GC Series - 23 or 25 HP from the same size engine: How do they do that?

[Snobdds]

fuel shims? I see no reference to any shimming in the injector pump, delivery valves and Springs, or governor ,etc are all showing the same throughout there's no deciphering between models whatsoever. If you have anything you could post to show I would be interested and making notes of it. From what I'm seeing there's nothing that deciphers the 1723 hp from the 1725 but RPMs so I'm just going to go with that

Of course there are fuel shims...go look it up in the parts book like I did and you will see different fuel shims. I have no idea where your getting your info...

In fact the 1715/1720 use a different injection pump as noted by the different part numbers

 

[Dmacleo]

That's what I'm thinking also, the 25 models are running at a higher RPM at PTO speed = more horsepower you would think. I wouldn't be afraid on a 23 model to run RPMs/PTO speed a little faster I do it at work all the time never a problem with anything

540 is just like a speed limit sign.
a suggested MINIMUM speed LOL

 

[daman1]

Part numbers don't always tell the story I've seen it a hundred times before . From my service manual my dealer gave me when I bought my new tractor shim's may only be need did to adjust pressure if there's a problem now I see that's for a 1710 and 1720 is that going to be different from the 23 and5 series

 

[daman1]

540 is just like a speed limit sign.
a suggested MINIMUM speed LOL

Yup ha

 

[Snobdds]

Fuel shims do not adjust fuel pressure...

Fuel shims adjust injector to cam timing. Which does affect power settings.

 

[daman1]

Fuel shims do not adjust fuel pressure...

Fuel shims adjust injector to cam timing. Which does affect power settings.

Thanks I see no mention of that in that section anything talking about timing and injector pump, etc Anything talking about timing and injector pump had no deciphering between the two.

I'm not going to worry too much more about it next time I head to AGCO my dealer for parts I'm just going to chat with Jim.

 

[Snobdds]

Thanks I see no mention of that in that section anything talking about timing and injector pump, etc Anything talking about timing and injector pump had no deciphering between the two.

I'm not going to worry too much more about it next time I head to AGCO my dealer for parts I'm just going to chat with Jim.

The service manual is vage, probably on purpose, for the injection pump. It's not something homeowner joe should really be messing with. Very few people understand injection pumps, to the point they should be changing fuel shims and governor screw settings.

The 25hp versions at the end of the day get more fuel (injection pump), more RPM's and different internal gearing to feed the power to the pumps and PTO. The diesel motor needs three things; air, fuel and compression. If air and compression is constant between the two versions, the only other variable to change is fuel. Pretty basic stuff.

 

[daman1]

The service manual is vage, probably on purpose, for the injection pump. It's not something homeowner joe should really be messing with. Very few people understand injection pumps, to the point they should be changing fuel shims and governor screw settings.

The 25hp versions at the end of the day get more fuel (injection pump), more RPM's and different internal gearing to feed the power to the pumps and PTO. The diesel motor needs three things; air, fuel and compression. If air and compression is constant between the two versions, the only other variable to change is fuel. Pretty basic stuff.

Right yup thanks,

I did notice when it comes to the 23 and the 25 vs what was posted above with the 1705 and 1720 injection pump and injectors are basically exactly the same part number with the exception to the injector pump p/n, one of the middle numbers only one digit is different and that could be nothing significant, the fuel pump shim part numbers are exactly the same also.

So maybe the difference is how the injector pump base is shimmed, and that's what I'm going to ask next time I'm there.

 

[Rob2310]

I've had each version of GC compacts, GC2310, GC2610, GC 1710 and and the newest one. I went with the GC 1710 because of the difference in RPM'S, as I thought I would have longer longevity with turning less RMP's. After a couple weeks, I missed the "power" of the GC2610. I took a dremel tool and carefully removed the bullet looking thing on the throttle linkage at the pump. I then simply turned the nuts to increase the engine RPM. I ran that tractor for over 1000 hours and never had an issue. I would have bought my new one in the 23hp version, but I wanted the nicer seat with arm rests. The difference is in the gearing of the PTO. I LOVED the GC1710 with the RPM's turned up. You could over ride the 540 PTO when needed brush hogging and my ground speed was faster when making the mad rush to the barn in a rain storm. It was simply the best Massey I've owned. I also increased the pressure a "few" pounds on that machine, but never had an issue.

 

[daman1]

I've had each version of GC compacts, GC2310, GC2610, GC 1710 and and the newest one. I went with the GC 1710 because of the difference in RPM'S, as I thought I would have longer longevity with turning less RMP's. After a couple weeks, I missed the "power" of the GC2610. I took a dremel tool and carefully removed the bullet looking thing on the throttle linkage at the pump. I then simply turned the nuts to increase the engine RPM. I ran that tractor for over 1000 hours and never had an issue. I would have bought my new one in the 23hp version, but I wanted the nicer seat with arm rests. The difference is in the gearing of the PTO. I LOVED the GC1710 with the RPM's turned up. You could over ride the 540 PTO when needed brush hogging and my ground speed was faster when making the mad rush to the barn in a rain storm. It was simply the best Massey I've owned. I also increased the pressure a "few" pounds on that machine, but never had an issue.

Thanks Rob for your insight, where did you set your rpm's?. I've heard of guys doing that and seeing a nice increases in HP by just rasing rpm's to 3000, I'm not touching mine because its brand new and under factory warranty and it's factory set to 2850ish at present so its close, I probably will after that warranty is up, i checked hydrolics and factory has it set right around 2000psi so that's good for now.

from what I can tell with definite comparison the 25's are geared different, they need more.. rpm to achieve 540pto. More rpm more power.

 

[fxdb96]

I've had (3) of these machine. Two 23HP and my latest one is the 25HP. For blowing snow with a front mount blower - I see a noticeable difference in power / bogging. With the 25HP model (different torque too) the blower almost never makes the tractor bog down. If my ground speed is too fast - the snow just spills out the sides of the blower. With the 23HP it was always on the edge of bogging down and I had to constantly monitor my ground speed. Not a huge deal - but in my experience the 25HP is nice to have. I did my research and there are differences to injection pump at a min. Some of the dealers try to convince folks there is a simple RPM difference to get the HP - not true.

 

[daman1]

I've had (3) of these machine. Two 23HP and my latest one is the 25HP. For blowing snow with a front mount blower - I see a noticeable difference in power / bogging. With the 25HP model (different torque too) the blower almost never makes the tractor bog down. If my ground speed is too fast - the snow just spills out the sides of the blower. With the 23HP it was always on the edge of bogging down and I had to constantly monitor my ground speed. Not a huge deal - but in my experience the 25HP is nice to have. I did my research and there are differences to injection pump at a min. Some of the dealers try to convince folks there is a simple RPM difference to get the HP - not true.

Thanks, would you mind posting up what your research found to be some differences?

 

[MXD]

I've had (3) of these machine. Two 23HP and my latest one is the 25HP. For blowing snow with a front mount blower - I see a noticeable difference in power / bogging. With the 25HP model (different torque too) the blower almost never makes the tractor bog down. If my ground speed is too fast - the snow just spills out the sides of the blower. With the 23HP it was always on the edge of bogging down and I had to constantly monitor my ground speed. Not a huge deal - but in my experience the 25HP is nice to have. I did my research and there are differences to injection pump at a min. Some of the dealers try to convince folks there is a simple RPM difference to get the HP - not true.

This bums me out because my dealer convinced me that there would be no noticeable difference as the PTO HP was almost identical on both (18.3 I think he said?) so I went with the 1723E. One of the first things I noticed about the snow blower was that it was really sensitive to speed and it bogged the tractor easier than I thought it would.

 

[daman1]

This bums me out because my dealer convinced me that there would be no noticeable difference as the PTO HP was almost identical on both (18.3 I think he said?) so I went with the 1723E. One of the first things I noticed about the snow blower was that it was really sensitive to speed and it bogged the tractor easier than I thought it would.

Well its only just over 1 pto hp(18.3 vs. 19.6) so i cant see how that would make a huge difference.

 

[Rob2310]

I bumped it up to a little over 3000 rpm's.

 

[daman1]

I bumped it up to a little over 3000 rpm's.

Thanks Rob

 

[Frankenkubota]

My dealer told me the only difference in engines regarding the MX 5200, 5600? and 5800 was a bigger turbo.

 

[Snobdds]

I've had (3) of these machine. Two 23HP and my latest one is the 25HP. For blowing snow with a front mount blower - I see a noticeable difference in power / bogging. With the 25HP model (different torque too) the blower almost never makes the tractor bog down. If my ground speed is too fast - the snow just spills out the sides of the blower. With the 23HP it was always on the edge of bogging down and I had to constantly monitor my ground speed. Not a huge deal - but in my experience the 25HP is nice to have. I did my research and there are differences to injection pump at a min. Some of the dealers try to convince folks there is a simple RPM difference to get the HP - not true.

True, more RPM does not equal more power.

Anyone who has looked at a torque curve could easily see the diminishing returns at the higher RPMS.

More fuel = more power. Same as it's always been. There is a reason the diesel power guys do all they can to shove more fuel into the motor. However, without increase in air flow, it's just throwing black smoke. Fuel and air is the not so secret to more power.

GC have fixed air flow, so they put more fuel and they get more power. Then they have to reduce the gear size in the HST to get more PTO power. It's simple really.

 

[daman1]

True, more RPM does not equal more power.

Anyone who has looked at a torque curve could easily see the diminishing returns at the higher RPMS.

More fuel = more power. Same as it's always been. There is a reason the diesel power guys do all they can to shove more fuel into the motor. However, without increase in air flow, it's just throwing black smoke. Fuel and air is the not so secret to more power.

GC have fixed air flow, so they put more fuel and they get more power. Then they have to reduce the gear size in the HST to get more PTO power. It's simple really.

There IS a fuel screw on top of the injector pump to add more fuel that is not accessible there's a tamper resistant plug you would have to remove. it very well could be the 25's are set higher but the serivice manual doesn't state any settings for that.

 

[Snobdds]

There IS a fuel screw on top of the injector pump to add more fuel that is not accessible there's a tamper resistant plug you would have to remove. it very well could be the 25's are set higher but the serivice manual doesn't state any settings for that.

I would advise anyone without extensive knowledge of how injection timing, fuel shims, and injector pulse width works...to not adjust their fuel screw.