Briggs 128T02-0118-B1 on John Deere low compression?

[gdrepairs69]

Here I have a Briggs 128T02-0118-B1 on a John Deere a guy brougth me a month ago with a starting problem, the mower is only 2 years old. I got it started by using some starter fluid and would run on it and start so I basically removed the carb and put in a needle and set and cleaned up the carb and put it back on. It would then start and run for a couple second then on the next pull it would start again wallop down and then back up to operation rpms and steady up. At this point he was happy with it. He used it 2 times and now were back to square one and will only start again with starter fluid. I did a basic compression test and it was only 30. Here i have removed the head to see what we have. The black ring of carbon on the cylinder wall? What doe's this tell maybe about the problem? Any help would be great!
:confused2:

 

[sonnydays40]

Re: Briggs on John Deere low compression?

Let me repeat a post from another thread that might just get you the help you need. Please follow it.


Since this is a help forum, it is only fair that the people trying to answer questions have some information to work with, so they can give an accurate answer. This helps them if they need to research parts or service information on your engine or equipment. In the first part of your post please include your engine numbers from the ID tag or stamping and the equipment type and model numbers that are on it. Failure to do this may result in you not receiving any accurate help with your problem.

Many of the tech's that hang out here work in or have there own shops and the first thing they do when they make up a work order on a unit is include the engine and equipment numbers on the work order. Since this technical forum is offered free to the public, it's the least we can ask you to do, so please help all of us out. *So please post the numbers in the new topic you start to ask your question. It should be the first thing you write before beginning your question.

 

[EngineMan]

It needs a new head gasket its been blowing on the right hand side, replace it and then do other compression test. there is also a little oil burning, but all B&S burn a little.

 

[treeman]

It needs a new head gasket its been blowing on the right hand side, replace it and then do other compression test. there is also a little oil burning, but all B&S burn a little.

I agree....

 

[gdrepairs69]

Yes thank you for your replies. Now I see your right.:thumbsup:

 

[gdrepairs69]

I replaced the head gasket and now only have about 40 for compression? This seems lows to me so what is a minimum range here to operate properly?:confused2:

 

[EngineMan]

Did you lap the valves..?

 

[chance123]

That black ring you saw in the upper part of the cylinder, is the portion of the cylinder that the rings "do not" contact the cylinder. If you run your finger up & down the cylinder over that black ring, you will no doubt feel a ridge. Some of this ridge is carbon, but most of it will be the difference between when the cylinder was new and how much it has worn. A little is a lot because your rings must have a small gap to seal your compression

 

[redice]

The piston rings are probably burned up. The newer engines do that more often. You will need to take the whole piston out and change them. Don't do it unless your certain thats the problem.