Old B&S engine won't start

[judge2b]

I have a Briggs and Stratton engine that won't start, model 170402, type 1015-01, code 74032510

Basically it won't start. Fuel is not getting into the engine. I pulled the plug and the valve inside opens and closes but no fuel enters the chamber when I pull start.

I have cleaned out the fuel tank, put fresh fuel in, thoroughly cleaned the fuel bowl/valve assembly, replaced the mesh filter in the bowl, replaced the bowl gasket. I also made sure air can get into the fuel tank via the small hole in the tank cap. There is no fuel filter on the line, only the filter in the bowl.
I have replaced the fuel line.
I have completely taken apart the carb and swapped out all the parts in the carb rebuild kit so all the gaskets and springs and such are new. I also thoroughly cleaned out ever single orifice in the carb. The air cleaner isn't spotless, but its decently clean and there's no gunk in any of the airways going to the carb or the engine body.
I changed the oil and replaced the spark plug. When I attempt to pull start the engine I do get consistent sparks from the plug.
I also cleaned out the breather assembly as well.

Any ideas? I've attached the parts manual as well. Some of the parts don't apply since this is one of the older models obviously.

 

[Rivets]

Going to ask, what may be seem like dumb questions. Sorry but I'm a visual guy. 1. Have you removed the plug and looked to see that both valves are opening and closing? 2. Have you put your hand over the air horn and turned engine engine over, to verify that you have suction, drawing air through the carb? 3. Have you tried to start the engine by adding fuel or carb cleaner directly into the cylinder? 4. Have you checked to verify that you have fuel in the carb bowl and the float level is set correctly? Here is a service manual which may also help.

http://dl.dropbox.com/u/12502267/B&S Service Manuals/01_270962SingleCylinderLHead.pdf

 

[EngineMan]

I would do a compression test.

 

[judge2b]

1. Have you removed the plug and looked to see that both valves are opening and closing?
When I remove the plug a see 1 valve that's a flap that opens by moving up toward the plug and closes by going back down. There is another valve that looks more like a piston moving up and down inside of a cylinder. I can see it when it rises to to the top of the hole and then it disappears when it sinks down in the hole. There are not 2 valves that look the same though.

2. Have you put your hand over the air horn and turned engine engine over, to verify that you have suction, drawing air through the carb?
Yes

3. Have you tried to start the engine by adding fuel or carb cleaner directly into the cylinder?
I did try with carb cleaner, didn't start

4. Have you checked to verify that you have fuel in the carb bowl and the float level is set correctly?
I manually added fuel to the carb because fuel was not being pulled through the fuel line. That is the only fuel in the carb bowl. As far as the float level being set correctly, how do I adjust the float level?

 

[judge2b]

I just found some sediment that had collected on the mesh filter above the fuel sediment bowl that wasn't there before. Now I have free flowing fuel to the carb but still not seeing fuel in the chamber when I pull the plug. Also tried to start with carb cleaner in the chamber again: nothing.

 

[Rivets]

In the manual I posted it will show you how to adjust the float.

 

[judge2b]

I would do a compression test.

Ok, dry compression test shows it holding at 51 psi. 9 minutes later it was still at 50 psi. I couldn't find a pressure value in that repair manual because it calls for using some special B&S gauges with color codes or something...

 

[Rivets]

How did you do your compression test. Did you: install tester------turn the engine over through at least 4 complete cycles------take a reading and repeat a second time. Doing it only once does not give an accurate reading. If the reading comes up low, you should repeat the test with a small amount of oil to see if the reading go up. It they do, it is an indication of bad rings. There is no set compression spec for most engines, due to the compression release mechanism. What I look for is a reading of about 90 what testing with a recoil starter and 110 with an electric starter.

 

[judge2b]

How did you do your compression test. Did you: install tester------turn the engine over through at least 4 complete cycles------take a reading and repeat a second time. Doing it only once does not give an accurate reading. If the reading comes up low, you should repeat the test with a small amount of oil to see if the reading go up. It they do, it is an indication of bad rings. There is no set compression spec for most engines, due to the compression release mechanism. What I look for is a reading of about 90 what testing with a recoil starter and 110 with an electric starter.

Yes I installed the tester, turned the engine over 5 or 6 times, did this at least 2 times, maybe 3 (same reading each time). I didn't try the wet test though, I'll do that.

Also, I did adjust the float so that's set correctly now.

 

[Buckshot 1]

:smile: That being a up draft carb. Check for warping between the the two carb halves. Also check for air leaks around the mounting gaskets. Did you install the gasket between the two carb halves correctly? Instead of a comp test, I would do a leak down test.