B&S 14HP Vanguard Problems

[wheely_boy]

I guess this is what you get when you gloat about your 7 year old, flawlessly performing machine. I serviced the motor yesterday, new oil, oil filter, air filter, spark plug. I'm cutting the grass this morning and about 1 hr. into it, I smelled something hot. I figured I burning off some spilled oil. A couple of minutes later, the engine popped and engulfed me into a humungous cloud of smoke. I shut it down, and noticed that the motor was HOT. I checked it over and noticed the oil was a bit high. I drained it off and the oil was so hot, it was boiling as it came out. I refreshed the oil, let it cool down some and she fired right up, except now it smokes.
Did I cook something in the engine or is it going to stop smoking at some point? Any suggestions about possible scenarios would be appreciated before I start any major surgury.
Now my neighbors hoodless Sabre don't look so bad.

[chipmaker]

I assume you did use the proper oil, and filled it correctly. Is the filter an after market type? If after market type are you sure it was really a correct interchange?

It seems hard to believe even with improper oil unless it was 5wt or something like that the motor would overheat from lack of lub.......and even with 5 or 10 wt odds are it would just start smoking pretty bad as it got warmed up. Filter could have been clogged,or perhaps too high a relief valve in it if after market type.....

[jodyand]

You may have blown a head gasket or maybe your crankcase vent is plugged.

[Durwood]

I'm not a mechanic Wheely, but it sounds like the same thing that happened to my old snapper. The valve seat has let loose. I took mine to a napa store and they drilled it out so a car valve seat would work because i couldn't get the right size anymore for my motor. I bet that is what has happened.
The engine might have gotten hot from air fins plugged with grass to cause it. The hot engine probably caused the seat to let go.


Durwood

[modre]

>noticed the oil was a bit high.<

smell the oil and see if it smells like gas. oil may expand a bit when hot, but it doesn't mysteriously increase the level to "a bit high".

if so, possible gas contaminated oil compromised the lubrication...quick fix is put an inline shut-off valve on the fuel line and manually stop all gas availability to carb when tractor's not in use. gas in the oil is a potentially dangerous situation. the right fix would be take the carb apart and check for dirt under the seat or wear on the valve tip...replace if necessary... and make sure the float level is set to spec.

you might pull the shroud off to see if a mouse built a nest blocking the cooling fins...also check to see if the engine is covered in oil from a leak which could also attract/collect enough dirt on the fins to compromise cooling.

if none of those, and you just overfilled the crankcase, (and it's a pumped lube system), the trouble with high oil level is if the crank throws contacts the surface of the oil and whips air into it...called "frothing"...then the pump picks up 1/2 air 1/2 oil and the delivery is compromised.

the other things that can cause heat (tho maybe not likely in this case) is ignition too advanced or a lean carb setting.

I suspect blocked cooling fins, but the high oil level says gas leaking in...if it's gas, get it out and refill fresh.

[modre]

the valve seat suggestion was also good...a compression check would tell you it that's the case.

[wheely_boy]

http://img.photobucket.com/albums/v187/wheely_boy/tractors/MVC-049S.jpg
http://img.photobucket.com/albums/v187/wheely_boy/tractors/MVC-048S.jpg
http://img.photobucket.com/albums/v187/wheely_boy/tractors/MVC-047S.jpg
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Well it only took about a half an hour to get to this point. The guy at the dealer was pretty convinced that the head gasket was toast. A new one will cost about $10. I appreciate any other opinions. What is the best way to clean the crud off of the cylinder top and the valves?

[jodyand]

To get the crap off i would use a Scott's bright pad and some carb cleaner. So it was the head gasket that went bad?

[wheely_boy]

I don't think I'll know for sure until I install the new head gasket. If it still smokes, then we move on to the rings.

[MowHoward2210]

While your at it, check for any warp-age on the head with a straight edge rule or anything that might give you a visual of any warp-age. Also if it's aluminum, be careful not to score it when cleaning.

[wheely_boy]

I got it back together again with the new head gasket. It runs OK without smoking. After an hour of mowing yesterday, I noticed it was surging a bit at WOT, but ran good at idle. I haven't replaced the oil filter yet, and I am wondering if it is possible that it was defective causing my problem in the first place. I also did not adjust the valves when I slapped her back together and I don't have enough experience to know what the symtoms of badly adjusted valves are. Any advice would be appreciated.

[cadurning]

Wheely,

By all means adjust the valves before running again. A too tight setting can allow the valves to burn and too loose will beat up the valve train. In looking at the top of the piston it looks like you have been getting oil past the rings(the clean areas). If it runs fine and doesn't use too much oil, I would forget about the rings until a later date.