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Here's an easy one..


LJFarraher

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Hiya all again.. Well..got a chance to rebuild/upgrade my 5212.5H Simplicity. I have the Briggs I/C twin 12.5hp motor. I found on an auction..a 18 hp (I think a 19 actually) briggs opposed I/C twin that seems to only need an exhaust valve guide seat installed. My briggs is the following model.. 404707 type 0122-01 The 18 is.. 42A707 type 1237-01 Both verticals of course.. Now..will the 42A fit with all hardware (muffler and cable) right in?? Or will I need to rig new cables and wiring? Also..would it be worth it for the other motor (so far the bids at $10.50)..rebuilding it with new rings and valve seats (since the one exaust seat came out). Or should I not try increasing the HP in this tractor? I know the Hydro and such should handle it.. What would YOU do in my shoes if the 12.5 was getting tired?? Thanks for input all.... Lou.
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louis check this link out, it is to Small engine warehouse (one of our sponsors) they have a special going on now for the same 12.5 hp ic briggs think its 375 with free shipping and a 2yr warranty. depending on what that twin briggs goes for at auction this may be a good option considering it is prob a direct bolt on and brandie new. here is the link [url][/url]http://www.smallenginewarehouse.com/product.asp?PN=28V707 good luck john
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Go to the Briggs website and download both parts books and compare. Your talking a 2 CID bigger engine. Most likely you can swap parts. You can also see if they both have the same crankshaft.
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Lou, the engine John is speaking of is the 12.5 horsepower single cylinder engine(28V707). The price is very good, and it will work in your tractor. The only thing I know you will need is the proper muffler. It has the "choke-a-matic" throttle control, which means that the choke comes on only with the throttle lever, when you move the control above the high speed position. To change that to the choke system that your tractor now uses, you have to change the choke shaft. Since I am not familiar with the fuel tank location on your tractor, you MAY have to add a fuel pump. The twin cylinder has a pump that is integral with the carb, but the carb sits much higher on that engine. As to replacing your 12.5 with the 18 or 19 horse engine, it should be a bolt in job. Everything should fit. The tractor will handle the extra power. From the cost standpoint, it may be cheaper just to rebuild your 12.5. Depending on how long the other engine was run with a loose valve seat, your options will range from reinstalling the original seat and peening it in place, to having the block machined and a universal seat installed. Pat
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WOW.. You guys really filled me with input in a hurry here.. I have noticed the 12.5 single from there from time to time... That is one option..(and a good one too..thanks..) As for the rebuild..been thinking about that as I found that the seat has been out for a short time..There would be more to it than to a quick seat fix..So it is now becoming somewhat more costly than the other two options. So Pat...your right about the extra machining.. Well..are those opposed twins good enought to keep and rebuild?? Or should I go to the 12.5 or 13 hp single option? As for pump..I would have to see how far above the tank sits compared to the single.. I heard the opposed twins were good..But makes me wonder why briggs dropped the line?? Lou
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Lou, there are better engines, but the opposed twin is about as good as any in it's class. It has been discontinued for the same reason that other L-heads have been or are being discontinued. They can't meet the emissions regulations without a lot of expense. OHV engines can run at higher compression. That means more power with less displacement, and more efficient burning of fuel. Not sure, but I would imagine that the single cylinder 12.5 horse would be a little more efficient, as it is a 28 cu. in. engine. The 12.5 twin is a 40 cubic inch engine. Leroy, don't know about a wealth of information, maybe just a small fortune combined with a lot of B.S. Pat
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