Boring out a 14 hp kohler magnum

[Lymedog 2]

Hello all,

I'm posting a question regarding the boring out of a 14 hp kohler magnum to up the horsepower to 16.

My questions are as follows;

1 - can a bore out of .25 inches be possible

2 - would I need to change the crank shaft

3 - would the cylinder head cover needed to be replaced

4 - would it be less costly just to buy a 16 hp magnum instead

Just posting the questions...

If you can help or advise... Please comment... Thanks

[otrelwood 32]

1/4 in oversize is alot on an aircooled block could make it run hot ,the stroke is the same on the big kohlers so crank is ok,the head would need to be the same, as a 16 hp has one more bolt not interchangable 10 as opposed to 9 on the rest of the big blocks dont know about price difference 16 sare expensive but worth it  just saying

[MalMac 1,332]

I am sure others will chime in here that know more than I, but if memory serves well I don't believe you have enough to bore that much. I think the 16 is a whole different block.

[bitten 134]

You might want to go to Brian Millers Garden Tractor Pulling tips and tricks. A lot of good info there.

Good Luck.

[Forest Road 594]

Ill second Brian millers site. Lots of great info there. You can do quite a bit to your 14 to gain more power.

I have a k-341 I've been planning to build myself. Unfortunately life keeps getting in the way. Just take your time and so it right!

David Kirk has some great info as well. Check out his hopped up k-241

http://www.kirkengines.com/

[diesel cowboy 263]

I tried to do that once with mine and found out that there would only be around .025-.040 of an inch left for the cylinder wall.         Stewart

[Wheel-N-It 2,976]

Good idea but not the correct block. I would think for most working applications you should be able to get plenty of power with a good rebuild including a new cam, and a kohler 16hp carb.  What are you needing the extra hp for?

[Lymedog 2]

Thanks guys,

Thanks for the info... Wheel -n-it ... I thought I could get away with a bore out instead of getting a different engine. 16 kohler single bangers are hard to come by. I was gonna try maybe some pulling too. Stock class... Don't have the time right now to do a full upgrade. I have been on millers site too.... The upgrades can get really costly. I'd rather have a stock single banger kohler than a blown out 14 that would need an overhaul every 15-20 pulls as miller says in his site. Major upgrades also make the tractors lose their use as a standard garden tractor.

The guy who we bought it off of was gonna give the 314-8 to his son as a puller. I would love to someday upgrade to a Vanguard 23 hp twin... Which has the balls to pull and is very efficient with fuel consumption. Just 1600 clams is not readily available.

[Lymedog 2]

I also read that the 16 hp kohler magnum might have more torque than a twin 16 Onan.

[Wheel-N-It 2,976]

OK, I understand now. Not trying to discourage you from pulling but I hear (from the pullers themselves) even the stock class can be quite expensive.

If you need an engine, you can always use the K series of Kohler. They are contact points and condenser ignition unlike the magnum. You will just have to rewire the harness for them accordenly, including a new key switch. I did this conversion to a 310-8 this year. I replaced the 10M Kohler with a 12hp K301.

BTW, I have a 14M in a 414-8 and love how smooth the engine is. Its smooth like a 12M. The 16hp Kohlers are not as smooth, but I love them too. I find myself more and more jumping on the 416-8 when I have some mowing to do.

So many Wheel Horses, So little time..............................................................................

[Lymedog 2]

Wheel-n-it,

I heard to many nightmare stories about the k series. Don't get me wrong, it's a cool looking and sounding engine. But, the magnum seies I think are more sound , less work (points..etc) and I have a few in my tractors now. I'd love a m16 to throw in the 14's place and use the 14m in a Penn. Panzer my older neighbor needs an engine for.

And no, I'm not switching to the blue side, I'm still a red horse at heart! I'd just like to add that panzer to my herd as a show piece.

I do own a kubota, but I don't bleed orange , just red!

[Wheel-N-It 2,976]

Lymedog,

Don't pay attention to the horror stories you have been hearing. Those old K engines are tough as nails. The M engine is basically the same as a K, just uses a magneto instead of points and condenser. Contact points are fine for these old flatheads. They don't turn up enough rpms to need more than that in my opinion. So if you can find a well maintained good running 16hp K then jump on it!

[boovuc 1,090]

The overwhelming majority of folks here will say the Kohler K series was the best small engines ever made. The magnum is a K series with a breakerless ignition.

You won't find any difference between a K and a magnum 16 HP as long as both had some maintenance applied during their lifespans.

[Lymedog 2]

Wheel-n-it,

I also read and heard that at higher revolutions the k can become a grenade in a can, with the balance gear breaking apart due to a brittle casting not a forging. I really didn't want to deal with the wear factors such as points and condensers. I rather have the breaker less ignition too. Especially if I'd wanted to pull on the competition level.

Like I have said in past posts, my dad and I owned a 310-8 magnum. We pulled everything from trees, rocks, dirt, lumber and deer with it. The motor has been through hours and hours of high grass mowing and still starts up every time,without a hitch. It's a true testiment of the durability and toughness of the magnum engine.

[baerpath 517]

Gonna add here about the higher rev's on a K series. Unless you go to a steel flywheel don't overspeed a engine for pulling. The balance gears are easy to get rid of.   The points on a puller usually get changed out to Chevy ones, I would rather have points on a puller for serious pulling.  Even on my twin we run a adjustable steel flywheel so wr can change the timing

[Lymedog 2]

Baerpath,

Why points?... Why would you want the extra hassle . Wouldn't the magnum be an easier engine to work on. They have the same power ranges with torque and hp. Didn't kohler drop those parts and o with the breaker less ignition?

How is the newer kohler command single banger? How does it compare to the K and M series?

[baerpath 517]

I don't have anything against magnums in stock form, My command doesn't have points but like I said we put a adjustable flywheel on if so we could change timing.  For pulling I would rather have the hassle and a better "Hotter" spark

[Wheel-N-It 2,976]

Lymedog, you can easily go 10 years before you have to change the points and condenser on a K engine. If you are inside the motor for anything its best to go ahead and remove the balance gears. I've got a K341 at the rebuilders now because tha balance gears broke. That happened with the previous owner, not me. Dont pass up a K341 just because it has points.

[Kelly 1,033]

Swap the bearing plate and a few other small items and put the magneto system on a K series, it's a bolt on, The rest of the engine is the same, balance gears if it has them come right out. 

[Lymedog 2]

Never worked on a K.... Seen em , drove em but never worked on one. How do I take out the balance gears and I never swaped points for a magneto system. I've worked on magnums and command pro's.

I lost the last two motors I looked at. I even HAD a shot at a Kohler Com Pro 25 hp horizontal but it sold so fast. I could of swaped it for my kubota CH 20 and threw the 20 in my 416-8. It would of been awesome but just my luck.

I have seen a rebuilt 341 k on Craigslist , but the guy wants $500. Still searching, but now I won't pass on a K 16 hp either.

Thanks guys for the insight... Let me know more about the swap out of the points and the removal of the balance gears.