Stumped on Stihl BR450 Blower Stopping

[Mike W]

Does the primer bulb fully fill with fuel?

Yes, it does.

 

[MtnHaul]

As the owner of 2 BR450 blowers I am very interested in seeing this resolved. If there's anything I can do as far as altering one of my blowers to try and recreate the same symptoms then I would be glad to help.

 

[lehman live edge slab]

I see eBay had new oem carbs for 81$ so between the aftermarket Amazon carb then kit then other oem parts I’m sure a new carb could have just been swapped and been pretty much guaranteed to solve the issue if it is because of the carb. If not then the carb would have been ruled out, rebuilds don’t always work as intended and I don’t care for knock off carbs in general because they seem very hit or miss. Generally the 450 is a very durable blower but obviously they can have issues also like anything.

 

[EFSM]

I see eBay had new oem carbs for 81$ so between the aftermarket Amazon carb then kit then other oem parts I’m sure a new carb could have just been swapped and been pretty much guaranteed to solve the issue if it is because of the carb. If not then the carb would have been ruled out, rebuilds don’t always work as intended and I don’t care for knock off carbs in general because they seem very hit or miss. Generally the 450 is a very durable blower but obviously they can have issues also like anything.

Agree 100% Aftermarket carbs are more hit than miss in a primered setup.

 

[Mike W]

I see eBay had new oem carbs for 81$ so between the aftermarket Amazon carb then kit then other oem parts I’m sure a new carb could have just been swapped and been pretty much guaranteed to solve the issue if it is because of the carb. If not then the carb would have been ruled out, rebuilds don’t always work as intended and I don’t care for knock off carbs in general because they seem very hit or miss. Generally the 450 is a very durable blower but obviously they can have issues also like anything.

I’ve had pretty good luck with aftermarket carbs on small equipment. If the aftermarket carb had runability issues, my troubleshooting mind tells me that the symptoms probably would have changed.

 

[EFSM]

Did you change the intake gasket? Was the pulse hole for sure at the same place?

 

[lehman live edge slab]

I’ve had pretty good luck with aftermarket carbs on small equipment. If the aftermarket carb had runability issues, my troubleshooting mind tells me that the symptoms probably would have changed.

Just stating for all that was spent between an aftermarket carb and then the oem kit to rebuild oem carb after trying the amazon set up in it probably netted about same money and more time in it. Sometimes saving money is about buying oem in the beginning on stuff seems like.

 

[Mike W]

Did you change the intake gasket? Was the pulse hole for sure at the same place?

I know the pulse hole lines up, and the gasket is in good shape (inspected during the most recent work). I’ve done so many different things, I’m thinking I have replaced the gasket, but not 100% sure.

 

[Mike W]

I hope I’ve found the solution to my problem.

 

[EFSM]

View attachment 479117
I hope I’ve found the solution to my problem.

Those things can be hard on the oblique muscles. I don’t think blowers will get much more powerful before people simply won’t run them for extended periods.

 

[lehman live edge slab]

View attachment 479117
I hope I’ve found the solution to my problem.

Good blower just sucks we couldn’t come up with an answer to the real issue on the Stihl, kinda sucks when a person gets so deep and has to quit. Obviously some issue with it that’s fixable but you have exhausted quite a few of them. Now I wonder if this think is like the ms250 I fixed that had a warped pan and would heat up and start sucking air at the seam. This would probably only be the issue if it’s like a clamshell saw and bolted together around the crank though. I haven’t personally had this model apart so not sure of block design. I did some looking and it does have a pan and transfer covers both potential points of air leaks after it heated up and things moved on the block. Just curious what you sealed the engine back up with after bearing change ect? I realize your done with the 450 but this last question was just for my curiosity. My bad I see you used dirko so that’s good long as pan was flat.

 

[Mike W]

Good blower just sucks we couldn’t come up with an answer to the real issue on the Stihl, kinda sucks when a person gets so deep and has to quit. Obviously some issue with it that’s fixable but you have exhausted quite a few of them. Now I wonder if this think is like the ms250 I fixed that had a warped pan and would heat up and start sucking air at the seam. This would probably only be the issue if it’s like a clamshell saw and bolted together around the crank though. I haven’t personally had this model apart so not sure of block design. I did some looking and it does have a pan and transfer covers both potential points of air leaks after it heated up and things moved on the block. Just curious what you sealed the engine back up with after bearing change ect? I realize your done with the 450 but this last question was just for my curiosity. My bad I see you used dirko so that’s good long as pan was flat.

The two case mating surfaces looked good with the naked eye. I didn't measure them for flatness. About all I'm able to conclude is the loose fit of one of the crank bearings is the issue.