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Discussion Starter · #1 ·
Hi all,

Just wondering what experiences anyone has had from increasing their engine RPMs that would also have taken their input RPMs for their hydrostatic units above the 3000rpm max listed on the hydro gear website.

I have a Toro Z5200K (25HP Kohler)that was factory set at 2700RPMs.
This was fairly ordinary in cutting performance and I have just bumped it up to 3000 which has indeed helped on the cutting side.
I see that my hydro reservoir seems to catch a little more oil in the expansion tank now but that is about all that has "apparently" changed on that side. Will more RPMs strip more oil away from the internal pump? That is the only thing I can think at this point in time for the EZT and ZT2800(uncharged) units.


Risso

(just joined...my first post from "Down Under")
 

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Hi Risso, thanks for joining up and asking your question. I don't have experience of the sort you're looking for, but right off hand I'm inclined to think Toro has a reason for setting the RPM where they did.

I'm sure there will be others who have more insight into your question.
 

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Hi Risso, welcome, and thanks for joining.

Generally OPE manufactures govern the full throttle speed of their engines for an equal balance of peak performance and longevity- typically being the more heavily weighed of the two. My guess is that the reason why you're seeing more oil in the expansion tank is due to increased temps. In terms of stripping away more oil from the pump, I would say that it is a possibility, yes. Higher RPM's can increase the chances of oil loss so it would be something that I would be keeping a close eye on.

You can take this with a grain of salt as this is just from my experience talking with a service adviser at an OPE dealership about this topic, but he confided that while it can "speed up" mowing times, it does decrease of the operation life of machines over stock. How much, I don't know. If you don't plan to resell it but run it into the ground then it might not be a big factor.
:2cents:
 

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Discussion Starter · #4 ·
Thanks very much for the responses. I am not too worried about the extra revs on the engine. I am fairly sure this was set on the lower side to meet noise / emission requirements (2900rpm CE 105 decibels) and to keep under the 3000 max input speed from HG. I have read on a few other sites that many people are running their engines on their ZTR's at near 3600 rpms (or tuning them up to this) and speaking directly to several Australian dealerships they state they would commonly set this mowers engine between 3200 - 3600rpms.
I guess time will tell. Thanks again.

Risso
 

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Well, keep and eye on things, and let us know how things go. Your experience and first hand knowledge would be great to share.
 

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Discussion Starter · #6 ·
Well I had a call today from a "Kohler" rep here in Australia and he has stated that the original 2900RPM setting is for emission and noise standards which Kohler ( and other engine manufacturers) must comply with when they export their engines (SV830s-0013)outside country of origin.

So all good to ramp up the revs on the engine....just need to reduce the size of the pulley that drives the belt on the hydro units to keep the input speed to around or under the 3000rpm mark.

And the rep tried to sell me a new SV730 motor for $3000 AUD....anyone know how that stacks up locally in the U.S.?
 

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They want $2340 for a Kohler Courage SV730 ?! :eek: That engine goes for $800 or less over here, and they have a reputation for catastrophic failure. There's been a lot of thrown rods and cracked blocks on Courage twins. Either way, that price is around 3 times what that engine usually goes for new.
 

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Discussion Starter · #9 ·
Ha, yeah figures. I have heard a bit of noise about the Kohler Courage engines on different sites. I have 220hrs on the SV830 at present and alls good but it has hardly been working given the set RPMs:)
Living in Australia is great except when it comes to the prices for many items. Don't get me started on the price for parts for my Ford Explorer!!!
Just recently imported all shocks and springs from Summit for about 60% of the cost over here......that was with $400 in freight included!!!

Thanks again.
 
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