Rotary valve question

[Matt_martians]

Hello,
I got a 1995 spx I'm replacing the crank seals on. The rotary valve is between .010 and .012 thick. It won't fit the .012 feeler gauge in. I'm wondering why this barely is in spec. Because it seems like the gap would thicken if it was out of spec. I'm thinking of replacing the rotary valve bc it's rusty and I dropped it. I don't think I scratched it when I dropped it, but I think I'd be safe in replacing it. But I am wondering why the clearance is so tight. Is it bc of the rust.
Also how do y'all hold the crank in place to remove the PTO and the magneto? I've seen people use rags but I don't trust it. I'm about to use my drill press to make a holder and I was wonding if anyone has done that before, and if there's any threads of people making their own puller.
Here's some pics of the RV and the cover.

 

[mikidymac]

First you can’t replace the inner crank seals and those are typically the ones that fail.

How is your rotary valve rusted? It’s stainless steel and if water got into the engine the crank is toast.

Finally the PTO should be removed before taking the engine apart so that you can lock the rear piston and unscrew it. The front flywheel is removed with a flywheel puller and impact wrench.

 

[Matt_martians]

First you can’t replace the inner crank seals and those are typically the ones that fail.

How is your rotary valve rusted? It’s stainless steel and if water got into the engine the crank is toast.

Finally the PTO should be removed before taking the engine apart so that you can lock the rear piston and unscrew it. The front flywheel is removed with a flywheel puller and impact wrench.

No clue as to how it got rusted honestly. It ran decently when I took it out last time(I took it apart soon after I took it out). I pressure tested the inner crank seals to 3psi and it held pressure overnight. But my magneto housing was full of oil when I pulled it off. And thanks for the advice. I'll pull it apart and see what the crank looks like.

 

[mikidymac]

Engines should be tested to 8 psi.

 

[Matt_martians]

Engines should be tested to 8 psi.

Alright. Also do you have an advice on how to remove the PTO flywheel? Should I bolt my engine down to the workbench?

 

[mikidymac]

It is easier with the engine secure.
Rope or a block of wood in the rear cylinder to lock the crankshaft.
Then lots of heat on the PTO and I use a chain wrench on the outside diameter of the PTO and typically a couple wacks with a heavy hammer will break them loose.

 

[Matt_martians]

It is easier with the engine secure.
Rope or a block of wood in the rear cylinder to lock the crankshaft.
Then lots of heat on the PTO and I use a chain wrench on the outside diameter of the PTO and typically a couple wacks with a heavy hammer will break them loose.

Is there a way to do it without heat? I don't want to ruin my inner seals.

 

[mikidymac]

The heat will not be anywhere close to the inner seals.
It might damage the outer seals but those should be replaced anyway.

I really don't think you can get a stubborn one off without heat. I have had to use heat on all the ones I have done.

I use Mapp gas and heat until the paint starts to turn color and smoke. You are not getting it red hot or anything.

 

[Matt_martians]

The heat will not be anywhere close to the inner seals.
It might damage the outer seals but those should be replaced anyway.

I really don't think you can get a stubborn one off without heat. I have had to use heat on all the ones I have done.

I use Mapp gas and heat until the paint starts to turn color and smoke. You are not getting it red hot or anything.

Thanks for the info. Time to run back to the auto parts store to warrenty out this bad boy and try again on my flywheel. Peep the homemade tap for my mower crank next to the broken bolts lol

 

[mikidymac]

That is the flywheel not the PTO so don't use any heat on it.
Don't thread the bolts in too far or you will destroy the stator coils.

A quick hit with an impact wrench and a good puller should pop it off easily.

 

[Matt_martians]

That is the flywheel not the PTO so don't use any heat on it.
Don't thread the bolts in too far or you will destroy the stator coils.

A quick hit with an impact wrench and a good puller should pop it off easily.

Yeah I know, I was going to replace both seals. That was an AutoZone (OEMTOOLS) puller. I broke it with an impact. I ran it down pretty hard with a powerful impact. But I think OEMTOOLS cheaped out with the bolts. I got a new puller, and if these break I'll go to the hardware store and get some grade 8 bolts. I read somewhere as a general rule of thumb to not screw it in more than 10 times.