Bobcat CT235 problem

[dean7777]

I have a Bobcat CT235 that when put under a load (pulling a 5 foot rotary mower) bogs down under the load. It does not do it all the time. I am mowing at 2000 rpm and it will suddenly drop to 1000 and if I do not stop the mower it will completely stall. As soon as I disconnect the power to the mower it runs fine. I have replaced the fuel and air filters. I have checked the flow of diesel to the fuel pump and I have tried loosening the fuel cap will it bogs down ( it does not help). Any suggestions?, I guess my next try will be a new fuel pump. Thanks

 

[groundcover]

Sounds like you have something wrapped around the mower shaft. Are you only losing power with the mower on ? Try running uphill under load and see if she bogs down.

 

[dean7777]

Sounds like you have something wrapped around the mower shaft. Are you only losing power with the mower on ? Try running uphill under load and see if she bogs down.

Yes I have checked the mower. I bogs down going uphill, downhill or on a level.

 

[whis]

how tall or thick is the stuff your cutting?

 

[SSdoxie]

I have a Bobcat CT235 that when put under a load (pulling a 5 foot rotary mower) bogs down under the load. It does not do it all the time. I am mowing at 2000 rpm and it will suddenly drop to 1000 and if I do not stop the mower it will completely stall. As soon as I disconnect the power to the mower it runs fine. I have replaced the fuel and air filters. I have checked the flow of diesel to the fuel pump and I have tried loosening the fuel cap will it bogs down ( it does not help). Any suggestions?, I guess my next try will be a new fuel pump. Thanks

You did not mention what gear range you are operating in or how fast you're try to go (how much pedal stoke).
The rated PTO HP on that tractor is 540 RPM @ 2520 engine RPM to achieve 26.5 PTO HP. Running @ 2000 on the tach is only 80% of the rated speed, thus about 80% of available HP. The cutter (regardless of brand) is designed for optimum blade cutting speed when PTO is at 540 RPM.
Before investing in other parts that may not be needed try this and report back:
Run engine at 2520 RPM (up to that red arrow on the tach).
Use low range with as much pedal stoke as you can and still cut. Unless the grass is very tall and thick, you should be able to run at close to full pedal.
Note: Full pedal stoke in low range equals same ground speed as 1/2 of max stroke in mid-range, yet it takes more engine power to move that same speed because the HST has to work at higher pressure to compensate for the higher gear range (torque loss).

 

[dean7777]

how tall or thick is the stuff your cutting?

Pasture and I am cutting it pretty high. I have been cutting the pasture for years with the same mower, same gear and rpm with no problems.

 

[dean7777]

SSdoxie,

I will give your advice a try. Like I told groundcover I have been cutting this pasture with the same mower, in the same gear and same rpm with no problems. I am cutting in medium at approx. 2000 rpm and cutting the pasture high, a 7 on the 3 point hitch indicator. Thanks