I have a Mustang 310 skid loader. This machine has a clutch which essentially pushes an idler spool into the large serpentine belt which then engages the two pumps which drive the wheels. When the clutch is not engaged, the engine runs fine and the hydraulics for the boom and bucket work fine. Now when I engage the clutch, the engine bogs down such that I can barely move the machine when I use the drive levers. This just recently occurred. I disengaged the clutch and checked the pulleys that are on the two drive pumps. They can each be turned freely by hand. They do not seem to bind up at all. When I engage the clutch, even though the engine is bogged down, the belt seems to be driving each of these pulleys easily. When I engage the left or right drive lever, The machine will move the appropriate direction and there doesn't seem to be a direction which causes the engine to bog down more than the other lever does. I changed both filters that were in the hydraulic line (one for each drive pump). The old ones looked clean and the hydraulic oil looked clear. The new filters made no difference. I changed the engine fuel filter to to make sure the engine wasn't being starved for fuel when it was under load. The old filter looked fine and the change did not correct the problem. The engagement of the clutch doesn't seem to be putting too much pressure on the belt. In fact the idler pulley seems to float back and forth by about 1/2 inch while the clutch is engaged. Does anybody have an idea of what might be causing this problem?
Help Support SkidSteer Forum:
This is definitely hydraulic. The lever pushes an idler spool into the serpentine belt which then engages two pulleys connected to two hydraulic pumps -- one for the left side and one for the right side. The drive levers for each side tie directly into these hydraulic pumps.
Rookie
Well-known member
- Joined
- Oct 24, 2010
- Messages
- 70
What engine do you have? It sounds like it could be governor related. Can you check your governor oil or is it engine lubricated?
The engine is a Kohler 18 hp gas engine. To my knowledge it does not have a hydraulic governor. We are thinking that one of the hydraulic fluid bipass lines on the high pressure side of the hydraulic valve is somehow partially plugged which would cause the Mustang to bog down when the clutch is engaged. This seems somewhat logical since the engine immediately bogs down when the clutch is engaged with the steering levers in neutral. Since the hydraulic pumps are pumping hydraulic fluid, it seems plausible that their is something blocked.
I realize this is an older post, but i was curious if you found the problem. It has probably been 20 years since we had a 310. I do remember it doing this same thing when it was cold and when it was time to replace the motor. The hydro put a lot of pull on that motor and when it got weak it would hardly go. Hopefully you were able to resolve this without that being the case, but just thought i would share our experience.
ratroket127
Member
- Joined
- Mar 30, 2011
- Messages
- 21
I had a Mustang 310 that had this issue too. Fisrtly you are 100% correct in your explanation of the drive system and I couldn't have explained it better. It is explained to me that the drive motors use 70% of the hydraulic horsepower consumed by the machine. This is the reasoning for OMC manufacturing the 310 with a drive disengagement for friendly starting in cold weather. On to the issue you are having. I'm relatively certain your carbeurator or fuel filter is obstructed. Here is how I figure: A hydraulic issue in the drives is possible but unlikely without other evident problems. (one side slow/weak, throwing belts and such) The governor in that kohler motor rarely ever screws up unless it broke(unlikely!!!) or it was tampered with. There is other carbeurator or governor adjustments that most troubleshooting guides will tell direct you to-NO! Simply if nobody fooled with it is is probably fine. I'm almost sure your machine (like Mine) sucked some debris of the bottom of the tank into the carb and blocked it from delivering all the fuel that it needs. It sounds like it is able to run fine until it needs the extra fuel to maintain the same RPM. More likely your governor is opening the throttle, the fuel isnt able to be drawn out of the plugged orifice in the carb at a porportional rate from the increased suction, your motor then dies like its out of fuel. Mine wouldnt run without being partially choked. The above explains the natural cause of the issue plausibly That carb is easy to take off, hose out with a little cleaner and reassemble. This has solved my problem. I may be wrong but i'm relatively certain its this. Good luck!!!
Gosh, I hope you are right in the idea that the carb is blocked! Something that might support that view is that last week, I went to start the 310 because it had sat for about 6 weeks. It would not start -- turned over but seemed not to be getting fuel. I put gas in the tank and tried again but still no start. I had to leave shortly after so did not get a chance to check the carb. But that brings me to a question about the throttle and governor. When I run the machine with the clutch disengaged, it runs fine. I can take the throttle to full throttle and it runs fine without any falter that might indicate poor fuel flow. When you mention the governor, are you saying that the Kohler engine has a governor that, when the clutch is engaged, allows more throttle to be applied than I can reach with the throttle control lever? Also, concerning the idea of fuel blockage. back when I posted this inquiry, I had replaced the fuel filter with a new one, all to no avail on operation. Wouldn't the fuel filter plug before the carb would? I look forward to your answers.
I had similar issues about 5 years ago. I did replace the whole carburetor body trying to troubleshoot it. Then I learned the governor failed, which is internal and like two small hammers on a swivel. I replaced it with an 18hp briggs vanguard which was a good move. Now on to the weak motor or pump issues.
Problem solved!!!! Your comments about not getting enough power from the carburator made me take a look at the engine. The Kohler engine is a 2-cylinder and when the hydraulics are not engaged, not much power is needed from the engine. It turns out that when I had the engine running without the hydraulics engaged, I checked the exhaust mufflers on the engine. One was hot and one was cold! I had a bad spark plug and one cylinder was not firing. Without hydraulics that cylinder wasn't needed. A quick change of both spark plugs and when I engaged the clutch the engine revved up nice and I had plenty of power. Such an easy solution to a problem I thought was going to be very complicated. Thanks to all who gave me input. It's great to have my Mustang 310 back!!
