# i need help on 12 hp briggs synchro balance engine



## CHUY68 (Aug 20, 2008)

hi guys . i have a 12 hp synchro balanced model 281707 type 0411 briggs . engine starts right up but the whole engine vibrates like crazy , i unbolted the engine off the riding mower frame and took the pan off . i could see the side of the outer counterweight was rubbing on the side of the crankshaft gear . counter weight has a lot of movement toward the flywheel and the bottom pulleys, there is a miniature conn. rod look alike holding the weights and at the end of the rod there is nothing holding it thats where the weight movement is coming from , is there suppose to be a bolt there? at the other end of the rod there is a long bolt that thru from the outer - rod-and inner weight. but no bolt at the other end of the weight rod. i went to the part list on www.briggs & stratton and it does not show a bolt there.


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## paulr44 (Oct 14, 2008)

I couldn't find an exact pic of your model & type engine, but perhaps this will help:
http://www.tpub.com/content/recoveryvehicles/TM-5-4240-501-14P/css/TM-5-4240-501-14P_264.htm


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## CHUY68 (Aug 20, 2008)

thanks paulr44 , on the illustrations you sent me they dont show a bolt holding the other end of the counterweight link. i probably just need the whole counterweight assembly since they are showing some wear where the weight rubs on crankshaft. where is a good place to buy this parts? anybody out here got a counterweight assembly for sale???
thanks for your time


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## 30yearTech (Sep 14, 2006)

If there is wear on the counter weights, there probably is also wear on the crankshaft bearings that operate the weights. This may not be a cost effective repair for your engine.

You can order parts from many sources on line, just do a search for Briggs and Stratton parts.

You can look at an illustrated parts list for your engine here:
http://www.briggsandstratton.com/ma...e=Illustrated Parts Lists&menu=nav3&subMenu=3

Just use your model number and the first 4 digits of your type number to locate your engine.


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## CHUY68 (Aug 20, 2008)

Hi Guys , Thank You For Your Time On Answering My Question , Im Wondering If I Take The Whole Counterweight Assembly Completely Off The Engine, And Run It Without It. What Do You Think? There Is Wear To Where The Counterweghts Hangs On The Cranckshaft, (maybe The Bearings U R Talking About 30yeartech.)


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## 30yearTech (Sep 14, 2006)

I have never run a syncro balanced engine without the counter weights. I suspect it will vibrate about as bad as with the weights in their current condition. You will however not have to worry about the weights slinging loose and blowing the bottom of your engine out!


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## paulr44 (Oct 14, 2008)

I've seen Kohler M16's run without the balance gears - not terrible but noticeable. Never ran a briggs without it..
Paul


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