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My engine swap into the 3212v


rpickle

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I have been fiddling with this 3212v for a few weeks. Had it running, but the 12HP Briggs smoked quite a bit. I had a 7016h tractor sitting in the shed that I knew the engine was better, at least it didn't smoke all the time:) I swapped the 12 horse out for the 16. First thing bummer was that the oil drain plug was on the opposite side as the 12. Had to make a small cut-out in the frame so I could change the oil w/o pulling the motor! Once that was done, it just slipped right in. Wired it up and tried to crank it over. It would crank over a few times then go "clank". I could move the engine thru several revolutions by hand so I was a little puzzled. Tried a larger batter w/cables, same thing. Pulled the spark plug and it cranked over nicely. I was wondering if my starter/gen was weak so I swapped in a different one. Same thing, atleast at first. I figured out also that I wasn't getting spark. Replaced the plug and that was good. Hooked up the car battery and it cranked over much better, but it still darn near stopped on each compression stroke! It did fire up and run well after the spark was fixed. Aren't these supposed to have some kind of compression release? Also, I still cannot get the engine to shutoff with the key. This engine has the solid state module in it. I'll be posting again soon on how to get my tiller going on this, unless it is an easy setup. Rick
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Your ignition kill wire is probably not hooked up to the ignition switch, or the switch is not grounded. It usually comes from the magneto to an insulator block on the side of the engine, then from there to the ignition switch.
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That makes sense Rod. I have one wire not connected from the wire harness and from the diagram it is supposed to go to the points. I have tried grounding this wire to the points when the ignitions switch is off, but the engine continues on. So if the wire isn't connect at the switch, that could be the issue. Appreciate it. Rick
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I have a 3112H re - engined with a 16HP Briggs and the S/G does not spin engine over as fast as a gear start that I have, but is does start. 1977 engine from a Yazzo mower that has seen only a head change as original one was cracked and a points and condenser. Also I have looked and felt for that bump on the cam and and came up zilch. If that had the so called bump, the engine would not rock back and forth when brought to a stop.
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Bob, the so called "bump" is not very noticeable. I filed the one off my 10 Hp 243431 many years ago to give it torque at very low speeds when pulling, since it had also been converted to battery ignition. The bulge on the cam lobe is very gradual and only a little more than the valve clearance so that it opens the valve a little at cranking speeds. You have to look very closely to even see the bulge on the cam lobe. I started by examining a cam from a 3 Hp push mower before I went into the larger engine and removed the bump. Believe me, it does make the engine harder to turn over. Mine likes to spin the belt when the battery is fully charged. In fact, I have rolled the engine backward by hand to allow it to pick up speed before hitting compression. Too much valve clearance will also stop the compression release bump from doing its job.
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Since the extra lobe is made in with the intake side of a Briggs it requirs the intake to be at exsact spec for it operate properly. IF I recall it's .008 on the intake and .010 for the valve lash. If the engine is worn it's possible for the intake valve to drop a little in the seat. This will close the gap to near not sealing and require someone to service the valves. If the person doing this sets both at .020 or simply grinds too much off the intake valve then they effectively remove the decompresion release causing very hard starts. The size of the cyl. and the displacement of the 16's they really need a gear starter anyway. If you can find one or ad this you'll be pleased as it gives a FDT a nice clean line without the bulky gen. on that side of the engine.
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Hi Dave, I happen to have one, but it is in my 7016h that is next in line to get running. May have to figure out how to get the larger amperage car battery strapped in the 3212v.... So, the valves on these are not particularly adjustable, at least not with a set screw or shim? The valves have to be physically ground or material added to the shaft? Appreciate the replies. Rick
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B/S valves are not adjustable. They must be filed/ground to provide proper clearance. I recently did this on my 713S. The exhaust had no clearance and after about 15 minutes of operation it would act like the carb needed adjusting. All you need to do is pull off the crankcase vent cover to get to the valves. I just inserted a flat file between the valve and cam follower and removed enough material to give the correct clearance. I wiped out all the metal particles I could get, then sprayed the area with PB blast to remove any remaining. Then I put the cover back on. It was about a 15 minute operation to complete the task. The engine has not acted up on me since.
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