Power loss under load
 

I have a IH 105 that ran great all last season and through the winter plowing. I just put the deck back on to cut after rebuilding the mule drive and everything seamed to be working fine until I started moving. The engine started to bog down and it staled out. Thought it was bad gas I chaned it out and it helped some, but did not fix the problem. I ran with the blades off and the tractor tears aroung the yard. but as soon as there is a secondary load it bogs down. I also notice I have to keep adjusting the Hydro lever because I loose power on a grade and it picks up steed as soon as I hit the flat. Significant adjustments back and forth. I noticed a filter on the front of the trans case (only had one season so I am learning this machine) could old fluid and filder be causing my issuse? I have tried looking up the issue in the threads but I am striking out.

First off, check the belts, mule drive and pullies, Make sure all are spinning freely and nothing is binding

Tractor that tears around the yard without mower deck engaged doesn't lends to the hydro causing the engine to bog down.

It's more likely that the deck is not operating freely (bearings, belt binding/ rubbing) or that you have issues that degrades engine performance under load (fuel starvation, govenor, timing, compression, etc)

Ok checked govenor seams to be at proper adjustment. I did run it around the yard again and it is bogging with or without the deck engaged, it is just more noticable with the blades engaged. That being said I did find the mule drive belt has a twist in it on the pto drive pulley so thats one issue that will slow the motor but its obviously not the only. I also changed the copper fuel line noticed the rubber compression fittings were falling apart, so I replaced with copper compressions.

Sounds like it is starving for fuel, make sure you are getting a good flow at the carb fitting on the bowl.