Bolens w/Twin 16 Briggs has *serious* blow-by

[6Mickey]

My horizontal shafted Briggs Twin 16 has extreme blow by. Hard to keep oil in it.
Starts easily, winter and even better in summer.
Reasonable power.
Compression just over 100 psia (cold), both sides.

Does it have valve guide seals that I can replace?

Do valve guides wear severely enough to cause this in this model of Briggs?

Do the 'breathers' stick or fail over time?

The breathers is what I am after next.

Anyone have suggestions or ideas what to look for to remedy this? I feel with that level of compression, the rings probably are not bad enough to cause this amount of blow-by.

Thanks, in advance, for you response!

mlk a.k.a. 6Mickey

 

[greggn]

Have you switched to 30 weight oil for the summer months?

 

[Walt 2002]

Well you didn't post the model number so I don't know if it has one or two breathers. Typically, a horizontal shaft horizontally opposed twin B&S uses two breathers. You can check the breather by disconnecting the hose from the air cleaner box, you should be able to reach it but if not, attach an auxiliary hose. Suck and blow on each hose, one at a time. You should be able to suck easily but should quickly switch over to restricted when blowing. IF you take the breather out, do not press on the fiber disk inside or you will damage the valve. A 16 hp horizontally opposed twin could have an aluminum cylinder bore which do not wear as well as a sleeved cylinder. IF it actually has the compression you state, that should not be the case.

Walt Conner