2009 RTV900g speed issue

Bigrox

New member
Hi,
I am looking for some direction / wisdom from you good people.
I have read alot of the threads here and in other sites and have tried many of the suggested remedies. I have just acquired a RTV900G at auction with 2700 hours. I didn't have the chance to drive it much after getting it and wanted to change oils etcetera. It appeared to come from someone who looked after it. All nuts and bolts had rotation indictor marks although the dates on the filters were a few years old.

When taking it for a test drive after doing the servicing etcetera I have trouble getting any speed out of it. The speed on flat concrete / pavement in low gear is apporximately 8 mph, Medium is around 9 mph and in high it is 10 -11 mph. Reverse is actually the fastest at around 12 mph. These readings are from the speedometer however they feel about correct. I am fairly confident that the speed was an issue before I did the servicing I just didn't drive it far enough or watch the speedometer to be 100% sure.
On jack stands the speed does build up to 25 mph, even 30 mph in high, however this takes a minute or so and builds very slowly.

In relation to the transmission:

I have changed all of the oils and filters using Genuine filters and UDT oil.
I have changed the 3 valve plates and they did have some wear. The pumps and swash plates looked ok visually.
I did release the coast valve 1 1/2 turns as it originally gave you whiplash when you took your foot off the accelerator.
The throttle and transmission linkages all look tight / firm.
I have checked for brake / wheel drag and it does roll slowly down a slight slope when in neutral. When you do try an rotate the rear wheels on jack stands there is some resistance and if you push the RTV when on the ground there is some as well. I am thinking this is just the transmission being engaged even though it is neutral. (as I mentioned it rolls down a slight slope slowly in neurtal).

I have done some other things that I assume wont effect the speed:
New front axles
New injectors
A couple of new switches (oil pressure and neutral sensor)
New alternator and starter
Checked the spark arrester was clear

The machine "could" have come from an airport and it has been suggested that a speed limitor may have been fitted or some other way of restricting the speed. I can't see any add-on device and would not know where you would restrict it to the same (ish) speed in all gears on a hydrostatic transmission.

Sorry for the long read, I have spent hours reading threads, looking at Messicks diagrams, looking through the WSM and tinkering. To me this sounds like oil flow or pressure which is why I swapped out the valve plates however this had little effect (actually it may have made things slightly worse but that might just be my disappointment that it didn't work).

Any thoughts, advice or recommendations would be appreciated. I would like to say I'm a bit handy, just dont know if I could or want to do a rebuild of the transmission.

Thank you in advance, I'm off to have a beer or two and stare stupidly at the back end of an RTV again.
 
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did you check the engine max loaded and no load rpm? also check clean remove or replace the spark arrestor in the tailpipe. adjust the max no load rpm to 3800 rpm and 3600 loaded stalled transmission hot oil in the trans.
 
Hi Aurthuritis,

Thank you for your response. I did check the spark arrester before the original post.

I have managed to get my hands on a portable tachometer as I don’t have one on the RTV.

I took some readings while I had the machine on axle stands. I got some readings at around 3,300 RPM. Had trouble holding the tachometer and pressing the accelerator.

The readings I took are:

around 3,300 rpm in low the speedo read 8 mph
around 3,300 rpm in medium the speedo read 16 mph
around 3,300 rpm in high the speedo read 22 mph
and
around 3,300 rpm in reverse the speedo read 10 mph

If I can find anyone I trust to drive it while I try and hold the portable tachometer I’ll take some reading under load and post them here.
 
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your high idle is to low. with the machine in neutral parking brake locked run the foot feed all the way against the stop on the floor and check the rpm. also a good idea to check with the engine off and the foot feed all the way against the stop bolt on the floor then check to see if the idle control arm on the injection pump is against the stop on the pump? if it isn't against the stop on the idle control arm then simply adjust the foot feed stop bolt to allow more travel or adjust the cable from the foot feed to the idle control arm until it hits the stop on the pump. if all of this is ok and your high idle is still low then adjust the stop on the fuel pump idle control arm until your max no load rpm is above 3600 rpm not to exceed 3800 rpm.
 
HI Aurthuritis,
I have checked the Throttle and accelerator cables and they both need replacing. I have adjusted them up completely and there is still some slack in the cables. The maximum RPM I am at now is just over 3,400.

Waiting for new cables and time to install them.

Thank you for your advice. I will let you know when I get the cables installed and the RPM upto 3,600 or just over.
 
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