OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Engines Questions On Briggs & Stratton Engines Briggs 550EX Ready Start No Prime No Choke

Hi Guys,

Just after some thoughts on mower I picked up a couple of weeks ago. It�s a fairly new Ready Start no prime no choke Briggs Engine that�s done very little work.

I have given the motor a standard once over including:

- Clean the carb
- New plug
- New air filter
- Valve clearance checked and considered sufficient. .15mm inlet & .20mm exhaust.

The linkages appear to be all hooked up correctly. When the engine is cold the choke is closed and then it appears to open up as it should once warm.

I�ll try to describe the problem as best as possible:

- The mower starts very easily � If not first pull its usually second.
- The mower runs really nicely for about 20 odd seconds and then it starts to smoke quite bad. It is white smoke.
- Drops of oil start coming out of the exhaust and landing on the base.
- Despite the engine smoking it actually runs quite smoothly.

Let the engine cool and then restart, it will do the same thing. It runs cleanly for about 20 seconds and then it starts to smoke quite badly. The engine again still runs quite smooth.

Thoughts:

1) PCV Valve faulty/ blocked _ I�ll be honest I haven�t looked at the pcv setup on these newer engines yet
2) Possible cracked oil/ scraper ring � I sure hope I am wrong
3) Possibility of something being wrong with the no prime no choke system

Considering the age of the engine I am hoping I have just missed something specific to these newer style engines.

Sorry I don�t have the model type and code at the moment however I will get it tonight. Apologies for the photo with my daughters head. She is always trying to hijack my photos.

Thanks

Jaffa

Hi Jaffa J,

Have you tried running the engine without the air filter to see if it does the same thing?

Yes I tried to run the engine with no air filter and it made no difference.

Any suggestions always welcome.

Any other suggestions would be appreciated.

Jaffa, have you checked the oil level, if drops of oil start dripping from the exhaust oil is being carried over, only a couple of places that can get by,too much oil so the rings can't cope, oil ring not sealing/broken or through the valve guides

Done a little more thinking and it giving all the symptoms of a blown head gasket between the combustion chamber and the pushrod galley. This seems like a fairly common problem just not one I have encountered to date. Most of my work has been on the side valve engines.

Thoughts before I get in and tear it apart?

Yes it sounds like it is a head gasket. The other thing to check would be the breather. From memory the flywheel has to come off to get to it.