If I understand, you are saying 2 decks do the same thing. So maybe not the deck?

In general, with my GT235, the deck has to be free of the grass when being engaged. Especially if starting out for the day, when everything from the last mow was not clean and has hardened. Later during the mow, it is all loose, and restarts easy, even in grass.

Main point is that resistance upon starting the deck can cause bogging down, maybe even stalling.

For me, the resistance is packed old grass and current tall grass. Once that is overcome, it runs fine.

For you, trying it with 2 different decks, the resistance may be bad bearings or some such thing from engine and pto pullley. I'm no mechanic.

Does problem happen with a clean and lubed deck that spins easy by hand (when not attached to tractor)? Happens when starting over a driveway? Then probably not the deck itself.

One thing, as a possibility, make sure the belt is not riding on the lift arm. This probably not happening, but make sure belt is cleanly going from engine pto pulley to deck pulley, without rubbing on anything.

 

It could also be the engine is down on power, possibly a dirty carb.

 

Clutch maybe?

 

just seen this on a friends D170 .Pulled spark plug wire of each side while running and it has #2 cylinder not running when #1 wire pulled
is a 26 hp B&S and it did seem to run smooth but no power with one dead cylinder ,was a dead coil and is being replaced

 

My GT225 has the 16hp Kohler and 42" deck. It bogs down pretty low on every start up, but instantly picks back up. It will never kill the engine even if I start the deck up at idle speed (something I don't regularly do).
I think you have a bad pulley bearing or something rubbing.

 

if deck is clean, lubed an easily spinning, then it is engine, loss os power; it can be bad head or improperly adjusted valve, bad head gasket, or dirty clogged up air filter, weak fuel pump or vacuum feed hose to pump or clogged crankcase ir breather, worn down spark plugs or weak or bad or improperly adjusted governor, always start deck at nearly 1/2 throttle, not idle then quickly move to full throttle------- try starting deck as i described ;.then if bad then check air filter, plugs and fuel, then go from there

 

Leland, you sound like a pro. Any thoughts on this post? Thanks!

https://www.greentractortalk.com/posts/4317945/

 

My 345 was doing the same thing a few years ago. A new PTO switch fixed it.

 

My engine runs fine but when I engage the deck the engine dies. I release the tension arm on the deck and engage it and it doesn't die so I lock the tension arm and it will run but it won't do that from a start point with the tension arm engaged

 

Was this a sudden change or gradual? I woul disconnect the pto to mower deck belt. If it still has the problem then its not the deck but if it doesn't bog down it could still be the deck athough i doubt 2 bad decks if you can turn them by hand. Does it run well otherwise like moving fwd fast. Next i would check voltage to pto and pto current. My guess with no oter data is pto bearings.