149 engine teardown for cam replacement
 

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

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

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.

I agree Alvy, but what did you do?
Hehehehe

cam replacement
 

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

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.

:biggrin2:

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.

That's what I was thinking..:bigthink:

Remember Bob, you're never gonna say, "dang, I wish I had not done it right!:bash2:".

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

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

149 cam
 

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

I use the NAPA shop in Richmond, VA. Talk to Karl, 804-321-7467.

Bob, the governor gear is driven by but not timed to the camshaft.

Are you using the Kohler Service Manual?

Do yourself a favor and find a good machine shop and have them do the work. Most definitely get the crank measured if you can’t do it yourself. The last one I took apart was .008 out of round on the rod journal. Yes these little engines are expensive to rebuild but in the end it will be worth it. Any automotive/performance shop should do the work or be able to direct you to a shop that will. If you’re really desperate I can give you an address to the shop I use. Last one got crank turned,bored,guides,and seats ground to match the new valves for around $250

No they aren't. They are really cheap!! Go price parts for a Mag or a KT engine! These Kohlers can be rebuilt for around $350 in parts and machine work unless you need odd parts, or ones not often replaced.


Not all automotive rebuild shops will touch a small engine. $250 is pretty high for what you had done. Between $50 and $100 high.... I'd shop around some more.

I think I pay about $175 for cylinder bore, crank polish, and valve seats re-cut. Add $100 for the rebuild kit, a few more dollars for replacement bolts, sealant, etc. Like Jon said, under $350.

149 camshaft
 

Thanks sawdustdad for the Napa number. Will give him a call.
Twoton, I am using the Kohler service manual but some times I over look things or just simply don't understand them. I wasn't sure about the governor so I left it in the block. If I can get the block, piston, and cranked checked I will remove the governor. I really appreciate every one's help. Have a great day.
Bob

Governor is easy to take out. Just remove it. Need to check it out anyway.

Oh good. I was just wondering. I bought the one from Maple Hunter as I like to have a hard copy. Gives me something to look at during my coffee break.:biggrin2:

I was wondering if you recall any oil leaks at the governor cross shaft/bushing and if you have removed those?:bigthink: Just curious,..I think some would replace those as a normal course of action...:bigthink:

You too Bob.:beerchug:

149 Engine rebuild
 

Strange things happen. A few weeks ago I called Givens machine shop in Charleston, Wv. Talked to a lady that answered the phone. Asked her if they could bore an old Kohler engine. She hollered to some one to see if they could. She said no. Thought I would try again today. Called and a man answered. Asked him the same question and he said they sure could. Bore it 10, 20 or 30 over. Said they would check the cyl, piston and crank to see what needed to be done. Going to try and take it to them tomorrow. I sure hope they can do the work.

Twoton, the service manual I have was downloaded from the tech. section and printed out. I am going to remove the governor today. Did not see any leakage from the shaft. Thanks and have another great day.
Bob

K321 rebuild
 

Took the engine block, crank shaft, piston and valves to machine shop yesterday. Hopefully they will get back to me Mon. or Tue. as to what needs to be done and the cost. Thanks for every one's help. I am sure I will need help as I put this engine back together. If any one knows of any thing that I should be aware of, please let me know. Have a great day.
Bob

I usually wait for the machine shop to tell me what they need to bore to before I buy the new piston and rings and rod.

Not too tough to put it back together just follow the manual very carefully. Shimming the camshaft and the bearing plate are the two things that require you to use trial and error, take your time and don't be afraid to take it apart and try again. If you don't have feeler gauges, you'll need a set.

Seating the crankshaft oil seals is another that you need to read the instructions carefully.

Be sure the oil hole in the connecting rod at the crankshaft bearing is facing the correct way (toward the camshaft IIRC). Make sure the oil dipper doesn't hit the oil pan. I've had to trim them before on a K241 with a flat oil pan.

All of this is explained in the manual. Take your time and it'll be a great learning experience.

Just a couple of things that come to mind;

Make sure that you have a clean work area and that you keep everything clean and organized. Is the machine shop going to clean the block for you? If not you will have to clean it yourself before you start. And, using a tap, clean out all the threaded holes in the block.

Use an engine stand if you can.

Get a gallon bucket and put a couple of quarts of 30 weight in it. Dip all your moving parts in it before assembly.

Did you get your replacement cam yet? Remember, you will have to set the camshaft end play;

http://www.onlycubcadets.net/forum/s...317#post388317

Take your time and be careful installing your new rings. You don’t want to deform or break them. You might find it helpful to use ring expanders;

https://www.amazon.com/dp/B0009OMYC4...V170RD6O&psc=0

Clean up your timing marks and highlight them with a white or yellow paint pen. And remember, you can set the timing using the static method while the engine is on the stand or workbench. You might find this easier than after it's installed in the tractor;

http://www.onlycubcadets.net/forum/s...080#post276080

If you have a dial indicator, it is a good way to set the piston at TDC when you adjust the valve - tappet cold clearance;

http://www.onlycubcadets.net/forum/s...227#post338227

While you’re waiting on the machine shop, you can plane the head;

http://www.mgonitzke.net/cubcadet/tools/headgasket.pdf

https://www.youtube.com/watch?v=L1jF...ature=youtu.be

And rebuild the carb';

http://www.mgonitzke.net/cubcadet/to...rb_rebuild.pdf

Get a couple of quarts of Brad Penn break in oil;

https://www.amazon.com/dp/B002RF8IN2...V170RD6O&psc=1

Follow Merks advise for breaking in your freshly rebuild motor;

http://www.onlycubcadets.net/forum/s...0&postcount=19

Don’t rush it. Anything worth doing is worth doing twice if that what it takes to get it right.:ThumbsUp:

I'm going to save this list of really good ideas for my turn at rebuilding one of these. Thanks for posting them.

Read this before you do.....


Machine shop better clean the block. They have to after boring it. Only a really bad shop wouldn't give you back a clean block. Most shops you have to tell them NOT to paint it too, or they will. That said, mine are usually pretty clean before I take it to them. They still will tank it after boring it.


You don't need an engine stand for a K series. I don't even use a stand and I have at least 3 engine stands. Set it on a bench. It's not a big motor.


Don't do that. Just use an oil can. Dipping parts in oil gets it everywhere. No reason to make such a mess.



That's in the service manual..... he better remember to do it. It's part of the steps of overhaul, just like setting the end play on the crank.


These piston rings are small. You don't need that tool. You can use your hand. But whatever.


NOTE: You must be referring to the marks on the flywheel. Be specific, there are two sets of timing marks on the K series. The set that are internal, and the set that are external. Doesn't hurt to mark both, but you are talking about the ones on the flywheel. Painting them white is definitely a good idea.


You do not need to do that. It's is ridiculously unnecessary. The cam closes both valves before the piston is very far off the bottom of the compression stroke, and opens them again when it almost reaches the bottom of the power stroke. If you can't find a spot with your eye in 300 deg of crank travel, you're blind. Only thing you have to watch on this engine is that the exhaust valve isn't sitting on the ACR. If you set valve lash while the cam cover is off, and you should, this is easy.

You don't need a dial indicator to set anything on the K series. You can even set crank end play with a feeler gauge. Book tells you how.


Yep.


You should always run the same oil the engine is going to use normally to break it in. People who invented "break in oil" are just making money selling to people who don't know. It's a gimmick.


Good advice here. :beerchug:



Sorry twoton. I like you man.... I really do. Just sometimes you go above and beyond, and it's too much. Not all the things you see other people do on this site are necessary, or good.



Here's my advice:
1.) READ the manual and FOLLOW it!
2.) Ask questions if you need help.

Good to see some of Matt's old links still work. There's some good info there on home plating.

149 rebuild
 

Thanks for all the good info. Every one has their way of doing things. If that way works for you then that is all that matters. Thank you twoton and Jmech.
I will refer to the service manual and I am sure I will be asking help for specific things.When I took the engine apart, the camshaft gear was only aligned about half way with the crank gear. I thought that was not correct but I do not know how to correct it if needed. The machine shop called this morning. The cylinder only needs honed. Piston checked ok. Connecting rod needs to be turned .010 under. They will tank the block before and after honing. They will grind the valves and seat, lap them in and install the springs. Going to get a new piston ,.010 over and rings. I will ask them to install rings and piston. I could probably do this but I feel they are more apt to do it correctly. I am making a small work bench with two saw horses and a plywood top. Will be taking it slow and keep things as clean as possible. Thanks for all your help and have a great day.
Bob

Bob I have a question. Did you give the machine shop the specs of the 321? Not to second guess them but there are specific go/no go measurements of taper, out of round, and thrust/face for it. They sound like they nailed it with the crank journal needing to go .010” under but that piston really looks like it got beat around for just a hone to work. Again, it’s only worth a couple questions to them, maybe they have a B.A. hone but to take out that much material to get it straight again I would think they’d have to bore “.020 or even .030” to get that out. If any other goo hoos more saavy want to chime in please do, just expressing my humble opinion.

Surprised they didn't want to bore the cylinder.

There is a type of hone that will get the cylinder true again, don't remember exactly what it is, but it serves the same purpose as boring, but only when a few thousandths are needed to be removed. JMech will know what I'm talking about. Or maybe Alvy called it a BA (bad ass?) hone. Not sure the correct name.

You might ask them how they are honing. Generally, that does not true the cylinder, just renews the cross hatch pattern. Unless they use the special hone that does true the cylinder.

Did they tell you to get the .010 over piston and rings? Or had you already purchased them? Did they decide to just hone because you gave them the piston and rings before they mic'd the cylinder? So are they just trying to accommodate your new piston rather than boring it .020 like it really should be? You should ask.

Not trying to nitpick, but these are a few questions you should ask to be sure you'll get a good result.

If they put a new piston in an egg-shaped cylinder because they didn't bore when they should have (perhaps because you gave them the piston and rings to use) then you'll have a short lived engine. Perhaps measured in dozens of hours rather than hundreds of hours.

Lots of us have been through these situations and learned from our mistakes, just trying to help you avoid some of these pitfalls.

Machine shops use rigid hones. I'm not going to say every shop.... but every shop uses a machine rigid hone. Put the block in, and it does the work for them. Don't have to manually run it up and down.

This one is pretty fancy. Some have ones this nice, others don't but they all work the same way.
https://www.youtube.com/watch?v=jx4tRAU_Tp8


Mike, I didn't think the piston looked that bad. I'm not surprised that a honing is all that it needed. If they caught the crank, I'm sure that they checked the cylinder. OP said he was going to get a .010" over piston, I'm taking that to mean he does not yet have one.

Good to hear of your progress Bob and will be looking forward to your updates!:beerchug:

:popcorn:

Kohler 321 rebuild
 

I took a copy of needed specs along with the block. I believe that it had all info needed. It did have the tolerances for sure. It was already a .010 over bore. The pictures I posted made the piston look a lot worse than it was. Machine shop said it was in tolerance, but I ordered a kit with .010 over piston and rod .010 under. The shop said the crank was out .002 This shop has been in business since 1955. They did a lot of work for friends that I was drag racing with in the early 60's thru late 70's. I am really nervous about doing this but with all the support I am getting, I believe I will get it done. Thanks to all that are pitching in and have a great day.
Bob

Sounds like it's working out fine. I'd encourage you to try to build the engine yourself. The Kohler manual is very good and as long as you follow the steps carefully, you should be OK. The first one is a little intimidating, but it's actually fun, and if you take your time, it'll come together and you'll have that satisfaction of having done it yourself. :beerchug:

149 rebuild
 

Received my Piston, rings, connecting rod, and gasket kit in the mail yesterday. Block is still at the machine shop. Shop probably works on larger more money making jobs first. Eager to get started but will have to wait. Cleaned the replacement cam that I bought from one of the members. Looks pretty decent. Going to make my small work bench Monday. Have a great day.
Bob

Better take them the parts.... they can't finish fitting without the piston and rings. Probably waiting on you....

Bob, sounds like you're getting close to build day.

Make sure and take some pics for us!

149 rebuild
 

Took my new piston & rod to machine shop this morning. Said they will have it ready tomorrow afternoon. Have a couple questions.
1. Can you use the old thrust washer on the gov. gear if you are using the old gear?
2. What holds the gov. gear on shaft? Looks like it would slide right off.
Starting to get excited and anxious and also nervous.Will post pictures as I go forward. Have a great day.
Bob

The looooong screw that goes in the block by the governor arm hold the gear in.

You can reuse all the shims in the engine, except the gasket shims on the rear (or front if you go by Kohler) bearing plate.

149 rebuild
 

Thanks J-Mech. I thought that was what that loooong screw was for, but it seems the gov. gear will slide about half way along the shaft. Is that normal? Have a great day.
Bob

Normal, yes.
When the engine is assembled and running, remember the governor cross shaft is in constant spring contact with the governor. It doesn't move. Only reason for the retainer screw is so the gear doesn't come off the shaft during 1.) Starting, and 2.) Engine removal.

149 rebuild
 

Thanks J-Mech. Will proceed to the cam install. Think I will build my work bench first.
Bob