Cub Cadet RT65 Problem

Darkember33 · May 28, 2012

I have had this for two years w/o a problem and even used it earlier this year with no trouble, but when I attempted to use it yesterday, the pull start seemed to get "stuck". I tried engaging the drive and pushing it in an attempt to move the position of the piston, but it is still stuck. Any ideas?

If it helps I have the Honda GC190 engine.

Thanks!

JTKub · May 28, 2012

Is anything stuck under the mower? Maybe pop the self-propel belt off to make sure it's nothing binding up with the drive mechanism.

Joel

Darkember33 · May 28, 2012

Yeah, I've checked the tines and they spin freely, also the drive belt sits loose on it's pulleys.

OldMachinist · May 28, 2012

I'd check for mud dabber or mouse nests in the pull start recoil housing.

MasseyWV · May 28, 2012

JTKub said:
Is anything stuck under the mower?

http://www.cubcadet.com/webapp/wcs/stores/servlet/product_10051_14101_10229_16202_-1_600000_16202

An RT-65 is a tiller, not a mower. :laughing:

Otherwise, I agree that the pull start recoil housing is a good place to start. The spring may have broken or came loose.

Darkember33 · Jun 3, 2012

I tried taking apart the 'puller' and all looks well there. Since the piston feels like it is the problem, I removed the spark plug and tried the pull and it is fine. I put the plug back in and the same thing happens. How does one address a compression problem?

OldMachinist · Jun 3, 2012

Maybe the exhaust/muffler is clogged. I've had mud dabber wasps build nests in them before and cause problems like this on my grass trimmer.

OldMachinist · Jun 3, 2012

I just looked at the parts breakdown for your Honda engine and it has a timing belt to drive the overhead camshaft. If the belt broke or jumped time it would cause either the valves to not open or open at the wrong time.

Darkember33 · Jun 4, 2012

That would explain why it worked before lunch and after lunch gave me fits. Would that explain why it pulls proper w/o the spark plug?

Also, how screwed am I if this is the issue. I know for cars it is a death sentence...

Thank you all for your advice, it has made pulling my hair out a more pleasurable experience.

OldMachinist · Jun 5, 2012

Yes without the spark plug when the piston comes up the air can escape. If it out of time with the plug in place the valves don't open at the proper time and it makes it hard to turn over. I don't know much about small Honda engines but I doubt its like the car engines that the valves hit the pistons with the timing belt breaks.

OldMachinist · Jun 5, 2012

You said you've had the tiller 2 years, did you buy it new because the warranty is 3 years.

Bob_Bainbridge · Jun 5, 2012

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.

nahfwt · Jun 7, 2012

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 · Jun 7, 2012

If the belt broke and both valves are closed it would make it very hard to turn over with the spark plug installed.

oldmech · Jun 7, 2012

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 · Jun 7, 2012

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.

Jsamuels · May 16, 2014

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.