I started working on my FS130 because it was hard to start. I looked at the valve settings and the intake was way off. Exhaust wasn't bad. It took about a full turn or more to adjust the intake. Anyway I got the valves adjusted. I still had trouble starting it. I rebuilt the carb. Still hard to start. I found out that these Stihl 4mix machines are prone to getting carboned up. I decarbonized it using the Stihl fluid. It must have taken out a lot of carbon because the valve adjustment was way off after I did it. I reset the valve adjustment to specs. Fired it up and did some carb adjusting and this machine runs like a bear. No hesitation at all. Set RPM's using my tach. Shut it off and you can start it right back up again and it runs fine. But if you let it sit for 20-30 min and try to start it again it is very hard to start if you can get it started at all. Next morning with cold engine it will crank right up. Get it hot and let it sit awhile and it's hard to start. It takes 10-15 pulls to start or maybe it will not start at all. I checked compression and found it at 60lbs. Specs call for 101/87. Squirted a little oil into the cylinder and got 130lbs. I'm thinking rings but could there be something else I'm missing before I go for replacing the rings? Any thoughts on this issue would be appreciated.
If you decide to replace rings be sure to hone cylinder walls with tool & plenty of oil on cylinder walls. Inspect piston, rod & rod bearings, I would replace rod bearings regardless as well as head gasket. Let us know how it goes, thanks, Mark
If you decide to replace rings be sure to hone cylinder walls with tool & plenty of oil on cylinder walls. Inspect piston, rod & rod bearings, I would replace rod bearings regardless as well as head gasket. Let us know how it goes, thanks, Mark
Are you sure about that Mark.
I thought the FS130 had a chrome plated bore
#4
Fish
They have a compression release, put away the compression gauge.
#5
StarTech
It would advisable to do a leakdown test. If over 10% leakage (per SM) then you have a problem which is either the valves, piston, rings, or cylinder problems (such as scoring).
Fish & Star Tech thank you for your thoughts. I knew about the compression release and I did wonder how you could get a good compression reading but the Stihl info I had "Stihl Series 4180 Powerhead" just said to do a compression test. So I did it. I saw in that info I have that the release is on the cam lobe but for the life of me I can't understand how it works. Can someone explain to me how it works? I think I will do the leak down test first per Star Tech and if that shows bad I think I will just disassemble it and check the valves and in general just look it over. It must have had a LOT of carbon in it since that intake valve was being held open. Maybe the De-Carbonizer fluid didn't get all the carbon out. Also, does anybody have a tear down procedure for disassembling and reassembling that engine with torque values and such?
#7
Hammermechanicman
4 mix engines are really particular about valve lash. I would double check it and be sure the valve cover gasket is sealing. The valve cover is part on the engine primary compression. If it starts good cold and runs with good power rings not the problem. When it is hard to start after a few pulls check the plug to see if it is dry or wet. If it is dry squirt a small amount of premix fuel into the carb and see it it fires up. If so you have a fuel delivery problem. Check for any oil staining or leaks around crankcase to cylinder gasket. Check for loose crankcase screws. The compression release is a spring and weight on the cam when engine turns fast enough weight overcomes spring tension and weight moves to where it doesn't affect the vaalve
#8
Fish
P.M. me your e-mail address.
I can send you manuals.
They are too large to put up on this site.
Ongoing FS130 Problems,
I'm still working on this Stihl FS130 trimmer and I need some input on the carburetor. I have rebuilt a lot of these small carbs over the years but I am having trouble with this one. It's a Zama C1QS130C. I disassembled it and cleaned it up with carb cleaner squirting the cleaner through all the small holes etc. Then I ran it through my electronic cleaner bath three times. Put it back together and it will not throw fuel into the combustion chamber. Pull all you want and no gas on the plug. Tore it down again and put the breakdown drawing right in front of me and reassembled it per drawing. I had it right the first time. It won't feed fuel. I bought a $11.00 carb off ebay and put it on the machine and it fired right up. Quality is bad. I had to drill out the throttle cable retainer so the cable would slide in and I had to grind some material off the impulse port so it would slide into the hose. Fuel adjusting screws are stiff and hard to tell when they bottom out when trying to get initial setting. Anyway the Chinese carb works but not as good as the original. Question is what am I missing on that original Stihl carb? Why won't it feed fuel? By the way. Cylinder leak down test showed leak at valve cover gasket. Fixed that. Zero leak down. Pressure tested crankcase. No leak down. Vacuum tested crankcase. No loss at all.
Most of the cube carbs now days use rubber tipped check valves.
The $ 2 cans of carb cleaner attack the rubber so the check valves get stuck.
This is why Walbro has brought out a new formula of carb cleaner.
Since buying the ultrasound carb cleaner gets used to clean the gunk of the outside before I pull them apart.
From then on it is LOW PRESSURE air to check if all the passage ways are clear.
BEfore refitting I hook up the fuel lines , turn the carb side ways and blow air across the venturi and check the carb is aspirating fuel
#11
Fish
New carb at your Stihl dealer: 4180 120 0610 Carburetor C1Q-S173 $35.04
the c1q-s130 supercedes to the s173
Thanks Fish for the new carburetor number. It will come in handy if I decide to replace the Chinese carb that I have on the machine now. I have the trimmer running pretty good at the moment. It starts right up and if I shut it down it will start right up again. I used it today and gave it a hard workout. Only had one instance where it got a little touchy at idle. Somehow the idle changed and it got a little rough. Took it back to my pole barn and adjusted the idle and it perked right up. I think I'll leave the Chinese carb on it and see how things work out. If it keeps getting out of tune I can always put that Stihl carb that you mentioned on it. The idle screw lever point of contact on the Chinese carb was not very good. I had to bend it into position to make better contact with the taper on the idle screw. There was hardly any adjustment to be had and actually I was thinking about bending it a little more to be able to get a more positive contact range. I'll run it some more to see how it all turns out.
