^^fixed
We mow at the governed wide open throttle and blow all grass/dust off, including back blowing the radiator, everytime. x744
i can understand that if you are running in thick or tall grass. But just like you don't drive at the governed max speed of your car engine, unless you need the
maximum power output of the engine, which is what they sure advertise and have to deliver, every time..., then why have your engine at the max if you don't have to?
I'm not talking bogging along at 1500rpm, I'm talking 2000 vs 2300.
In boating taking an engine out all the way, governed or not, is called WOT, wide open throttle. Also called "on the pins".
Rarely are boats operated that way for very long.
They aren't designed to be operated at WOT from the beginning and there are maximum allowable times you can keep the throttle all the way forward.
Think the fishing boat that died on Jaws...
Most planing hull boat diesels are run at 70-90% of WOT.
I owned a pair of 8V71Ti's and even with a good cooling system they would get hot running too hard too long.
Now JD and others have to design for engines that aren't taken care of as well as some of ours. We may blow off the engine, blow out the radiator and screens every time we come back from an hour or two of mowing, but the average consumer isn't that careful. Will be lucky screens are checked at next fuel stop, whenever that is. So there has to be extra cooling capacity built in to suffer a reasonable amount of use and even abuse. And you also don't need every hp your motor produces to mow 1-2 inches of grass off the top of your lawn usually. Admittedly if grass were damp I would run engine faster to get maximum blade tip speed out of mower and therefore more air flinging the clumping grass further.
Bottom line is I wouldn't run it that fast unless conditions demanded it and usually if you keep your blades sharp, they haven't for me.
Running a snowblower takes a lot of power so I can see a similar issue with material ejection velocity and need for power. But I still wouldn't push the throttle all the way up til it can't go
further simply because usually it runs just fine at a slower speed, and I use a lot less diesel. Maybe I'm cheap but why burn more fuel than you have to?
And some trawler diesels are happy to run at 1400 all day long as long as the engine finally reaches full operating temperature.
Most smaller gas engines in my experience are governed at 3600, sometimes 3200, but 3600 of course is the rpm for generators so it's a common standard.
Anyone buying a larger standby generator knows you usually want slower rpms which also produces less noise.
Engines usually last longer going slower, total piston distance traveled I think.
Yanmar has always specialized in high speed diesels, as well as gigantic bigger than a house slow speed engines for mega tankers.
Their recreational diesels really created a fuss when they came in at 3600rpm, unheard of to the 2300 rpm crowd. There were all expected to blow up and
for sure overheat. Which they didn't if given reasonable maintenance.
Bottom line is who has put a digital tach on their JD garden tractor diesel to see what rpm it runs at full throttle? I'd like to compare that rpm level to the rpm used for the
power rating of the engine. I bet it's lower. ??
My X750 temp gauge never ever moved from the same middle position on the idiot gauge for the 600 hours I owned it.
