Noob to Kohler Rebuild

Hand_108 · #1 12-01-2013, 05:22 PM

Hey all. Picked up a QL 1450 with "no compression". Well I cleaned out my garage and organized some things today and decided to pull the motor and have me a little look see.

Confirmed the worst with a broken connecting rod. It was in many many pieces in the bottom of the motor. I have now stripped the motor minus the fly wheel, crank, cam and valves. Going to pull the fly wheel later as I have to borrow a puller. Looking at the cylinder wall it looks, to me, ok. Piston "looks" ok but I plan on replacing both with new Kohler parts.

My biggest question is this, anyone please let me know if I am dumb thinking this.

I want to have machine shop bore it to the max and then put a new cast iron sleeve in it to bring it back to stock. Is this common or even possible? My thought process with this is, I don't really want to over bore, over piston, over ring it. I hope I am explaining myself correctly.

I have done minor over hauls on Briggs in the past but I want this machine to last another 30-40 years. Nothing special. Not a hopped up motor or anything. I do plan on "repainting" everything and refreshing the externals along with the internals. It is torn apart so might as well replace as much as I can with new.

Next question is, where is a good place to get a master rebuild kit? Gaskets, seals, bearings mainly.

Is there valve guides or valve seats in these motors that should be replaced? I also plan on grinding the valves and if there are valve seats that can be replaced I will do that at that time also.

Want to make sure all I get/have all my bases covered when I take it to the machine shop and start throwing $$$ around.

Please let me know if there is something else I should look into/at while I have it out and sitting on the work bench.

Thank you all for your time.

John

J-Mech · #2 12-01-2013, 05:47 PM

Yes sleeving the motor is possible. Doing it just to do it is not common. There is no reason to sleeve this motor. It lasted 30-40 years with the original bore, it will do the same if it is bored .010, .020, .030 or whatever it needs. I have no idea why you wouldn't want an over-sized bore. It really doesn't change anything. Plus the cost....

Yes, there are replaceable valve guides in this motor. No seals. The seats have to be cut out, and new ones installed.

You can buy direct from cub cadet or kohler for a kit. Here is a link to an E-Bay store that I plan on getting my next kits off of. Just found them this year and plan to use them exclusively if their kit is as good as it looks. I'll be ordering one this week. Stens also offers a kit.

dvogtvpe · #3 12-01-2013, 05:49 PM

putting a sleeve in is pretty expensive vs. just boring it .010 os . We would only do it after it was bored to .030 and needed to go larger.

It's getting to the point I don't even check out of round or taper anymore. if the bore shows any amount of wear I just bore it to the next oversize. the extra life you get out of an overhaul with a clean fresh bore seams to more than outweigh the money saved by not doing it.

Sam Mac · #4 12-01-2013, 06:23 PM

Quote:

Originally Posted by dvogtvpe

putting a sleeve in is pretty expensive vs. just boring it .010 os . We would only do it after it was bored to .030 and needed to go larger.

It's getting to the point I don't even check out of round or taper anymore. if the bore shows any amount of wear I just bore it to the next oversize. the extra life you get out of an overhaul with a clean fresh bore seams to more than outweigh the money saved by not doing it.

Bingo!

Hand_108 · #5 12-01-2013, 08:47 PM

Thanks for the info on sleeving it. I will stay away from that for now. Thank you.

Would replacing the valve guides and seat be worth the extra work and $$$ involved?

How do I decided on which piston i need? +.010, 20, 30. I assume it is already stock bore but you never know.

New valves good idea or reuse old? They are burnt, like normal, on top. Or I should say black, but look good. No more abnormal than any of my other Cubs I have taken the heads off of.

I just want a solid engine that is going to last as long as it did before con rod broke on a PO.

Thanks all. Im sure I will ask another pile of questions as I go on.

Thanks again.

John

Sugarmaker · #6 12-02-2013, 06:01 PM

John,
If your planning to have it bored. I would have your machine shop check out the block and bore and advise you of the current sizes and if the bore crank and valves need work.
I took a block (14hp) to machne shop with the thought that I needed new valve guides, he looked at it and said it was a waste of money and time to change them. I followed his advise.
If you have a good set of mic external and bore mics you can do the measurements yourself.
Normally you only re-bore the cylinder wall to clean up to the next larger size. That way it could be rebuilt again someday.
If the cylinder needs bored, determine the current cylinder bore size, then buy the new larger piston and give it to the shop doing the boring work.
Hope that helps.
Regards,
Chris