Stihl BR500 leaf blower needs help ( RPMs )

[builttoughf350]

I just bought a used Stihl BR500 leaf blower, which doesnt rev up very high. when running it sounded good, but sounded like it was running 60% of what it should for RPMs. Its definitely not impressive with the throttle wide open.

So far, what I have done is-

Replace spark plug
cleaned exhaust screen ( AKA spark arrester? )
new fuel
checked air filter, its clean.
tried a little sea foam to clean things out.
tried to adjust the carb. no luck.


the closest store to get a fuel filter is closed today, Im not sure how soon I can get to the place to pick up a new fuel filter.


can someone tell me exactly how to adjust the carb ? The still manual online says to turn both screws counter clockwise until they stop, then turn clockwise 3/4 turn. so I did that, and then it wouldnt idle. I adjusted the LA screw next to the choke clockwise until it would idle, but then it bogged when giving it throttle and still wouldnt rev up full RPMS. I gave up at that point before I blow it up.

Can someone teach me how I should try to adjust the carb and LA setting, so I can see if Ive done it right, then if it still doesnt rev up ill get a fuel filter.

thanks !

 

[old-cat]

Make sure the compression is good and the piston is not scored, FIRST. Then I'd say get the limiters off the mixture screws and adj. H & L 1 turn out, then fine tune from there.

 

[Andyshine77]

You need to set proper valve clearance, it's an easy process. Your dealer will have a new valve cover gasket and feeler gauge.

 

[LegDeLimber]

I think that username bsnelling aka Brad Snelling wrote of doing some Stihl 4-strokers somewhere.
Was a while back that i read it and I'm honestly not certain that I saw it on this site.
might shoot a pm to him.

Edit: It might be in this thread.
http://www.arboristsite.com/communi...ower-on-the-market.166938/page-8#post-2887886

 

[BC WetCoast]

I had a similar problem, removed the spark arrester completely. It now sounds like a dirt bike but runs a lot stronger. Haven't bothered to go and get a new one.

So I would suggest removing the spark arrester completely and see if that helps.

 

[SEAM]

Be careful - a leaf blower will always run under load as the fan is sitting directly on the shaft. When setting to max. speed there is a danger to adjust the carb too lean...
I don't know about the 4-MIX engines, but 2-stroke blowers (I own a BR400) don't rev up like chain saws either.

 

[CR888]

With all due respect if the op needs advice on adjusting idle (no problem with that), he probably needs to understand a couple of things first with blowers compaired to other 'unloaded' OPE. Your blower engine is capable of doing alot more rpms than it will ever do attached to a big fan (load). Bloweres usually should produce 6500-7500 rpm at WOT (wide open throttle) under load. lf it were not under load it would produce several thousand more rpms. Hope this helps a bit.

 

[builttoughf350]

Well Ive done everything I can and its starting to seem like it may be the valves. So I have some learning to do.

 

[CR888]

There is some good info on what you need to do it yourself if you want to go down that route. Can you tell us how many rpms the machine is currently producing at full throttle?