I had this question buried in the body of my smoking post. Really need to know if 110-115 reading on compression test is good or bad for a briggs 18.5 HP single cylinder engine. Thanks 'MO

It should run with that compression reading.

It should run with that compression reading.

It runs like a bandit!!!! Starts so fast its scary. Just smokes a lot. I thought the compression might be to low causing a lot of blow by. Since I don't have the equip. for a leak down test, I used a regular compression tester on it. funny thing is, it don't start smoking till it warms up some. Thing looks like a mosquito fogging machine!!!

Try changing the oil, the oil in it now may be to thin or may contain moisture or gas. What color is the smoke? If its black or blue most likely its burning oil. white smoke sounds like moisture somewhere is the system.

sounds like the crank case breather might be bad , pull the tube off that goes to the filter housing and look at it see if it has oil in it . also could be a head gasket .

Your compression reading is a little low, but I would not think enough to fog like you describe. Possibly a leaking head gasket may be the culprit.

sounds like the crank case breather might be bad , pull the tube off that goes to the filter housing and look at it see if it has oil in it . also could be a head gasket .


+1 - scrench & 30yearTech... May even be a crack in the case due to smoking after warm.

Your compression reading is a little low, but I would not think enough to fog like you describe. Possibly a leaking head gasket may be the culprit.
You hit the nail on the head!!!! Or I should say, the leak on the head!!! The head gasket was leaking between the cylinder and the "galley" where the push rods go back into the case. Got it all back together with new gaskets and NO smoke!!!! So, I basically have a mower with only 27 hours on it for the price of a gasket kit and some of my labor!! Does it get any better???????? Thanks for everyones input on this problem. 'Mo :wave: