JD744 w/noisy Yanmar 24hp Diesel

AKfish · May 5, 2010

Many of the Yanmar diesel's are direct-injected. They start better in colder weather and are a bit more stingy on fuel (efficient).

But, they're noisier than the Kubota; indirect-injected engines. (And Kubota will/does tout that fact!)

AKfish

Car Doc · May 5, 2010

Try power service gray bottle @ 200% it made my wife notice my Yanmar quieted down cant hurt.

Steve

ccsial · May 5, 2010

Noise is a pretty subjective issue. I think my X748 is fairly quiet. The loudest thing I hear is the fan at full throttle.

Only way to know for sure is to drive another one.

pilot-werx · May 5, 2010

I can say my 455 22hp diesel is not as noisy as the 445.

jcmseven · May 6, 2010

Joes427V,

I am with you. I knew you were adding the humor component, but I felt it a time to note that I have not been enamored about the ZTR performance on rough terrain. They are sweet otherwise and I would like to have both--in fact if I could afford it I would like to have one of everything JD sells, and two of some things.

To our OP,

I think the Power Service fuel treatment is a great idea. I run this in my diesels and have subjectively thought they run smoother with it in the tank. They also seem to get a bit better economy with it in there. Get the grey in the summertime. As for the engine, it is an indirect injected diesel which does make it a bit more noisy than the direct injected ones. When I owned my 595 (precursor to the 748) the loudest thing on the machine was the MOWER. I had the 62x, and it howled like a pack dog. Apparently, JD received some complaints about this as they revamped the design as a running change and made it some more quiet.

John M

normde2001 · May 6, 2010

"Comfort

<LI type=square>Power steering <LI type=square>Patented, ergonomic Twin Touch two-pedal foot control <LI type=square>Optional cruise control <LI type=square>Engine isolators reduce noise and vibration
High-backed contoured seat is suspended for added operator comfort"

Engine isolators are offered as a feature on the 2305 but not on the X744. You would have to listen to another X744 for a true comparison. The dealer is probably right.

Gary Clark · May 7, 2010

Thanks for the tip on the power service fuel additive, I'll try it. In the mean time, driving another x700 w/yanmar to compare is a clearly the objective measure of whether there's any problem. And thanks for the tip on the 2305 engine isolators, which is the only other yanmar I've listened to & compared with, which did have less mechanical rap.

jenkinsph · May 7, 2010

Gary,
As long as the dealer has checked it out and feels it is okay I would give this new motor some time to run in. I agree with the use of the additives mentioned too. This motor may quiet down a little with time.

It is brand new right?

Gary Clark · May 7, 2010

Brand new. That's 3 votes for the fuel additive & 2 for the engine quieting down with time. I wonder how someone might go about finding out the history of the product; build where, shipped there, etc.

Car Doc · May 7, 2010

Fwtw I even pulled my injectors and stood and watched the pump shop test them and they were within a few pounds of each other and right on spec so no problem there, thinking I had a weak injector causing the knocking.

My engine quits knocking now about 5 seconds after firing it up, sometimes doesn't even knock at all instead of finally quitting before after its completely warmed up. (talking about the hard knock not the normal diesel noise)

Its really satisfying to just add something that actually works (PS) and it doesn't cost much another plus. I am real happy with my engine now that its not embarrassing to have someone listen to it. ymmv good luck hope it works for you too btw my motor was just overhauled probably 65 hours ago.

Steve