Advice needed on a cub 123 hydro to 3 spd conversion

[rogergendron1]

hi everyone, recently my father passed away. he was an amazing mechanic, engineer, machineist, and gunsmith, but most of he was the greatest man i ever knew.
now my father belonged to a tractor club and did tractor pulling on the weekends at the fairgrounds up here in new Hampshire and vermont. he owned 5 cubs and a whole shop full of parts and specialty tools .

he built a cub 128 with a k341 motor for pulling and man that tractor is the most impresive machine i ever seen in my life.... no attachments just a big old puller with a hitch for the sled i think the only stock part left in and or on it was the block LOL!!!! he won many trophies with that puller. Therewas also a cub 129...believe not too shure of the model but it had a k341 motor and a hydro drive this had all the attachments i think cub ever made with it and a stock motor. there was another hydro cub not to shure of the model but this was a hydro drive also , it had a lift and a large custom made bucket loader he built from plans he got from a tractor club member! this was the most fun to play around on in the winter pushing snow around.
then there are 3 other tractors a cub cadet 123 in good running condition, a cub cadet 128 copleate rolling chassy with sheet metal in ok condion (need motor and wire harness) and ... an un-known model # narrow frame rolling chassy with 3 speed trans and INTERNAL break

there are also many many spare engine and tractor parts from various models.

[ol'George]

Welcome to occ!!
Didn't get your question, and some pictures would be most helpful!!

[rogergendron1]

now i inheareted the good running 123 hydro, all the other compeat and running tractor had to be sold to pay for funeral expences.

so i have a cub cadet 123 and and 2 rolling chassys, a 128 wide frame 3 speed, and a unknown model narrow frame with a 3 speed and the same front axle as the cub 123, and a but load of spare parts and a clean kohler K241 motor.

so my question is.... can i convert the cub 123 hydro into a 3 speed manual with internal break ?

or should i start on a whole new wide frame 128 ?

should i use the good running k241 to build a 27cid stroker for a puller or should i resleeve the 12 and go with that ?

what will i need to do this ?

i have a spare drive shaft set up from a 128 3 speed, the 3 speed transaxle with internal break and narrow frame, and a good running 10 hp k241 motor. the 123 has a badly worn k301 with a massive gouge in the cylinder bore but amazingly still starts and runs ok but has lost a lot of power.

me and my dad wanted to build a new puller together but unfortunatly he passed away before we could start.
i am new to cub cadets but by no means new to engine building and mechanics i am a machineist here in massachusetts.
i would like to get this started and any advice would help thank you

[Yosemite Sam]

Welcome to OCC.

Sorry to hear about your Fathers passing.

Many of the guys here can help you identify his tractors, related parts and specialty tools from pictures.

I personally wouldn't change the 123 to gear drive. Putting a 128 together... That I would do.

[twoton]

Hey rogergendron1, Welcome to OCC. I've heard it said that the 123 is the best hydro IH Cub Cadet built. Not sure about that but I think I would leave that one as is and built the other. Whatever you choose, hope you have fun. Sorry about your Dad.

[Cub Cadet 123]

rogergendron1. I'm sorry to hear about the passing of your father. May peace, healing, and happy memories of him be with you and your family.

The others are correct. The 123 is a solid well built, tractor and the very first of the hydros. There are plenty of gear drives out there that would make great pullers for you, but don't expect something to be anything different than what it is (IMO). A duck does not pretend to be a cow, nor does an ostrich pretend to be a wolf. A 123 was not intended to be a gear drive and I do not think that your time and $$ would be worthwhile to convert it into a gear drive.

We would like to see pics of your cub when you get a chance!!

Cub Cadet 123

[jaynjeep]

I am sorry to hear of your fathers passing... My father started me into cub cadets in the early 70's with a 100. He taught me that they were fun to play and work..and also a very useful tool to work with.

I agree with the others.... leave the 123 a hydro... maybe fix the engine, Build the 128 into your puller and have fun with it..

But they are your machines, so do what makes you happy!!

[rogergendron1]

ok so the 123 is a verry solid hydro!!!
than i guess i will leave it be and just do a rebuild on the k241 motor with some good porting for general yard work, a 3 angle valve job, mod the eyebrows for combustion chamber flow, shave the head down 50 thou, polish the combustion chamber and piston face, a reground cam for more torque from 0 to 4,000 rpms for general yard work and towing/pulling, a crank trigger ignition and a high performance coil. since i have a 301 crank and rod i can send out the 301 crank, rod and 241 piston to brian miller or lacota or really any good shop to be fully balance as a compleate assembly then do away with the balance gear setup if applicable. and a modded flywheel with the fins shaved down and balanced also

this will give me a fully build 27 cid motor designed for heavy dutie yard work and pulling/towing that should have ample power and last years, this with a 30mm oem kohler carb rebuilt for this pourpose and a free flowing exhaust fit for the motor should be all i need for general yard work for years and still be easy enough to use for my MOM to still be able to start it and mow with it !

i may also tune the hydro drive with new springs in the valves, and a clean up and simple rebuild with new fluid.

NOW for the pulling tractor ... the k301 that is coming out of the cub 123 when the k241 is ready for transplant has a seriously worn bore ! its 20 thou over as marked on the piston and is very loose in the bore and piston slap can be heard when running. i know going .030 over will NOT be enough to clean up the bore so ...

are there .040 over pistons available ? or is it worth resleeving ? or should i just go with a new block to be more cost efective ?

if i go with a new block i just may as well build a k341 16hp, after all this will be a strictly puller and i have spare 16hp pistons rods and a crank that needs a light regrind on the journal, but for pulling i am not shure if i should go with points ignition or solid state like a magnum 16 has, or mabe a crank trigger and coil, i am not shure on the best setup for pulling ignition wise, my dad said to me that the points and coil make a way hotter spark but rely on the camshaft and a rod and points on a spring... all of wich have play betwwen them that can through off the timming at high rpms but a magneto style with coil on the case cover and magnet in flywheel, even though it is stand allone and trouble free, makes a weeker spark because of the small coil, and timming canot be adjusted easily due to the fact that its controlled by the keyway on the flywheel...
this leads me to believe that the best pulling only style ingnition would be a crank trigger to high end hot coil with a starter generator that is setup on a sring so it can be disconected from the motor for a pull but sprung back in place for general driving around to keep a charge.

[rogergendron1]

i am keeping the hydro after i swap the 241 into it and repaint the frame...

i agree i like the looks of the 128 but the disk breaks are un usably warpped

the un known model i have has a narrow frame bolted to an internal break 3 speed axle in very good condition

is the external break better than the internal ?

and wich is better the wide or narrow frame ?

when i get back up to my moms house i will take a whole bunch of pics and mabey start a new thread in the build section or modified tractor section , right now the only pics i have are of thr 123 and they are o my phone

[Cub Cadet 123]

I am not a puller and I know very little, if anything about pulling tractors. That said, all of the pullers I come in contact with like the internal brakes rather than the external ones because of drag.....that is what they tell me. To answer your other question, they also prefer the wide frames over the narrow frames because of the spread of the frame and the ease of installing a larger engine.

Cub Cadet 123