new craftsman GT6000 Kohler eng issue

[SPIKER]

Hi All:

just got my NEW 54" GT 6K with 54" deck & the 26HP Kohler Commander Pro engine. The engine seems to be running rough & has a sound I would say is a tight/loose valve issue.
It runs OK at speed but seems to have a sound I would best describe as a exhaust leak or a valve staying stuck open slightly almost a POPPING type sound. Also it seems to have less power than my 20HP briggs and it is 10 years old. First time mowing this week I ran it thru some 8" grass & it barely cut it at a crawl I had to stop often to let the engine pull back up some RPM. I called service and have them coming up to check on it but that will not be until near end of month. I thought it would be better to ask here and see if anyone had thoughts & ideas, I dont want to keep running it if there could be some damage that could happen. I got out my old 20HP 46" mower and went right thru the grass with a week more growth on it and didnt have an issue at all it mowed fine. The woman rode the NEW mower and had same issue I had had to keep slowing down & let engine clear up.

not smoking or burning oil seems to be right oil level too. I am not pulling plugs as it is under warranty and dont want the tech to say I did something... It will take them till end of month to come look at it.

thanks for thoughts comments and items to look at. Should I park it and only use the old one, (trans-axle is about out of it 10 yrs old Murry / Quality Farm & Fleet unit perliyss .)

mark

[tcartwri]

On my B&S 24hp it was the valves sticking in the guides. It would cause a popping, intermittent rough running and eventually a snapped exhaust pushrod. Had to change the head, and it has been golden ever since. The valves ticked on this head right from new, and I got about 150 hours out of it before I changed the head.

This was on a Craftsman GT5000.

[Jim Thompson]

Hi All:

just got my NEW 54" GT 6K with 54" deck & the 26HP Kohler Commander Pro engine. The engine seems to be running rough & has a sound I would say is a tight/loose valve issue.
It runs OK at speed but seems to have a sound I would best describe as a exhaust leak or a valve staying stuck open slightly almost a POPPING type sound. Also it seems to have less power than my 20HP briggs and it is 10 years old. First time mowing this week I ran it thru some 8" grass & it barely cut it at a crawl I had to stop often to let the engine pull back up some RPM. I called service and have them coming up to check on it but that will not be until near end of month. I thought it would be better to ask here and see if anyone had thoughts & ideas, I dont want to keep running it if there could be some damage that could happen. I got out my old 20HP 46" mower and went right thru the grass with a week more growth on it and didnt have an issue at all it mowed fine. The woman rode the NEW mower and had same issue I had had to keep slowing down & let engine clear up.

not smoking or burning oil seems to be right oil level too. I am not pulling plugs as it is under warranty and dont want the tech to say I did something... It will take them till end of month to come look at it.

thanks for thoughts comments and items to look at. Should I park it and only use the old one, (trans-axle is about out of it 10 yrs old Murry / Quality Farm & Fleet unit perliyss .)

mark

It may have a blown head gasket. My neighbor has a similar mower that's about 6 years old. Sears replaced the engine once and i replaced one head gasket twice and the cam once. Hasn't had any issues in a couple of years. Has around 700 hours on the machine.

Jim

[SPIKER]

Thanks guys so far: I have a service tech coming out but not until end of the month so I will need to mow and will try using it as is and maybe take it back for an exchange...

Mark