# Echo Primer Bulb Prob. Need Help



## tperk100 (Feb 15, 2010)

Have an Echo Trimmer/Brushcutter Mod# SRM-230 Ser# 05165131. 

The (new) Primer Bulb does not fill when activated. There are three lines out of the gas tank. I am not certain what the one does the seems to simply go to atmosphere. It seems like it might have a check valve on the atmosphere end.....not sure. Is this a vent?

Anyway I took the other 2 lines that connect to the carb out of the gas tank. I suppose one is a return and the other a supply.

When I clamp off both of these lines, the primer bulb will not depress. This seems good to me. 

However, if I depress the primer bulb, hold it that way, and THEN clamp off the 2 lines, and then release the pressure off of the primer bulb, the primer bulb pops right out.....retains no vacuum whatsoever. Think my carb could be screwed up?

Any suggestions will be appreciated.


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## AVB (Nov 28, 2014)

tperk100 said:


> Have an Echo Trimmer/Brushcutter Mod# SRM-230 Ser# 05165131.
> 
> The (new) Primer Bulb does not fill when activated. There are three lines out of the gas tank. I am not certain what the one does the seems to simply go to atmosphere. It seems like it might have a check valve on the atmosphere end.....not sure. Is this a vent?


Yes it is the tank vent with a check valve.



> Anyway I took the other 2 lines that connect to the carb out of the gas tank. I suppose one is a return and the other a supply.
> 
> When I clamp off both of these lines, the primer bulb will not depress. This seems good to me.


Only checks the back flow check of primer assembly and you can not discharge air as you have the discharge line completely blocked.



> However, if I depress the primer bulb, hold it that way, and THEN clamp off the 2 lines, and then release the pressure off of the primer bulb, the primer bulb pops right out.....retains no vacuum whatsoever. Think my carb could be screwed up?


Not necessarily as it pull air from the main nozzle assembly of the Zama RB rotary carburetorhttp://www.ereplacementparts.com/carburetor-rbk70a-p-1740735.html. This is metered flow nozzle and will air back in but during operation the vacuum created thru the ventura of carburetor allow fuel mix to be pull out instead of allowing air. This has more resistance then supply line normally has which allows the primer to pull fuel/air through the carburetor.

Now there are times that carburetor can have problems too such as a damage metering diaphragm, leaky gaskets, or plug internal filter screen but these usually show up as you won't be able to draw any fuel from the fuel tank.


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## tperk100 (Feb 15, 2010)

Thanks, I have ordered a new carb, fuel lines, and intake gasket...all for about $45 from Amazon


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