Bach pack blower.

[bogdaN]

Start working on Stihl BR-420 blower.Cleaned carb,new spark plug and still not revving up.Pull cover off-found bad seal on bearing. Question i have do i need to take engine a part or there is way to remove that bearing.Thanks for help.Dan

 

[bertsmobile1]

Nope, the entire unit has to come apart.
The fan is a right royal bitch to get off.
Down here the shops cut it off and charge the owners for a new one.
I stuff some nylon rope down the spark plug hole to lock the crankshaft ( make sure it is coming up on compression or you will bend one of the tiny valves).
After that it is a case of hitting the nut with the oxy torch, then penetrating fluid then rattle gun then oxy torch penetrating oil rattle gun at infinitum till it comes off.
You must use a rattle gun & not a long wrench + pipe because the shaft is real easy to bend ( found that out the expensive way ) and as little as 0.0001" off axis will have the operator doing a tango standing still.

 

[bogdaN]

Thank,s for good info.After checking closer-bearing is good only seal is bad.Can i just remove that bad seal and pop new one in ? Here is pic.

 

[Darryl G]

Nope, the entire unit has to come apart.
The fan is a right royal bitch to get off.
Down here the shops cut it off and charge the owners for a new one.
I stuff some nylon rope down the spark plug hole to lock the crankshaft ( make sure it is coming up on compression or you will bend one of the tiny valves).
After that it is a case of hitting the nut with the oxy torch, then penetrating fluid then rattle gun then oxy torch penetrating oil rattle gun at infinitum till it comes off.
You must use a rattle gun & not a long wrench + pipe because the shaft is real easy to bend ( found that out the expensive way ) and as little as 0.0001" off axis will have the operator doing a tango standing still.

Would that seal relate to a running issue of not coming up to speed for the OP?

 

[bogdaN]

Yes,that was the problem.Dan

 

[upupandaway]

Would that seal relate to a running issue of not coming up to speed for the OP?

Doubtfull. It typically will not idle but high speed fine if the seal is bad enough. Check if muffler is plugged.

...only seal is bad.Can i just remove that bad seal and pop new one in ?

You can try. Can drill into the seal, screw in and pull. If your seal is all rubber(looks like it is metal) then get a pic and pull it out.

 

[bertsmobile1]

I thought yours would be the same as the 500, 600 & 900 that I work on regularly.
Looks like the seal pulls strait out according to the parts book.

These are the hybrid 2/4 strokes so a blown seal will drastically reduce the amount of fuel the engine gets.

 

[bogdaN]

I did order new seal.Let you know how things going to work out.I have tools so pulling that seal out no problem.Thanks to U guys for good direction.

 

[bogdaN]

Finley got new seal,put that on---still was having problem revving up.Second attempt to clean carb. was a bust.broke high speed adjstment screw.Ordered new carb---installed and job is done.Again thanks for your help.Dan