[Steve644]

Hey everyone, just looking for some help with my Case with the 18 hp Onan. It is throwing alot of blueish smoke out the exhaust, and burning quite alot of oil. My thoughts are Pistons and rings? Maybe valves? Any help would be greatly appreciated!
Thanks

 

[Hydriv]

My suggestion would be to do the following.

- remove the heads and carry out a decarbonizing as per the service manual Pay attention to the undersides of the valves.

- set the valve lash so that you know that the valve train is opening and closing correctly.

- with the heads back on and torqued down, do a compression test

- then do a leak-down test.

That's the way to assess what's going on inside the engine.

 

[Steve644]

Thank you for the help. Now I know where to start. I am new to this website so is there instructions on how to do all that on here? I am" mechanically able" ( i guess thats the best way to say it) i just have never done those things with this motor.
Thanks

 

[Snotrocket]

What is the Serial Number and year/model of your tractor?

 

[Steve644]

give me a minute i will go grab it. Thanks

 

[Steve644]

Ok... Here are the numbers i found. The motor is NOT the original motor. Its a 1980 Case 446. PIN: 9787486. Onan motor model number: BG MS-3272A Serial number: E773 257640.

 

[Snotrocket]

Here is the engine section of the service manuals.

viewtopic.php?f=25&t=633

I'm not sure we have one for that specific engine.

I know relatively little about Onan's so I'm sure someone will be along to give you better info.

This manual here should give you a basic idea of what you're getting into.

viewtopic.php?f=25&t=633

 

[Steve644]

Thank you. According to the research that I have done, this motor came out of a Sears tractor.

 

[Snotrocket]

Where in Maine do you live? How much smoke is it blowing?

 

[Steve644]

I live in the yarmouth area. It smokes quite a bit and uses alot of oil.

 

[boomers_influence]

case446
you have a rare BG engine
3.25 bore 3.00 stroke (49.8 ci.)
rated at 18.0 h.p..

pistons and rings, still ava. (in pairs) rods and crank ???

you could install the B 48 rods and crank.
good luck. boomer( the used onan parts guy)

 

[Steve644]

Hey boomer, are you saying you think I need rods and crank? Or did I read it wrong and your saying if I needed to I could use b48 crank.
Thanks,
Steve

 

[boomers_influence]

steve
if you need to do so, you could turn it into a 18 h.p. B48M
thank you. boomer

 

[Steve644]

Thank you for the information! Any opinion where the best place to buy motor parts for my motor would be?

 

[Stewart]

My choice would be from Boomer. :thumbsup:

 

[Steve644]

Sounds good to me :thumbsup:

 

[Hydriv]

Boomer is the best but................. why get ahead of yourself?

Now is the time to do those things I mentioned so that you can DIAGNOSE what is truly wrong with the engine you have.

If you don't understand what a leakdown test is... perhaps this will help.

http://www.motorcycleproject.com/motorc ... kdown.html

We have manuals on Onan and Kohler engines in the Library that explain how to decarbonize the engines.

What else would you like to know?

 

[Steve644]

Im definitely planing on doing what you said first. Im talking about new head gaskets to start. Probably shouldnt reuse the old ones.?

 

[Hydriv]

Look at the gaskets you remove to check them for damage. If they look pretty good, then go buy a rattle can of aluminum spray paint and just before you are ready to install the heads, spray paint both sides of the gaskets. Leave them hanging up until they get tacky and then install them. Torque the head bolts down in the proper sequence outlined in the Service Manual. Those will get you by for the moment. Start your engine, let it warm up and then re-torque the head bolts. Then you can take your compression readings and conduct the leakdown test.

 

[Steve644]

Ok that sounds good. Im going to do it with in the next few days. Ill post the results as soon as im done. Thanks again