Murray Ultra won't mow and move at the same time

[fullmetalone]

I have a murray ultra 13hp that i swapped a briggs 17hp motor onto. The time came to change the blades yesterday, so i did that, and now the mower won't move and move at the same time. It moves fine with the blades disengaged, and mows as long is it is stationary. When i try to mow while moving the blades slowly spin less and less until they stop...Thanks for your help.

 

[reddragon]

sounds like your blade belt is too small...and maybe your tranny belt is too big

 

[fullmetalone]

i'll check that out. i got the blade belt adjusted so it will move and mow at the same time now! but it just dies when i have the blades going and the mower moving now! argh, my good deal is starting to look like a very bad deal.

 

[reddragon]

what'd you find?