Red520 9 #1 Posted September 28, 2017 My 1995 520H is losing power when going uphill. I have to push the hydro lever forward to get up some hills that it normally went up without issue. If I'm on a hill and use reverse it seems to work fine. It has been in the 90s here temp wise but it worked before without issue in that heat. Tranny oil is nice and clean but I don't know when the filter was changed last. I purchased it a year ago. Also the drive belt is almost touching top to the bottom under the tension pulley. I was told to make sure the motor was all the way forward on the frame but I do not see any slots in which to move it. I replaced the drive belt, idler pulley and tension spring a few months ago. Share this post Link to post Share on other sites
Skipper 1,788 #2 Posted September 28, 2017 (edited) Tir it to a tree and see if it can spin the tires. If not check the belt drives the hydro unit. If it does, then you know where to look further If you are sure the fluids are OK, and the filter is OK, then i would guess the hydro unit is tired. Edited September 28, 2017 by Skipper Share this post Link to post Share on other sites
Kurt-NEPA 755 #3 Posted September 28, 2017 I was thinking the same as Skipper. The tree test will tell a lot. The tires should spin. Share this post Link to post Share on other sites
520hC-120 136 #4 Posted September 28, 2017 (edited) My C-120 did the same thing uphill, given it does not have original 12 horse ( has 10 horse ) but I had my mechanic rebuild the carb and now it is fine and does everything like its suppposed to do, ( it is an automatic ) Edited September 28, 2017 by 520hC-120 1 Share this post Link to post Share on other sites
DougC 2,641 #5 Posted September 28, 2017 Use a large tree. My 520's with tire chains on turf tires would dig holes into the ground very quickly........... We wouldn't you to pull a tree down on your head. Share this post Link to post Share on other sites
Ed Kennell 38,703 #6 Posted September 28, 2017 Is the engine losing RPM when you go up hill but not when in reverse? If this is the case, I would check the fuel pump output. If it is not losing RPM but just slowing ground speed, then the belt is slipping or the tranny is tired. 2 Share this post Link to post Share on other sites
roadapples 6,983 #7 Posted September 29, 2017 If you don't know when the filter was changed, it's time to change it... 1 Share this post Link to post Share on other sites
Red520 9 #8 Posted October 18, 2017 I changed the oil and filter yesterday and it seemed to help some but power loss is still there going uphill. When I picked up the filter I spoke with the local Toro guy and he said changing the filter was a good start. He said if that doesn't work then there is a plate inside the pump that is worn out. He said that they are noted to wear out after some time. I asked if it was a major job to change it and he said yes. The plate name started with a W but I can't remember what he called it. Anyone have any experience at changing that plate. I am a good mechanic but not sure if it is worth trying to fix. Share this post Link to post Share on other sites