Husqvarna 125BVX Leaf Blower quits after 30-60 seconds.

[chainsawdave]

This is the same Blower that I solved the No Spark problem on back in October 2019.

I was given for free this Husqvarna 125BVX handheld blower that defies almost every fix I can think of. Failure symptom is it runs for 30-60 seconds after priming via bulb, then it quits unless i periodically pump the bulb--all this while on either half or full choke. I have installed all new fuel lines, bulb, filter, carb and tested with fuel tank cap off/open. Fuel lines are transparent type so i can see fuel is not flowing to the carb. I have adjusted coil to flywheel gap so it gets a strong spark. I don't have a compression tester--the auto parts store i usually borrow from isn't loaning due to Coronavirus. I strongly suspect the Crankcase Seals are bad, especially the one opposite from Recoil Starter side (see 2nd and 4th photos). The Crankcase Seal on the Recoil Starter side looks OK, but I will replace that as well. Cylinder walls are not scored, but piston shows some blowby. I figure as long as i am ordering new Seals for another $22-25 i will replace cylinder and piston and rings. Should be less than $50 to fix this blower which was given to me for free.

A couple questions: 1) does the blowby/carbon on side of piston look normal? Unfortunately I have no idea how many hours this blower was used. 2) do you think i am on the right track replacing Crankshaft Seals (as well as piston and rings and cylinder)? Gonna have a practically new machine!

Thanks in advance for any input.

 

[wmazz]

It is too bad that you didn't take a picture of the main bearings without
the main seal. A common sign of a main seal leaking on the vacuum
side of the seal is a dirty main bearing.

Other signs of problems during disassembly are wet gaskets. Of course
a pressure / vacuum test would have determined the main seal condition
too.

There are other things that you need to look for when you disassemble
the carb. If you still have the parts, I can show you what to look for.

By the description of the problem, the float chamber is filling up, and
then the needle and seat remains closed, and the carb runs out of gas.

Many people may blame the fuel pump, but it is more common that
a vacuum leak (possibly a pressure leak too) is the problem.


Bill M.

 

[chainsawdave]

Bill, thanks for the input. In the past week or two I watched many/most of the Joe Pace videos on Youtube and now understand that without a Pressure/Vacuum Tester I am "driving in the dark" to fix this blower. I plan to buy a MityVac so that I can diagnose this properly --but it might be a month or two until I get around to that. I will update this thread when I get moving on this project again. I appreciate the idea/observation that needle and seat are probably remaining Closed (this seams to happen with both the original and replacement carb ) so I need to look elsewhere for what is causing this condition. Thanks again.

Dave