and hands are great for that job

[Fred's 123]

Cool. Thanks. I'll pull that original motor apart tonight to get a look inside, and then get my guides, valves, compound, gaskets, etc. on order. If anyone has a favorite suction cup/spinny tool, let me know quick! Otherwise, I'll just order the first I find.

Thanks!

[MrGitrdone41]

Originally Posted by Fred's 123

Cool. Thanks. I'll pull that original motor apart tonight to get a look inside, and then get my guides, valves, compound, gaskets, etc. on order. If anyone has a favorite suction cup/spinny tool, let me know quick! Otherwise, I'll just order the first I find.

Thanks!

It is nice to have the suction cup thing.lol I have not used one on my motor i just press my hand on the valve and move it. To put the valves in go to Harbor Freight and buy a GM door spring comp. It's 8$. It works great for Kohler valves.

[Fred's 123]

Cool. Thanks! I had two small pliers-type spring compressors from my father or grandfather, and they worked well for getting the keepers off tonight, but I don't think they'll be too convenient for getting the keepers back on. I'll have to check out the HF one.

The valves are out! Valve seat spec is 0.032" to 0.063", and exhaust valve is close to 0.032" minimum, which is great! Intake valve seat is probably closer to 0.045" (measuring by eye), which is still serviceable. I'll just have to be careful lapping in the new valves.

Old exhaust valve and port area had a bunch of what looked like white paint buildup. Knowing this motor was only run 1965 - 1983'ish, I'm assuming that's lead? I scraped it clean as best I could.

Exhaust valve was actually TIGHT in its guide, to the point of sticking a bit, whereas the intake valve had just a hair of play. I'm not sure how to go about measuring the guides, but knowing the guy who owned this before me (very smart, and very meticulous), if he says the exhaust valve guide needs replacing, I'm doing it. In fact, I'm just going to do both, and replace the valves while I'm at it.

Shopping list is as follows:

Valve guides
Valves
Front PTO bearing
Carb gasket
Head gasket
Oil pan gasket
Points gasket

I think I can scrounge the still-new breather element and gasket, points, plug, etc. off the engine I just broke.

Anything I'm missing? Do I need to plan to replace keepers, springs, etc.?

Will pull the oil pan tomorrow to check out the bottom end before I commit.

Thanks!

[Fred's 123]

Where do you guys buy your gasket kits, etc? I need the shopping list above filled, and would like to place an order today.

Thanks!