129 CC Hydro rattling and knocking
 

Hi guys, Got a problem. Rebuilt k301 12 hp in a 129 CC that starts to rattle and knock after it gets warm while under load plowing snow. Governor will load up carb then engine will die. After 15 seconds, start it and it throttle's up and will run fine w/no rattling or knocking. It sounds to me like it goes into an advanced ignition state but the timing is set correctly. Will do this some days and not others.:bigthink::bash2: Throttle up real fast to clear any carbon buildup seems to help but not always.:bigthink:. Anybody out there ever have this happen to them and do you know of a remedy. Could the hydro pump be dragging it down or is it in the ignition? If anybody knows what's going on let me know. Driving me crazy! Bob O. out

Sounds like a fuel problem to me. Float sticking most likely. Pull the carb, clean it and put a kit in.

No, the hydro pump isn't the issue. Rattling and knocking could be the PTO though.

129 CC hydro
 

The pto does rattle but this knocking comes and goes. It could be the carb but has new float and throttle shaft w/foam seal on shaft as per Brian Miller of A-1 Miller's repair. Could the pin that activates the points be hanging up?

No, the points pin doesn’t give issues. I guess I shouldn't say it *can't* be, but it's not likely.

Did you overhaul the engine yourself?

I recommend avoiding Brian Miller's site. He is of very questionable chatacter.

129 CC hydro rattling
 

Yep, overhauled myself. Went thru all of it and even removed the grenade gears. There was substantial wear on the shafts and too much slop. Why do you question Brian Miller? Have you heard bad things about him and if so do you recommend someone else?

Yeah.... there are bad things about BM. Check out his arrest records, and time served. Nuff said. I recommend Don Vogt, Dale Merkel and myself on this site if you need info.

Did you bore it? Grind the crankshaft? New rod, piston, rings ect? Did you check piston skirt clearance and ring end gap before assembling?

129 CC hydro rattle
 

Bored .020 over, rod journal .010 under new piston rings end gap and cyl skirt all checked. all within specs. It's using oil like crazy now and can't figure out why. Maybe I used it to hard when pushing snow. Don't know how much the K301 can take but I work hard sometimes.

I don't think you can "work it too hard" no matter what you do, other than running it out of oil, running it too lean or letting it overheat due to a mouse nest inside the tins. These engines are basically bullet proof.

J-Mech's probably nailed it on the fuel issue. Next time it tries to die, pull the choke and see if that helps momentarily. If it does, they you've likely confirmed a fuel supply issue. Running lean can cause a knocking sound if I'm not mistaken.

129 CC rattling
 

Thanks, will check out the fuel filter and the carb. As I think about it you guys could be right.

Did you shim the cam end play to spec?

What oil are you running in it?:bigthink:

Is the oil drain back hole towards the bottom like in this picture?
http://www.onlycubcadets.net/forum/a...1&d=1518183795

I would double check to make sure the breather assembly is installed correctly. Next step I would do is remove the head to make sure there is no gouges-marks in the cylinder.

If an engine is using huge amounts of oil, and recently rebuilt, something went amiss in the process.
It is normal to use a little oil till the rings seal, but not huge amounts.
Did you bore it or have it done?
Is this your first attempt or are you experienced at engine rebuilding?
Did you put the piston rings in the bore individually, and check the end clearance before installing them on the piston, and assembling?
Was the bore washed thoroughly with hot soapy water before any assy. was done?
It sounds like it got hot during break-in and you sized the piston, causing ring/piston/cyl. damage.
But we need a lot more info before advising investigative tare down,
as this may well not be the case.:bigthink:

129 CC rattling
 

What would that cause if not shimmed correctly?

129 CC rattling
 

Had it bored out by a reputable shop in Billings, Mt. He fit the piston to the bore and end ring gap was checked, with in specs. The cylinder was washed out with brake clean and dried and coated with oil. Piston cleaned the same and coated with oil. All parts on assembly were cleaned and assembled the same. Rod journal had a light coat of lithium grease applied at assembly. Head was lapped on glass plate till flat. Valves were ground as well as seats. Valves lapped by me and my brother. Brother is Detroit Mech w/over 30 years experience. New crank bearing on pto end. New valve springs. Cam reinstalled with all shims. Something has gone wrong with the piston and rings because it is using more oil than it should. If carb was set too rich it could wash out the oil in the rings causing failure of the oil rings, I guess. Have built engines in the past and have never had this trouble. Getting older and maybe I'm losing it!:bigthink:

Mobil one synthetic

Just like the picture shows.

129 CC rattling
 

What is the best procedure for break in?

That is your Number 1 problem with oil usage. The engine needs to broke in using dino oil. Synthetic is ok to use after 10 to 15 hours run time. I would stick with good old dino oil. if it was my Kohler.

I use Kohler engine oil. I use straight 30 weight above 32 degrees and 10W-30 below 32 degrees.


This is how I break in a new engine.
Vary the RPM from idle to wide open for 45 minutes.
Change oil.
Drive your Cub Cadet around for the next 45 to 60 minutes. Vary the RPMs as you drive it. I like to pull a light load like a half loaded trailer or aerator.
Change oil again.
Put a heavier load on it. Vary the RPMs.
After 2-3 hours of run time I find a event like a plow day or something I can put a heavy load on it and drive it like stole it.

This is how I break in any Kohler engine I rebuild. Anyone that I rebuild an engine for gets told the same thing. I haven't had one let go.

When rebuilding chevy engines, that's what I learned from old Smokey! I followed Brian Miller's advice on this break in and used 30 wt dino oil for the first oil change than switched to synthetic. That, could have been the problem. He said to run it at almost wide open for an hour and I think that was too much heat on the rings. Looks like another rebuild is in the maken's. Damn.

Try dino oil. You won't be out much except the price of oil. Next step I would do is pull the head and see what the cylinder wall looks like.

Synthetic oil is to slick for the rings to seat right in the bore, if they ever do seat. Good old dino oil is the best. Best to stay from Mr. Brian Miller. :American Flag 1:

Best to stay away from synthetic oil in these old air-cooled, non-pressure lubed engines. I tried some Royal Purple in mine and it burned a lot. Switched back to regular SAE 30 Pennzoil and I didn’t have to add any all season. These engines aren’t what synthetic oil was designed for.

I'm working on a seminar that I'm doing on rebuilding a Kohler engine. The seminar is in Branson, Missouri this March. Possible problem areas come up as I work on this seminar.


Check the drain back hole in the block(breather area) to make sure it's not block. It is possible there is a ring either broke or installed wrong.

Not to sure these gravity flow fuel systems flow enough with a filter if it is a paper element, a screen type filter should already be on the shut off valve in the tank ? Just a thought, but you may have other issues at this stage of the game .:beerchug:

Good luck with your troubleshooting, now my real question, I have read Miller's pulling site but Don't know anything him, seriously just asking.
Apparently more is going on but I enjoyed reading long winded explanations on the Kohlers.
Thanks for this site, I truly enjoy it.:beer2:.
Kevin

129 CC hydro rattling and knocking
 

I want to thank all who replied to my problem. This truly a good forum for us Cub Cadet owners. I also want to thank Only Cub Cadets Forum for being there and providing us a place to look for help and to share ideas. Thank you all who replied. My faith in mankind has been restored, but only when it comes to tractors and farm equipment. I am retired and used to be the best baler and swather mechanic in Billings,Mt:biggrin2:! Just kidding! But I was good. Time takes it's toll on all of us and after awhile it's great to find help when you need it and to help others when you can. Thank you all!:American Flag 1:

I'm 10 years out from retirement and would like to overhaul my Kohler 241 by that time.
I'm interested as I like slower high torque motors, example ISX at work, 115 2 stroke Mercury.
I had a Farmall A that we honed the cylinders and placed fresh rings and again, it was just a toy and ran fine.
My Cub will serve as the same thing, only smaller.
I hope It's something simple for your Kohler, good luck.

Kevin

I had a 115 2 stroke merc. !967 6 cyl with 3 carbs. One of the first with electronic ignition. Was a real runner with a great sound. Mike:beerchug:

Cool! My 115 is a 4 cylinder, 4 carbs, it is strong, when running, powers a heavy center console deep V.
Meanwhile, back to topic.
Keep us updated.

Kevin