Briggs&Stratton Powerbuilt 3130, 344cc, Low power

[Per_XXX]

Clean the inside of the crankcase but most of the metal shavings will be in the oil pan be sure and clean it good.

A lot of "grey stuff" in the oil pan. I suppose that was the remaings of the cam lobe.....

 

[Tiger Small Engine]

Some feeedback. You were right.
Its a miracle that it worked at all. Almost round.

But what surprised me was that it looked as if the engine had ben opened before. I thought this engine was "sealed for life". I do of course not know what was done but i must have been for a good purpose. Are camshafts typical weak components?

Talk about worn camshaft lobes! That is ridiculous. As you said, how did the engine even run?

 

[slomo]

It's a Briggs guys. Some don't even require gasoline LOL.

 

[FireFeliks]

Hi

from one day to next day, the power was dramatically reduced. Something broken i guess, not just getting "old".
I have checked the spring on the governer and the valve clearance without result.

But when looking at how the valves move when turning the engine I might have something.
The upper valve (exhaust i guess) move as expected.
The lower valve moves less and has a "dubble jump.

Damaged camshaft?

Any ideas or suggestion what to check?

That double jump on the lower valve is a classic sign of a sticking valve or a worn cam lobe. Given the sudden power loss, I'd bet on a valve not sealing. Check your lash and look for carbon buildup. This guide explains how valve issues cause power loss: https://wildwoodsmallenginerepair.com/small-engine-valve-adjustment/

 

[Per_XXX]

That double jump on the lower valve is a classic sign of a sticking valve or a worn cam lobe. Given the sudden power loss, I'd bet on a valve not sealing. Check your lash and look for carbon buildup. This guide explains how valve issues cause power loss: https://wildwoodsmallenginerepair.com/small-engine-valve-adjustment/

Before I adjusted the lash, it was slightly to big. Then I reduced it a bit, but no big difference in result.
Both cam lobes in poor condition, The inlet REAL bad!!!
Now I have ordered a new camshat and will also replace the tappets.

Lets hope the valves themselves are not bad.

 

[slomo]

Before I adjusted the lash, it was slightly to big. Then I reduced it a bit, but no big difference in result.
Both cam lobes in poor condition, The inlet REAL bad!!!
Now I have ordered a new camshat and will also replace the tappets.

Lets hope the valves themselves are not bad.

Make sure you de-carbon the entire block when you have her laid open on the table.

Valves will need lapping as well as the head and area on the block where the head sits.

 

[Auto Doc's]

Even if you clean the inside of the case and sump very well, run it for 15 minutes and change the oil again. On the second change if you still see glitter in the oil, change it again until you have very clean oil. (Use cheap oil until you run it a few hours for break-in.)

If this glitter is left in the engine, it will just grind away at the moving components until another failure happens.