149 engine teardown for cam replacement

[Mr Bob]

Thanks for all the advise on my other thread about the broken cam shaft. Thanks to all that responded. It created a lot of interest and a lot of great information was given. At the end of the thread, I was having trouble with starting the engine. It would only start when the ign. switch went from start to the run position. I can't remember if That issue was resolved or not. That is how bad my memory is.
This week I decided that I could take the engine apart and replace the cam shaft. Today, the only thing left in the block is the governor gear and what ever is associated with it. The engine came apart remarkably well. Had a problem with the rear balance gear. It was hanging at the top of the shaft. Could not see or feel any thing at the top to keep it from coming off. Pried it off with a large screwdriver and it came off. The bottom of the cylinder has a small piece missing. (first picture) Something has happened to this engine prior to my owning it. Probably why it has a .010 bore and new piston. I will not put the balance gears back in engine. Top ring has .010 end ring gap. Second ring has a .035 end gap. I would like to have new valve seats and valve guides installed, but so far I have been unable to find a shop willing to do this. One of the members may have a used cam shaft to sell to me.
I believe this engine will be ok to put back together with new rings and a used cam shaft and new crank seals. Going to attach pictures because everyone likes pictures. Thanks for reading this, enjoy the pictures and have a great day.
Bob

[J-Mech]

Valve guides on a K series are seldom wore. Unless you are putting in new valves, don't fool with them.

[Alvy]

Bob I think you need to have that cylinder bored and fit with new piston plus crank checked/ground. Lots of scoring on that piston top to bottom. You can throw it back together with some new Parts but realize it’s a crap shoot and may or may not last. All these old k series have egg shaped bores in them and if it didn’t smoke before it may very well smoke upon reassembly with just new rings. The famous line on here though is that it’s your cub and your money so do as you wish. Btw I think I have a used cam also.

[darkminion_17]

I agree Alvy, but what did you do?
Hehehehe

[Mr Bob]

OK Alvy, Just what did you do????? Sounds like a story here.
Bob

[J-Mech]

I didn't say anything.... because I get tired of saying it. Unless the engine is brand new, a ring job seldom works. Just overhaul it and be happy, happy.

[darkminion_17]

Originally Posted by J-Mech

I didn't say anything.... because I get tired of saying it. Unless the engine is brand new, a ring job seldom works. Just overhaul it and be happy, happy.

[sawdustdad]

I had a K241 that I had the dealer "rebuild" because it was smoking. This was 5 years ago, before I had the confidence to do it myself. Anyway, they said the cylinder didn't need boring, and they replaced the rings. Cost was $800. It lasted less than a year cutting 1 acre every two weeks. So probably 25 hours. Started smoking, piston slapping badly, and blowing oil out the breather cover. Took it back to the dealer and they did it over again, no cost. After that, I rebuilt them myself, and had the local NAPA machine shop do the machining. I think I've done 4 or 5 myself since then.

Anyway, you've got it this far apart, might as well bore it and do it right.

[twoton]

Originally Posted by Alvy

......Lots of scoring on that piston top to bottom.......

That's what I was thinking..

Remember Bob, you're never gonna say, "dang, I wish I had not done it right!".

There's a washer/shim under that governor gear, make sure you save that.

So what was wrong with the cam??? You got any pics of that?

[Mr Bob]

Twoton: The tab that raises the exhaust valve broke off after it bent down and I tried to straighten it. I haven't taken the governor out. Does it have to be timed to the camshaft? Attached a picture, hope it shows up ok.

Sawdustdad: The Napa store close to me says that Napa no longer does any machine shop work. Could you give me the phone# of the Napa that does your work and maybe they can direct me to a Napa near me that does machine work. Thanks, and have a great day.
Bob