Stihl FS38 trimmer primer bulb sucking air in and runs badly

StarTech

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  • / Stihl FS38 trimmer primer bulb sucking air in and runs badly
NO they do not contain every wearable part just the common ones.

Well there are GND and Carb repair kits but if the primer base check valves are bad neither will repair that. Nor do they repair a bad main nozzle and damage check valve in the carburetor body. For the DIYer that has no idea of how these carbs work or how to check them then it best just to replace the carburetor.

I clean and repair a lot of these carburetors but even there are times they simply can't be repair due lack of parts ot the parts are too costly.
 
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XGamer223

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  • / Stihl FS38 trimmer primer bulb sucking air in and runs badly
NO they do contain every wearable part just the common ones.

Well there are GND and Carb repair kits but if the primer base check valves are bad neither will repair that. Nor do they repair a bad main nozzle and damage check valve in the carburetor body. For the DIYer that has no idea of how these carbs work or how to check them then it best just to replace the carburetor.

I clean and repair a lot of these carburetors but even there are times they simply can't be repair due lack of parts ot the parts are too costly.
Alright, thanks for the advice! New carb it is then
 

StarTech

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  • / Stihl FS38 trimmer primer bulb sucking air in and runs badly
Alright, thanks for the advice! New carb it is then
Slight correction to post #21 and it is important as they don't contain every wearable part. Sorry for leaving out that word. I was tired and it is hard to read post without my readers. I had to step on them yet again so I off to the store for another pair.
 

XGamer223

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  • / Stihl FS38 trimmer primer bulb sucking air in and runs badly
Slight correction to post #21 and it is important as they don't contain every wearable part. Sorry for leaving out that word. I was tired and it is hard to read post without my readers. I had to step on them yet again so I off to the store for another pair.
No worries, I figured it out :)
 

Weasel811

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  • / Stihl FS38 trimmer primer bulb sucking air in and runs badly
Here is the one I sell, the cable has the z-bend end.
View attachment 57605
Fish, would you ship that to Canada? I don't need the throttle cable though, mine has the z bend at the end. Email please: ryanweselake@gmail(dot)com
 

shoechstenbach

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  • / Stihl FS38 trimmer primer bulb sucking air in and runs badly
I see that this chat is quite old buy hopefully this will help the next guy from spending hrs on trying to figure out why the primer bulb won't prime! I too spent hours trying to figure this out having eliminated that it was a cracked bulb, bad fuel line, bad diaghram, bad carb, etc. I was almost convinced to spend the $50 on a new OEM carburetor. However after after some careful thought I removed the primer bulb base and figured out out that the 2 holes in the primer base are actually valve inlets. These inlets become clogged much like a fuel filter. The answer to this problem is to take some thin gauge Christmas tree ornament wire but wire and rheem out the 2 bulb base inlet holes to remove the dirt and gunk that is clogged up within the plastic bulb primer base. Spray in some WD40 or carb cleaner into the holes and the primer brass inlet tube. Reassemble and she primes like a screaming banshee. I searched and searched all over the internet and could never find any info on this....sometimes you just need to think through things logically...in this case I figured there was nothing magical about the primer base....just another point for dirt and gunk to magically accumulate!
 

bertsmobile1

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  • / Stihl FS38 trimmer primer bulb sucking air in and runs badly
Usually those one way valves either stick closed because the rubber has gone soft & sticky or sty open because the rubber has gone hard m cracked & fallen off.
You have been lucky so far but do not be surprised if it fails again next season
t is good pretice to tip out the fuelat the end of each season then run the the engine dry
 

sgkent

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  • / Stihl FS38 trimmer primer bulb sucking air in and runs badly
the problem I always have with those carbs are the thin diaphragm flaps warp. They are check valves for the fuel on the ones I have. If those flaps are warped the air/fuel just sloshes back and forth rather than gets pulled up from the tank. I have never been able to find a reasonable priced carb kit. All the ones I see have been $2 or $3 less than a new oem carb.
 
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