201 oil caps

cory

Tree House enthusiast
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Aug 23, 2008
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So they work for a bit over a year, then they start weeping oil. Any tricks or input from y'all re getting better performance outta them? I know the seating surface/rim needs to be clean to work properly. I know I should just buy new ones but its kinda annoying
 
I think there are only two sizes of the Stihl caps. I try to keep at least one of each size stuck back for when failures occur. It seems that when they are negligently forced when out of sync, they don't last much longer. May just be a quirk, but I've had more than one start leaking after a groundie forced them.
 
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  • #4
Good idea, I'll look into O rings
 
I buy the Chinese knock offs on ebay. $3-$4 a cap. They seem to last as long as stock ones.
 
I ordered 10 Oring of both sizes and changes them as needed, not very often. The shop sells only the whole cap, not enough money to make with just the seals.
 
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  • #9
Lotta good ideas, thank you.
 
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  • #11
Ive got a good hydraulics place nearby, I'll have them size em up
 
You might pay a mint for them at a hydraulics store, depending on the size most hardware stores would have them i bet. I got a whole case of different size ones from harbor freight, has helped me more than once. O rings are sized by the id, then the thickness, so measure it up and then call around. I'm sure you could also get a bunch online too, shipped right to you.
 
True, no doubt. I can forage through the O ring drawers at my semi-local hardware stores (True Value and Ace) and pick out matches to a sample I bring in with me for less that a quarter dollar apiece, generally.
 
I think there's even a way to make them too, like you cut to length and then use a certain glue on the ends. I've never done it (that i remember), but saying that makes me want to look that up because that would be handy....

Looked it up, i think I've done it before on a ripped one on a plumbing type fitting...



Also, a great tip for sealing a leaking oring is to dab some teflon pipe dope on it. I do that all the time on water ones, and professional grade pipe dope is rated for gas too, so it should work there too. I recommend the monster brand, it's about the best out there until you get into the anaerobic stuff for chemical plant use.
 
Look closely at the rubber. There are different ones and their behavior with gas and oil can be deceptive if you don't get the good one (either swells, shrinks or even falls apart). The matching parts are designed to match precisely the oring's dimensions after its stabilization in the liquid. In theory. The oring actually has to swell a tiny bit to work properly.
Viton is effectively strong chemically but very stiff if I recall. Not sure if it can work on the flippy caps.

Second point, make sure that your stored Orings don't see the light, are kept clean and away from any mechanical constrain. It's a bad idea to put them as is in the toolbox or on the shelf.
 
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