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644 more pics

Posted: Sat Sep 23, 2023 9:48 am
by Harry
Still moving dirt that I dug up a couple of months ago. I would back drag to loosen the dirt from the pile, then scoop it up and move to fill in low spots. The Kohler seem to struggle when using the loader. The backhoe never seems to tax the engine at all. The weather seems to be holding and no rain in the forecast this week. Hopefully get to move more through out the week. :peace: Harry

Re: 644 more pics

Posted: Sat Sep 23, 2023 10:28 am
by Eugen
That looks like fun @Harry . Second picture is such a classic look, tractor at work. :thumbsup:

Interesting about the kohler on loader duty. I too have heard the engine slowing down a little and the governor kicking in when pushing the loader in sometimes. I don't remember very well but I think traction is what I lose first. I'm just not sure a stronger engine would enable me to do things with my 644 that I cannot do with the kohler. 🤷‍♂️

Re: 644 more pics

Posted: Sun Sep 24, 2023 9:17 am
by thebuildist
I don't have a ton of experience in this kind of question. But I can compare my old '73 Kohler single cylinder 12 horsepower 442 to my much newer Onan/Linamar twin cylinder 20 horsepower 4020.

And it is surprising how little difference there is between the power of the two machines. The twin 20 horsepower definitely has more steady available power to the belt PTO.

But as far as driving and pulling, it's hard to tell the difference.

I think that's for a couple reasons: number one the Kohler outperforms its class when it comes to bearing down and grunting through. There's just something about them that they just really knuckle down under the load and grunt and stubbornly maintain RPM more than you'd expect. I think maybe because they have an extra large flywheel, and all that rotational inertia helps it?

The other thing is that with the size of the hydraulic pump and motor, you can only realistically transfer 12 or at the very most 14 horsepower from the engine to the wheels, no matter what engine is in there. So again you may have power to spare to run a big PTO implement while driving, but the actual act of driving is not substantially stronger with a larger engine.

Just my $.02.

Bob

Re: 644 more pics

Posted: Sun Sep 24, 2023 9:42 am
by Eugen
@thebuildist it's no secret I like the Kohlers. I do wonder sometimes what it'd be like to put a torquey diesel in my 644. :25:

Re: 644 more pics

Posted: Sun Sep 24, 2023 10:24 am
by MattA
I think the loaders and backhoes had larger hydraulic pumps and possibly higher relief pressures. Its certainly possible that Harry's 14hp Kohler is in good working order but is simply getting overwhelmed. @sdunt would know better. I recall reading somewhere that the 10hp and 12hp tractors may loose rpms before the hydraulic relief opens.

Re: 644 more pics

Posted: Sun Sep 24, 2023 11:15 am
by Harry
My reliefs never squeal when under an extreme load. The engine bogs down and it makes what sounds like a clanking noise. If I push it to hard the engine stalls. To adjust the reliefs you have to remove the hoe to get to the hole. I’ve read the procedure in the manual and I’ll just say it’s not easy to even remove the cap on the tcv. I don’t believe my problem is in the relief settings. I think I’m expecting to much from the small GT. I’m sure a bigger GT would get the job done easy, but that is not going to happen! :wife: :rofl: :peace: Harry

Re: 644 more pics

Posted: Sun Sep 24, 2023 1:16 pm
by Eugen
MattA wrote: Sun Sep 24, 2023 10:24 am I think the loaders and backhoes had larger hydraulic pumps and possibly higher relief pressures. Its certainly possible that Harry's 14hp Kohler is in good working order but is simply getting overwhelmed. @sdunt would know better. I recall reading somewhere that the 10hp and 12hp tractors may loose rpms before the hydraulic relief opens.
I don't know about the lbh but I do know the 644 loader I got has the same size pump as the 444 and the 244. Although, I'm inclined to think that a bigger pump just had higher volume but will generate the same working pressure.

@Harry , I'll try my 644 harder next time and will report. My memory is the the loader does make the valve squeal at times.

Re: 644 more pics

Posted: Sun Sep 24, 2023 1:33 pm
by thebuildist
It is true that the loaders have a higher relief setting than the GTs. The GTs are something like 475. While the loaders have something like 1200.

But based on the mechanics of the travel motor, it will expend a full 12 horsepower worth of work before that relief valve ever trips at 475.

Bob

Re: 644 more pics

Posted: Sun Sep 24, 2023 8:31 pm
by MattA
Found this on google
A7819D9A-795E-48BB-B686-8CD0EB148978.png

Re: 644 more pics

Posted: Sun Sep 24, 2023 9:06 pm
by Eugen
Interesting again @MattA !