C1Q S186 KM55R

PTmowerMech

Lawn Addict
Joined
Apr 16, 2018
Threads
396
Messages
3,016
Looks like that carb has a purge bulb.
Be sure the fuel inlet side holds 7psi.
Then press and release the purge bulb. Pressure should drop slightly an hold each time you press bulb.
Apply 7 psi pressure to purge line barb. Should hold pressure. If those are good look for bad check valve or welch plug fallen out.

I need to do some research on check valves. I've never messed with them.
 

Fish

Lawn Pro
Joined
Aug 2, 2013
Threads
11
Messages
5,130
WOW.. Thanks man. I didn't get this site when I googled this. This is a great price.
That looks like the newer style carb, your throttle cable might not work. That is why I include the throttle cable with mine.

carb38.jpg
 

Hammermechanicman

Lawn Addict
Joined
Jan 10, 2020
Threads
55
Messages
3,526
I need to do some research on check valves. I've never messed with them.
Most check valves are not serviceable. You can usually check them with a piece of fuel line held on it and the use mouth to suck and blow. Should only work one way. If bad need new carb.
 

Fish

Lawn Pro
Joined
Aug 2, 2013
Threads
11
Messages
5,130
Does your old carb have ref. #7?




swivel.PNG7.PNG
 

Fish

Lawn Pro
Joined
Aug 2, 2013
Threads
11
Messages
5,130
The carb in that ad shows a carb that takes the z-bend end.
zbend.jpg
 

PTmowerMech

Lawn Addict
Joined
Apr 16, 2018
Threads
396
Messages
3,016
I think I have the carburetor issue worked out. I got the new US cleaner in today, then reinstalled the kit. Everything seems to be pretty smooth. Except the idle is a tad rough.
The problem is now, just suddenly it'll die. Like you hit the switch. Sometimes, it'll start right back up. Sometimes it's several pulls. BUT, and here's the funny part, it won't just die, at WOT. At idle, it seems like a switch or coil problem. But seems like it wouldn't matter if it was WOT or not, if it was the switch or coil. Right?

I've had about all I can stand with this 2 cycle stuff.
 

Fish

Lawn Pro
Joined
Aug 2, 2013
Threads
11
Messages
5,130
Well, if the carb in the pic is what they are selling, it will not work.
 

PTmowerMech

Lawn Addict
Joined
Apr 16, 2018
Threads
396
Messages
3,016
The carb in that ad shows a carb that takes the z-bend end.
View attachment 54262

I went ahead and ordered one of these. The customer service guy says the arms are interchangeable. According to him, it's an easy thing to do. I've never tried it, though. He said the ones with the wire groove, you can't get anymore.
 

bertsmobile1

Lawn Royalty
Joined
Nov 29, 2014
Threads
64
Messages
24,705
I wish Stens would stock that carb, It seems like that is the most popular part number for carb replacement on Stihl trimmers.
When chasing up service information & parts for a concrete saw, I emailed Walbro as I could not find even genuine Walbro parts for it.
The reply floored me.
Husqvarna paid for the developement of the carb so they owned the IP for it and even Walbro were not allowed to make the carb or any part for the carb without Husqvarna's approval .
So it is a new ( read very expensive ) carb only available through a dealer or nothing .
So Stihl probably have a similar deal with Zama considering they own 1/2 the Chinese factory that makes them
 
Top