MTD YARD MARCHINES 638 RL - PROBLEM RUNNING WITH BLADES DOWN

[blackbirdfly]

Hello,

I just bought a used MTD Yard Machines 638 RL Riding mower. It looks practically brand new, not used very much (as the owner suggested). It starts fine, and runs fine when the blade is not down. When we put the blade down, the machine struggles and will only work for about 10 seconds before stopping (not shutting off completely, just will not go anymore) or it will stop then jerk forward for another few seconds. It will not consistently run with the blade down.

Anyone have any ideas what the problem could be?

THANKS!!

 

[Fish]

Just for a test, take off the blade belt and see how it behaves under the same conditions, it it doesn't bog down and runs good, then you have a problem somewhere on the deck, if you don't, then you have a switch problem. Also post the model numbers off of the tag under/behind the seat.