Hello, this 12.5 motor spins freely without the spark plug with the plug back in it is hard to turn by hand and with the eletric starter I put gas in the carburator but it backfires thru the carburator when you crank it I remover the OHV valve cover to see if the valves are working they seem to be working I did notice the exsalst valve slighty opens on the compression stroke then closes half way to top dead center I do get spark and my compression is 70 PSI any Ideas ?? please
Thanks

Hi Brian and When did this start happening, was it all of a sudden, after hitting a rock with the mower, gradually over time, or when you started up for the spring?

Do you know the year / model number of you 212-5? Not sure if that had a briggs or Kaw engine on them?

Thanks for replying. I bought it used and it had been sitting for a long time theres not alot of small rideing mowers in this part of california and this is one of the ones that did not cost much, But now that I have it I like it ! the orginal owner sayed it ran than stoped and he bought a new one the mower deck is gone but I was going to pull a small cart with it. the model no. is 32120502 and the motor is a 12.5 power plus model no. e125v-w/n096-40 part no. 116799 I dont see any markings that say what it is but it has a presureisd oil filter on it . the filter says onan on it partstree.com says its a 1991
Thanks!
brian

Well it is a 1991 212-5 with an Onan engine on it. I don't know much about this one, but I'll try for the standard answers. Since you have ok compression, you should check the flywheel to see if the key is sheered. Perhaps the previous owner hit something knocking the key out. If that is ok, check to be sure that the carb is clean and mounted tightly to the intake manifold and that is mounted tightly to the engine.

I can't be of much more help than that, but it will give places to start.

Ok, thanks now that could be a possabe I will check it today I dont see much on the internet on Onan I think they use them on welders On the flywheel part that makes the spark should line up with the coil at top dead center so I will check that also
Thanks!
Brian

hi Brian, you can download an operators manual, an Onan engine manual, and a BIG electrical demystification guide from Toro for your tractor. Go to:

https://lookup3.toro.com/request/request.cfm

Put 32-12o502 as model number exactly like I typed it and riding mower for product type

Ok, thanks Buzz I will look at them today. Nylyon thanks for the sugestions I took off the flywheel last evening and the pin is in good shape but it still kinna hard to spin the motor I am going to take off the oil filter and see if theres any metal in it and with the help of the work manual I can take the bottom off of the motor and look at the cam and gearing I think thats were the problem is.
Thanks for the help !!
Brian

All right! got all the info I needed I suspect the" compression release system" the book says its usely a falty spring on the cam gear that holds the exsalst valve open untill it reaches running speed thats why it is so hard to turn with the spark plug in !! I will keep you guys posted

Thanks!!
Brian