Help me fix my leaf blower!!

So I have a STIHL br420



Its about 8 years old and has seen a lot of heavy use. earlier in the season I tried to start it up and could only get it to start for 2-10 seconds then it would choke its self out. either not enough air or fuel its hard to tell.

it had pretty low compression judging by the pull start and finger over the spark plug hole test. So I installed brand new piston/rings/cylinder head and a new carburetor.. honestly just because it was so old and figured it could use it. well the problem didn't go away, damn!

I know its getting spark because it starts for a couple seconds. maybe the coil is the problem? there is almost nothing to these 2-stroke engines so I am running out of ideas. I have tried adjusting the carburetor and it doesn't seem to affect the machine in anyway.

what should I check next?

 

how old is the gas? even though you replaced the carb, bad gas can gum up a new carb pretty quick.

 

I use their chainsaws a lot for work and if I don't clean out the spark arrester/muffler it will choke it down and run terribly. Needs to be able to push out air efficiently as well.

Try taking off the muffler and start it. If it stays running then you found the problem

 

This. My Husky chainsaw had the same issue. I took the muffler off and knocked some carbon out and it works flawlessly again.

 

mix a lil seafoam in the gas