Riding mower troubles

[pmat]

i was riding my ztr with a opposed onan 16hp and was mowing the yard like i normally do, when my engine cuts down to half speed. it was on full throttle. i wobble my way back to the garage and it totally died in the driveway, I tryed restarting it and noticed it sounded and felt different, so i took the plugs out and did a compression test, 105 in one cyl, and 0 in the other. I doubt since i lost compression so suddenly my rings are dead, even if they were id only have low compression. my moms boyfriend says it may be a snapped valve, bad spring, or snapped cam ( it has 2) but his knowledge in lawn mower engines is pretty limited, since you guys are small engine nuts, what do you think? is it worth replacing? or should i yank the 18hp twin off my utility mower. Thanks guys

 

[pmat]

I think i may have found the problem (see pic)
Got it out, impact wrenched the head back on, and have 132 psi compression

 

[lemegacool]

is that a screw in the valve opening... lol

 

[pmat]

yep it is. let this be a lesson to have your air cleaner screws very tight

 

[THE HUNTER]

you used an impact wrench to put the head on??
you should always use a torque wrench and torque to specs.

 

[pmat]

last night it was running better then ive ever seen it run before ( i got it for free a couple months ago) and today, it will not run. the pullys turn about 1 time for every 10 flywheel rotations, and it backfires like crazy. so i suppose its time to put my 18 twin with a broke governer on. but i cannot get the pullys off even with a wheel puller. any tips are appreciated. and i took the impacted head off and looked at it with a magnifing glass and its fine.

 

[theo]

Can u heat the pulleys?

theo

 

[lemegacool]

heat them or soak them in wd-40...

 

[THE HUNTER]

PBlaster is a big help, soak it in that for a few hours, then use a puller.
heating is my last resort.

 

[THE HUNTER]

oh, and make sure you lightly sand and oil the shaft before putting a pully on, it will help prevent the pullys from being a pain to get off lator.
you prob knew that already though lol.

 

[lemegacool]

if you have the budjet for it too, when installing a pulley put some locktite silver anti-seize stuff, pricey but well wort it... it's cool at the shop we have the big jars of this stuff and sometime i take some... :biggrin5:

 

[Kenny_McCormic]

Air chisel works wonders, sounds to me like it sheared a key.

 

[pmat]

heating would probabily not be a good idea considering it would heat the bottom of the pan. ive been soaking it really well with wd40, hope i can get the **** thing off tonight. and i checked the flywheel key and it is fine... that motor has a demon following it.... especially since it came from a haunted house. i have to get this fixed soon, the grass is growing, and my husquvarna has a stripped spark plug hole.

 

[Kenny_McCormic]

Key on the pulley, it happens. Just fixed a mower where that happened, previous owner must have hit a rock, mount destroyed, blade gone(probably bent and thrown out), and had to use and air chisel to remove the mount.

 

[pmat]

tonight i tried pb spray, nothing. generous amounts of wd 40, nothing. torch, nothing. air chisel, nothing. and the pully is nearly destroyed from the wheel puller. this is a HUGE pain in the

 

[pmat]

i used a sludgehammer and got it most of the way off, but i mushroomed the end of the shaft, so i cut the rest off, it was only about half an inch. i am very happy it is off now the work can begin getting the 18twin on :]