OldMachinist
Platinum Member
You said you've had the tiller 2 years, did you buy it new because the warranty is 3 years.
Cub Cadet RT65 Problem
- Thread starter Darkember33
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Bob_Bainbridge
Platinum Member
I don't know why the engine would turn freely with the plug removed and not with it installed but I have to disagree with it being a valve timing problem. When the valves are timed correctly a 4-cycle engine has maximum compression on 1 upward stroke of the piston and a 2-cycle has it on 2 upward strokes. Any valve timing problems would result in reduced compression, not more, as one or the other of the valves would be open or partially open during the compression stroke. Maybe there is a problem in the recoil starter which is magnified when the engine has good compression. Just my 2 cents.
Bob B.
Bob B.
nahfwt
Member
If the exhaust valve was stuck closed it would turn freely with the spark plug off and build excessive pressure with it in. I would inspect your cam and you should be able to see if the valves are moving freely without getting too far into it. Of course if it's still under warranty just take it in and let them deal with it.
OldMachinist
Platinum Member
If the belt broke and both valves are closed it would make it very hard to turn over with the spark plug installed.
oldmech
Gold Member
- Joined
- Dec 26, 2006
- Messages
- 468
- Location
- Quebec
- Tractor
- Two Gravely Two L One with 10 h.p Dek-Diesel engine one Grillo 107d and one BCS 735 diesel
Hi! May be a lot of oil or gas in cylinder . Gas or oil are not compressible. So when you remove plug you can start. Shut off the line of gas Remove the spark plug reverse down engine and crank for empty the cylinder. Good luck Oldmech
Bob_Bainbridge
Platinum Member
If both valves were stuck closed it would just keep compressing and expanding the same volume of air and would be unable to draw in any new air. If the exhaust valve was stuck it would compress the air and then release the pressure every time the intake opened. Oil or gas in the cylinder is a possibility. That's why they pull the props through by hand before starting the radial engines on an aircraft. They have a tendency to leak oil past the check valve into the lower cylinders and break a piston when it tries to compress the oil. I once saw the mechanics add 10 gallons of oil to a DC-6 engine, thinking it was low, and saw 10 gallons of oil pumped out on the tarmac when the engine started.
Bob B.
Bob B.
Jsamuels
New member
Hey guys I have a similar issue. I own a cub cadet 65rt. Before from time to time when you would pull the starter cord it would jam when it was compressing the motor to start.Now after letting my me few borrow it. The motor is like freely spinning. To pull the starter cord it is smooth, and you can feel the MOTOR freely spinning but won't get that hard turn that starts it. Any help would be greatly appreciated.
