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Cvans

B112

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Cvans
I just picked up a B112 that was not running. I rebuilt the starter generator but now the engine has no spark. I pulled the cover off of the points and the push rod that activates the points moves very little. Maybe .015 at the most. How much should it move and how do I get the little rod out? It comes out quite a ways and then just stops dead. Also the engine is only showing about 45lbs compression which I believe to be pretty low. The rest of the tractor seems to be in pretty nice shape. Thanks for your help! Chris

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Buickgsman
I can't help you too much on the points issue, but pop the valve cover off on the side of the motor behind the carb and rotate the engine and watch to see if the valves move. The exhaust valve may be stuck. If so you may have to pop the head off and soak the valve and try to free it up. Not too big of a deal if thats what it is... but be gentle if you try to free up a stuck valve. soak the heck out of it with pb blaster first then lightly work it up and down. Then install your new head gasket and for like 6 bucks its all fixed. I hope it is that easy!! Bob

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Cvans
I think I had better tell the rest of the story. This tractor is in pretty good physical condition. The engine is a different story and here is why. Below the air filter on the carb is a large pressed in plug (ie. Welch sp? plug) that had been missing for some time before I acquired the tractor. The tractor had been used for tilling and sucked a lot of dirt into the engine. I picked it up from a relative who never used it but thought the engine had been smoking badly before he received it. He had not run it because the starter generator needed new bearings. So I would like to get it running and see what the engine needs before I decide how to proceed. That is why I need to find out how much that plunger for the points needs to move. There is a good chance that there is so much internal wear from the ingestion of dirt that I will never get the points to open properly. Thanks Bob for offering up the information. I have a Kohler in another tractor that has exactly the problem you mention. Chris

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JimDk
Chris, I acquired a 16 hp Briggs that was run for years without the breather tube attached to the carb. It is worn too badly to repair. I would guess that yours might be the same. 45# of compression is probably a good indicator of severe damage. Your best bet would be to try to pick up a good used engine, or a junk tractor with a good engine and do a swap. My B112 and B212 have both had 16 hp Briggs transplants, and work well. The extra power is nice. The 16's seem to be more avaiable than 12's. Good luck, Jim

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Cvans
Thanks for the reply Jim! Your probably right. I have a koher 17 hp twin that needs a new home but this might be a bit of a push for room. I'm not in a great hurry so I'll see what comes up. I do like the idea of variable speeds in the 3 gears. Seems like a very usable combination for garden work. Thanks again for your input. Chris

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joelk
If your only concern were the points, you can replace them with a Mega-Fire ignition module for about 15 bucks. I have one in my 12HP briggs and it works just fine. The rest of the engine I can't help you with.

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RayS
quote:
Originally posted by Cvans
Hi Joel: What triggers the Mega-Fire to keep it in time with the engine? Sounds like a cheap fix for faulty points ignitions. Chris
It hooks up to the wire coming from the coil. Not sure if that is called the primary or secondary wire. I have one on my B212 for the past 8 years with no problems. Below is a link to how it is hooked up. http://www.serviceproparts.com/index.html?lang=en-us&target=d3951.html

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johnmonkey
As for the points, the push rod wears, I have a 19d where the points barely open. I bought the replacement plunger, however, I have yet to replace it :(. As far as the mega fire, (NOTE: I am not 100% sure of the following statement). If the coil is a three leg coil (like on my 19d) the megafire will not work, they will work on a two leg coil. Can anyone verify the 3 leg vs 2 leg coil?? anyone? jh

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Cvans
Thanks Ray for the link. That is really something. A guy should have one of those on hand just in case. I'm going to check it out. Now, does anyone know how to get that points push rod out. Do I have to open up the crankcase? Thanks for all of your help!!!!! Chris

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Leroy
quote:
Originally posted by johnmonkey
As for the points, the push rod wears, I have a 19d where the points barely open. I bought the replacement plunger, however, I have yet to replace it :(. As far as the mega fire, (NOTE: I am not 100% sure of the following statement). If the coil is a three leg coil (like on my 19d) the megafire will not work, they will work on a two leg coil. Can anyone verify the 3 leg vs 2 leg coil?? anyone? jh
Is changing to a two leg coil worth the expense?

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mohrds
quote:
Originally posted by Cvans
Thanks Ray for the link. That is really something. A guy should have one of those on hand just in case. I'm going to check it out. Now, does anyone know how to get that points push rod out. Do I have to open up the crankcase? Thanks for all of your help!!!!! Chris
Funny you should ask. Zippo has a How To video on the points plunger. He is a wealth of knowledge! http://www.youtube.com/watch?v=s8a905S6zPs

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D-17_Dave
The plunger can be replaced to help the passage of oil into the points cover drowning the points and causing them to fail. However, the cause of reduced plunger movement is due to the cam lobe being too worn to push the plunger out against the points as needed. You can reduce the points gap a little on some worn engines but the points need a little air gap to avoid being burnt by debris which will reduce the life of the points. There is no fix for this other than replacing the worn cam or converting the engine to some style of electronic trigger ignition. The abuse of the engine in your description sounds like it's now a boat anchor. Might be time to look for a replacement.

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MrSteele
Boring a 16 and sleeving it back to standard is your only choice for the 16. I am in that situation right now. Your rings and likely the cylinder is /are shot, and you need to replace the rings with the unavailable oversize, as I do. Unless you luck up on eBay and find oversize you can bore to, you are out of luck with the project, unless you bore and sleeve back to standard, which is still available from Briggs. Sounds as if you need a camshaft as well, and you can likely pick up a usable engine for less than you will have in parts for the one you have.

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Leroy
quote:
Originally posted by D-17_Dave
The plunger can be replaced to help the passage of oil into the points cover drowning the points and causing them to fail. However, the cause of reduced plunger movement is due to the cam lobe being too worn to push the plunger out against the points as needed. You can reduce the points gap a little on some worn engines but the points need a little air gap to avoid being burnt by debris which will reduce the life of the points. There is no fix for this other than replacing the worn cam or converting the engine to some style of electronic trigger ignition. The abuse of the engine in your description sounds like it's now a boat anchor. Might be time to look for a replacement.
The electronic method is no doubt the best way, but what method works best with the 10 to 16 horse non magnetoed Briggs systems?

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Leroy
quote:
Originally posted by Cvans
Thanks Ray for the link. That is really something. A guy should have one of those on hand just in case. I'm going to check it out. Now, does anyone know how to get that points push rod out. Do I have to open up the crankcase? Thanks for all of your help!!!!! Chris
Here is a video by Zippo Varga that explains that procedure. [url]http://www.youtube.com/watch?v=s8a905S6zPs[/url]

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