JD 318

[BRAD ENGLUND]

I have an JD 318 riding lawn mower. The engin is an Onen. One of the cylinders does not have compression. It was runnig fine before that.

I talked to a small engine house. There the guy said it could be a stulked valve. Is that what it is or is it s combination of both? What do I need to do and were do i can i buy parts of it.

Any help will be greatly appreciated.

 

[lucas boy]

napa used to have engine parts for the cck

 

[joe csuti]

First thing to do is get mod number of eng off id plate,then goto ebay & type onan manual in search and buy a service/repair manual for series eng you have & study repair/troubleshooting charts as to 1 or more possible causes of your problem,then start going over eng to locate problem,it probably is a stuck valve/blown head gasket causeing problem,in either case you'll have to remove sheetmetal covers on eng & pull head on cyl with no compression,just to confirm head gasket not blown & valve(s)not stuck open,for parts check yellow pages for a cummins dealer as they now own onan,or take mod spec/type #'s to local mower shop & see if they can lookup & order gaskets/parts needed.

 

[jd4430]

the 318's has either B43G ot the later ones had a P218. IF there's no compression, either the valve is stuck, valve seat is loose or rod broke. Pull the head off and you should be bale to tell
Brad

 

[BRAD ENGLUND]

Thanks for all fo your help. I will try and do all of those things you said to do. Thanks again

 

[Billy Shafer]

Before yo spend any money. Take the head off and check the valves. May be a stuck valve or seat loose. Could also just be some carbon that has broken off holding the valve open. I have worked with Onan since 1980,now a retired Onan tech. Have the manuals and will be glad to help you.

 

[BRAD ENGLUND]

How do I know if the seats loose and how do I fix it? The valve I know that I need to take those out and clean with some emery cloth. Once I figure what is wrong with it what is the sequence to tighten the bolts down on the head?

I appreciate all the help that you have given me. Thanks again Brad

 

[Billy Shafer]

If the seat is loose you will be able to see it. Takes a machine shop to replace one. Need to know what engine you have to give you the head bolt readings.

 

[BRAD ENGLUND]

The engine # is B43-GA018/4174C. I took off the head the valves move freely. The valves have some carbon build up. Is that normal and should I clean this up while I have it this fare. The cylinder is not moving. I can push it all the way back if I hold it in and turn the engine over the cylinder will kick back to me. What do I need to do now? Take the oil pan off and go from their?

Thanks again for all of your help. Brad

 

[shinnery]

The cylinder should not move, Pistons move. sounds like you have a broken rod or piston or both $$$$.
Bryce

 

[Billy Shafer]

Sorry for the delay. If the piston will not move then yes you have a broken rod. You will need to remove the oil pan to check it out.

 

[BRAD ENGLUND]

I took the head off and the oil pane off. I have the parts on order. The only thing that I need now is in what order do I need to tighten the head bolts down and how tight? Also how tight and what order do I need to tighten the oil pan down to.

Thanks for all your help again.
brad

 

[Billy Shafer]

Email me and I can send you the information sheets you need. [email protected]