Kohler engine rebuild progress and questions

Wow, I guess you don’t understand what I’m asking or your schooling has left you lacking. An 1/8” less than a 1/4” is an 1/8” inch. Don’t they teach fractions anymore? A 1/4 can be stated as 2/8, that’s how you subtract fractions make their bottom numbers the same size, but the multiplier of the bottom denominator has to be applied to the numerator(top number) as well. However, I really think your try to say is the rings come within a 3/8” of the top of the cylinder wall and your bad spot only goes down a 1/4” from the top of the cylinder wall. This means the rings won’t get into the bad spot. If you are fudging these measurements you are only hurting yourself.
 
In addition to the plastic governor gear I highly recommend replacing the cross shaft that the gear contacts. If the rivet holding the tab to the shaft breaks you'll be doing it all over again......
 
Wow, I guess you don’t understand what I’m asking or your schooling has left you lacking. An 1/8” less than a 1/4” is an 1/8” inch. Don’t they teach fractions anymore? A 1/4 can be stated as 2/8, that’s how you subtract fractions make their bottom numbers the same size, but the multiplier of the bottom denominator has to be applied to the numerator(top number) as well. However, I really think your try to say is the rings come within a 3/8” of the top of the cylinder wall and your bad spot only goes down a 1/4” from the top of the cylinder wall. This means the rings won’t get into the bad spot. If you are fudging these measurements you are only hurting yourself.
They do still teach fractions in school. I don’t know what my problem was this morning, but we were in a hurry to leave… I’ll re-check, but from what I saw it looked like it would need to be bored…
 
I’ve been rebuilding my Kohler K161 7hp motor for my IH Cub Cadet 70. I’ve got it disassembled and painted. This is my first motor rebuild and my dad has only ever did one before many years ago. I have the ultimate standard sized rebuild kit from isavetractors. Some folks say I need should bore this and my dad thinks it’s fine and others say it’s 50/50. Do you guys think I need this bored? Did we do a bad job honing? My dad thinks the low spot is high enough that the piston won’t reach it, is that true? Any thoughts/help are greatly appreciated.
Picture is a little dark to the right … is that actually missing metal or simply a rust stain? Stains don’t cause any trouble at all and will still be there after hundreds of hours. Before worrying about it, make sure the top ring is actually going to come up that far.
The honing you have so far looks fine, I’d stop there. Don’t make the cylinder any bigger than you have to.
 
Fritz, without seeing it in person not for sure but I think he has lost metal to about 010” at least. He “liked” your post but per reply 6 he claimed he is taking it to a shop for them to evaluate it. Pretty sure they will tell him it needs bored out. If he don’t he better have Grandpa Love send him a little magic.
 
I just called a nearish by shop and they estimate $65 they’d charge me only. I’ll take the motor along next time I go to their area. Many forum members were not impressed with our cross hatching job... Do shops do a good job cross hatching or is what like I tried good enough?
 
Actually in my opinion the fact that you didn’t have a cross hatch pattern that met someone’s standards on here would not have made or broke the success of your ring job even if your cylinder bore would have been in acceptable condition. Back in the early days many engine were re-rung with very little hone cross hatch. I probably should have found a better article that explains the finer points of a good crosshatch pattern, but the linked article had a good example photo. Good honing finish It mostly about the microscopic grooves acting more like a file as the ring passes them if the fine hone lines are not angled from the rings. The near 45 degrees crosshatch lets the rings pass exposing them to a less aggressive surface. This is similar to crossing a speed bump at an angle instead of straight on. Secondly, the angle is better for holding the thin layer of oil in place to for ring and piston lubrication. There are other benefits but these are the main two. Don’t get me wrong when I hone a cylinder it is crosshatched. If the shop you take it to does quality work it will have a good crosshatch finish.
 
Goto page 105 and read what Kohler recommends on honing. It will help you immensely.
Also i recommend have the machine shop check you crankshaft and flywheel for fracturing ( cracks)
Be a terrible shame for you to do all work and have issues .
I recommend your measure everything ,if not your guessing, guessing cost three times what looked at in approved inspection .
here’s the manual for you ( link)
 
Does that engine have balance gears?? If so the needle bearings and shafts are usually shot. If you have a machine shop that knows what their doing you can have them re-balance the crank and leave the gears out.
 
It’s best to have the piston there at the same time if you’re reboring that cylinder or installing a sleeve so the piston can be honed to fit. And it should be a new piston. And I am not sure what this 65.00 is all about. That’s about 1/2 hr. Of labour and to bore and hone and fit a piston takes more than 1/2 an hr.
 
Does that engine have balance gears?? If so the needle bearings and shafts are usually shot. If you have a machine shop that knows what their doing you can have them re-balance the crank and leave the gears out.
I very well could be wrong, but I don't think the little K161's ever had balance gears.

An alternative to $$$ boring would be to check out ebay for a decent block with a nice bore at a reasonable price.
 
There might be some “nice” people around that don’t mind giving a young man a break who is learning to rebuild an engine. ;)
Well that’s the way I do things. More interested in see them go away happy. Give them a break. But if it’s not a private shop I don’t think will happen. Plus as I asked , what does this 65.00 cover. ? Would be nice to know.
 

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