Fixup an old Case 446 for a Maine Orchard

[hydriv]

I have no clue where you heard that load of bollocks. Yes, the heads should be removed at 500 hours or earlier in order to remove any carbon build up. It is a simple procedure. Since you are a member of CCI, then go to the ENGINES section of the Service Manual division in the Tech Library and access the ONAN service manual. It will give you instructions on how to perform this task and you will not find any reference to running a hone in the bores.

Products such as Seafoam can be used to soften hard carbon. Some people use oven cleaner but you must be careful because oven cleaner will eat aluminum. The pistons and heads are aluminum. The undersides of the valves should be cleaned of any build up at the same time and then you should set the valve clearances in accordance with the manual.

Removing carbon build up is what protects the engine from damage. Diamonds are made from carbon. When carbon gets too thick on the heads and the pistons, then the two items collide and cause major stress on the connecting rods, ultimately ending in con rod failure. When you pull the heads, you will find that the cylinder walls are clean and free of any carbon. At that point, you will realize just how ridiculous that story about honing the cylinders was.

 

[JaimesBeam]

Finally got my tuneup parts. I've been scratching
my head trying to figure out how to replace the
points; the bottom of the Points/Condenser box
is beneath the engine shroud, which there doesn't
seem to be any way to remove???

Plus there is a hard hydraulic pipe going across
the back (front is front ) of the Points/Condenser
box, and another hydraulic hose that are in the way!!!

Neither the Ops manual or the Engine manual mention
how to replace the points or remove the offending tin.

What to do???

Thanks, Jim

 

[hydriv]

The man with the most knowledge about Onan's in Case tractors is Boomer.

Here is his e-mail address.

boomers_influence@yahoo.com

Give him the model number and serial number of your tractor along with the information on the engine ID tag. He will tell you exactly what you need to do.

 

[JaimesBeam]

I suppose I'll have to drill out the rivets on either side of the strip
behind the Ignition Box. Is this stock, or has someone been
monkeying with it? I guess they thought you'd never have to replace
the condenser or adjust the points!!!!

Hopefully I can replace the rivets with sheet metal screws or something.

Jim.

 

[Xfaxman]

Those are "pop rivets", that have been added. Look like 5/32 or 3/16. Just drill them out.

 

[boomers influence]

hydriv
thank you.
boomer ( the used onan engine parts guy )

 

[hydriv]

hydriv
thank you.
boomer ( the used onan engine parts guy )

No problem, Boomer. Jim is in good hands with you and perhaps can stop posting the same thread on three different forums. LOL He does have an unusual problem with this tractor because some dealer decided to put a FCV on the left side of the dash tower and modified OEM steel lines by cutting and TIG welding them back together. Apparently, one of those lines runs across the top of the Onan and is close to where the points box is located. Jim is also unsure as to whether he has to remove the front cowl to access the points box. I think that his engine has been worked on by people who should have been banned from owning any tools and therefore Jim is finding things rather frustrating to figure out when what he sees in reference literature does not quite match up to what he sees in front of him on this tractor. Perhaps a direct telephone conversation will be in order here to help this Case newcomer out of his dilemma. All the best, Boomer and I did get your PM.

 

[JaimesBeam]

I've ordered a top adjust ignition box from Boomer;
it should be much easier to get at things from above,
instead of from behind the engine.

The points and condenser don't look bad. I'm wondering
if my coil is really the culprit. Maybe I'll buy a new
SuperCoil and Pointsavers from Kirk engines!

I also have to figure out how to set the gaps and timing.
It didn't help that a couple of the online manuals I found
are incomplete, ending before the Ignition section!

Where *should* the Flow Control Valve be? It doesn't seem
like it should be on the left side as two out of the three hoses
come from the right side, and the third comes from underneath.
If you have a Flow Control Valve is a Holding Valve still usefull?

I'll detail putting this back together when I get the parts, hopefully
it will help some other poor soul in the future!

thanks, Jim.

 

[hydriv]

The Pointsaver and coil from Kirk are a good idea.

Flow control valves have been mounted on both sides of the dash tower over the years but more often on the right side than the left. If you want to clean things up, you could remove the FCV from the left side, install it on the right side, abandon all of the steel lines and have three new hoses made up at the proper length. Hoses are far easier to route than steel lines but those hoses must by 1/2 inch ID with a 3000 PSI or better Working Pressure.

Talk to Boomer regarding the setting of the timing. If you do not have his phone number, then send him an e-mail and ask him for it. If you intend to use a rototiller, then a Holding Valve can be of some benefit in preventing the tiller from pushing the tractor forward. If your property has steep hills to navigate, then a Holding Valve is a valuable asset in keeping the tractor under control.