18 hp briggs and stratton smoking

[LW1911]

On mine crankcase was over full with oil/gas mix and pumped out breather tube

[snackmaster]

I understand the needle/seat/float issue with the gas, i don't understand what is drawing oil up into the air filter housing thru the breather tube. Bad rings? too much oil? if i read it right, the TM calls for 48oz. i don't mind not knowing, i get to tear stuff apart and see inside

[LW1911]

Probably already checked this but, had a 16hp vanguard in a mower acting like yours, float needle was not seating right letting fuel dump into cylinders

[snackmaster]

See what i mean? lol...sometimes i get a mix of oil with gas in it up thru the black rubber tube that comes up into the cleaner housing. There's a brass tube that comes up from between the heads next to the carb, 1/2" diam. rubber tube feeds from that, up into air filter housing. makes sense that you wouldn't vent the crankcase that way(if at all)...

[onefunzr2]

Reading thru this post, I realize how little i know about small engines. i'm having same problems with my 18h B&S Vanguard. I have very little "go" on throttle, the white smoke, oil / fuel mix from PCV into air cleaner housing.

The 18 horse Briggs Vanguard in my Max II is a 4 stroke V twin and (1) doesn't use a PCV valve or (2) oil/fuel mix. The only thing I've ever added to the 87 octane no-ethanol gasoline is Seafoam SF-16 motor treatment. Gobs of white smoke came out the exhaust when I dumped a little down the carb throat. But it now purrs like the proverbial 'kitten' with no more surging.

[snackmaster]

Reading thru this post, I realize how little i know about small engines. i'm having same problems with my 18h B&S Vanguard. I have very little "go" on throttle, the white smoke, oil / fuel mix from PCV into air cleaner housing. Someone suggested bad rings, i dunno...

[Trapper Dano]

If the valve is going back into the same head you should be ok. If it were mine I would spend the extra time and lap them end make sure the have a good seal.

Thanks I think I might just invest in the tool and the compound.

I notice in the pics it looks like only one valve has a stem seal. Shouldn't both valves have a stem seal?

Also are you using a compression tester that somehow allows the sparkplug to remain functional so that you are measuring combustion pressure rather than just raw compression pressure. Not sure any such tool exists but I am grasping at straws trying to explain your readings.

Both heads are identical, the intake and exhaust match up on both sides. And the compression was done plugs out.

Assuming the compression release is the difference in compression, and assuming the compression reading is high, does the machine have the carbon or steel head gaskets in it? Are they both the same? Is this by chance a Bandolero?

Just grasping at straws, I need to reread this post again.

It has the carbon gaskets in it. Would it be possible to have high compression in only the one cylinder if the compression relief failed?

Its a little late now but i would have unhooked the rocker arms and put the piston on the bad cyl to the bottom of the bore and put a 120lbs in the cyl from a air compressor.

if there's a leak you would of heard it, easy to track it down...

Might come to that yet, not making any head way yet.

[Nubs]

Its a little late now but i would have unhooked the rocker arms and put the piston on the bad cyl to the bottom of the bore and put a 120lbs in the cyl from a air compressor.

if there's a leak you would of heard it, easy to track it down...

[ARGOJIM]

Assuming the compression release is the difference in compression, and assuming the compression reading is high, does the machine have the carbon or steel head gaskets in it? Are they both the same? Is this by chance a Bandolero?

Just grasping at straws, I need to reread this post again.

[dirtdobber]

I notice in the pics it looks like only one valve has a stem seal. Shouldn't both valves have a stem seal?

Also are you using a compression tester that somehow allows the sparkplug to remain functional so that you are measuring combustion pressure rather than just raw compression pressure. Not sure any such tool exists but I am grasping at straws trying to explain your readings.

[Dixon]

If the valve is going back into the same head you should be ok. If it were mine I would spend the extra time and lap them end make sure the have a good seal.

[Trapper Dano]

[ATTACH=CONFIG]16178[/ATTACH][ATTACH=CONFIG]16179[/ATTACH][ATTACH=CONFIG]16180[/ATTACH][ATTACH=CONFIG]16178[/ATTACH][ATTACH=CONFIG]16179[/ATTACH][ATTACH=CONFIG]16180[/ATTACH]

Just got home and pulled the other valve cover to compare valve seals, both heads look identical. I guess I might as well pull the head off that side to just to make sure it and the piston and are good and clean them up before I put them back together. If I pull the keepers and take the valves out and clean them while they are off, will I need to re Lap them, or can I just put them back in?

[Trapper Dano]

Stupid question did you have spark in both cylinders at the tester and the plug? a dead plug or burnt diode will cause poor performance and rough running.

Perhaps Nubs knows the rough compression readings.

Yeah Jim i have spark in both, even put brand new plugs in it.

[ARGOJIM]

Stupid question did you have spark in both cylinders at the tester and the plug? a dead plug or burnt diode will cause poor performance and rough running.

Perhaps Nubs knows the rough compression readings.

[Trapper Dano]

I thought the same thing that it was too high and had no clue how it could get that high. I retested both cylinders 5 times always got the same readings 90 in front and just shy of 170 in the rear cylinder. I too am baffled. I know very little about small engines but I think the head looks normal, doesn't look like any of the other ones I had been able to look up with head problems. The gasket is good, and I am able to hand compress both the springs and both valves open?