Some more questions/ Call for opinions

[GWGAllisfan 159]

I was tinkering with my B-10 this weekend and noticed that when I turned the crank by hand the 12 HP Briggs seemed to let all the compression release as it went past TDC. Also when turning with the starter there is a loud “Chuff” as the engine turns over. When it fires, which is rarely, there is a loud metallic “Clang” I would assume this means either head gasket or valves are questionable? I bought a head gasket, thought I’d try to change it, however wasn’t sure if the shroud would move enough to let the head come off with the engine in the tractor. It looks like most of the tin can stay on during this procedure but, having never done it before, I’m not sure? I figure that when the head is off a bad valve will be visible as well. I am already aware that each head bolt has to go in the proper hole, but am looking for any other tips or tricks. Again forgive me for the endless Briggs questions. I’d probably have given up long ago if not for this Site

[D-17_Dave 12]

Your on the right track. Remove the starter/gen. brackets and loosen the lower pivot bolts and remove the belt to let the S/G drop to the side. Then you can slide the top schroud off w/ the head. TDC on the fireing stroke will rest the valves so they don't hit the head, but this shouldn't really interfear.

[GWGAllisfan 159]

thanks. I think I bought the wrong gasket, though. When I got home i laid it over the bolt heads and it doesn't line up. I bought the one the parts books said were the the one for a 12, 14 or 16. (692231)replacing (270662) I guess this is a 10 using (692230) I can't tell because there is no id stamped or tagged on the motour.

[Tacey 0]

Regarding the "Chuff" sound; I would guess that is designed into the engine. I think that is called "Easy Spin" by Briggs (?). It allows the engine to crank over easier during the start-up phase. The "Clang" I can't help you with. Wild guess--- built up carbon on the piston. Anyone else? Tacey

[Chris727 1,925]

Hi, if you want to know whether it is a 10 or a larger engine post a pic and I can tell you. The 12 is somewhat different. There are some subtle differences in appearance between all models, but they are hard to describe. All the cast briggs bigger than 12hp through 16hp are synchro-balaced, may be part of you noise, or maybe its partially firing? You say it rarely fires, so if you have spark issues those will need to be resovled before it will run right, you could just convert it to a battery ignition using an automotive coil. You might want to look the engine over again for numbers, there will be numbers stamped somewhere. They have been located in four places. First they were located on a metal ID tag on the front of the cylinder, on the part behind the grill, then they began stamping the numbers onto the blower cover. This is on the side where the carb is located, just down to the right of it. Some engines have these numbers stamped on the blower cover on the opposite side of the tractor where the generator is. It would be to your left and down a little from the generator. Lastly on the newer briggs's (late 70's they were stamping the numbers up at the top of the engine on the blower over, basically right by the head. If your engine came with an original blower cover then there should be #'s somewhere.

[GWGAllisfan 159]

I'll look again for a model number. All I found was a tag that said made to Allis chalmers specifications. I'll get the other gasket so whichever I need I'll have it ready.

[Wishin2BMowin 0]

Things to check for when the head is off are.. Look at the cylinder head surface where the gasket seals for any cracks or pits in the metal. If you have any the new gasket won't last long before it leaks again. I found this out the hard way and needed to by a used head and do the job over again. Check the cylinder where the gasket seals as well to make sure it's clean and flat. If anyone ever over-tighted the head bolts the threaded holes in the cylinder can have a slight bump on them. A flat file can clean that surface well. Make sure the head bolts are clean and oiled before re-assembly and don't over tighten them. Best of luck...