Backfires and looses power when pto engaged and moving

[GunnerBob]

New guy here..... Cub Cadet Tank with Kohler Command 27 Engine starts a little difficult but runs well. When I engage the PTO engine still runs well. But when I move forward or backward I get a loss of power and backfiring.
I've cleaned out carb, plugs, checked ignition, replaced fuel solonoid.....what am I missing? Without the PTO engaged I can run it around the property with no problem. Scratching my head....

 

[Rivets]

Check you valve clearances.

 

[GunnerBob]

thanks....also checked all the spindles and pulleys and found the center blade was loose...tightened it and will check the valve clearances.

 

[mikebarber]

Can you check and see if the carburetor is loose on the manifold or the manifold is loose on the engine ?? with the engine running try moving the tip of an UNLIT gas flowing propane torch around the gasket areas of the carb and the manifold even sitting still at low power if there is a leak you will hear engine rpm change if it does you have a leaking gasket

 

[mistermowerman]

New guy here..... Cub Cadet Tank with Kohler Command 27 Engine starts a little difficult but runs well. When I engage the PTO engine still runs well. But when I move forward or backward I get a loss of power and backfiring.
I've cleaned out carb, plugs, checked ignition, replaced fuel solonoid.....what am I missing? Without the PTO engaged I can run it around the property with no problem. Scratching my head....

Hello, it may be a strange thing to say but i would recommend that you check your seat switch and the switch on your bag as what can happen is if you have a bad connection or switch out of adjustment as you engage your deck or when you are using the mower your safety cut out is going on and off causing the engine to backfire. Gary

 

[GunnerBob]

Hello, it may be a strange thing to say but i would recommend that you check your seat switch and the switch on your bag as what can happen is if you have a bad connection or switch out of adjustment as you engage your deck or when you are using the mower your safety cut out is going on and off causing the engine to backfire. Gary

Thanks Gary.... jumped the seat switch and found the break switch failing....also thing my middle spindle is failing....pulled it today and it seems dry and it spins but not feeling smooth...maybe dirt but the bearing moves up and down a little bit.

 

[GunnerBob]

Can you check and see if the carburetor is loose on the manifold or the manifold is loose on the engine ?? with the engine running try moving the tip of an UNLIT gas flowing propane torch around the gasket areas of the carb and the manifold even sitting still at low power if there is a leak you will hear engine rpm change if it does you have a leaking gasket

good idea.... I tightened everything up and it runs better.... now the center spindle I think has gone bad.... could have been a bigger issue with the pull of RPM's when I tried to mow. A little play in the bearing up and down.

 

[bertsmobile1]

Yes you are correct.
There should be no play up & down in a spindle bearing so time to replace it.
Considering the price of bearings compared to the price of decks, spindle assemblies & blades, it would be pudient to replace all of them in one hit.
Do not try to remove the spindle housing, they usually break .
Take off the top nut while holding the blade, tap the spindle through the housing.
The bottom bearing usually comes off with the spindle and the top usually stays in the housing .
But good quality BOXED bearings from a bearing supplier, not an Amazon surplus/defective/ low quality rubbish supplier unless you want to practice doing this often.
I usually fit the lower on the spindle then warm the housing and fit the bottom , put a brick under the blade then tap the top bearing in .
Tales about 20 minutes a hit, start to finish.

 

[mistermowerman]

Thanks Gary.... jumped the seat switch and found the break switch failing....also thing my middle spindle is failing....pulled it today and it seems dry and it spins but not feeling smooth...maybe dirt but the bearing moves up and down a little bit.

Glad to help.