Are Stihl Flippy Caps Supposed to Squeak and Leak?

[Cantdog]

Leak?..........can't imagine why a flippy cap might fail.....geeze..... the one at the top of the pic is 2 years short of a half century old and it doesn't leak or ever failed me in any way.........

 

[rocketnorton]

"tool less", right from the horses mouth

guess there's never been a leaky screw in cap
or one f'd up by use of tools to remove

 

[belgian]

It must be that the toolless cap has been invented by one member of the Stihl family itself, as no one in the Waiblingen engineering department apparently dares to admit that the flippy cap was an obvious faulty design from the start. These caps have upset almost every user of their product and represent a clear safety issue. But on the other hand, they must like the service revenues generated by the multiple replacements, I guess.

 

[cookies]

the cap o rings are like 7-8 bucks last time I got a couple...about double for the whole cap. If the Oring has a flat face replace it, the problem is the plastic cam and its shaft in the cap wear down so the seal is not fully pushed against the sealing surface or it will leak in the center of the cap past the shaft.

 

[muddy42]

In my view, without doubt the worst piece of chainsaw design in the last fifty years.

 

[HansFranz]

Gotta love it when the fuel cap requires four pages of exploded parts diagram sub-assemblies on the IPL.

 

[muddy42]

It must be that the toolless cap has been invented by one member of the Stihl family itself, as no one in the Waiblingen engineering department apparently dares to admit that the flippy cap was an obvious faulty design from the start. These caps have upset almost every user of their product and represent a clear safety issue. But on the other hand, they must like the service revenues generated by the multiple replacements, I guess.

Hopefully someone at Stihl reads this thread

 

[Section VIII]

I've yet to have a problem with a flippy cap. Been only 11 years for me though.

 

[muddy42]

I've replaced 2 flippy caps in the last year. These saws are 3 and 10 years old and second hand so I can't vouch for how they were used before me. I think some people force them on or the caps get dirty.

Id be interested to know if someone made an adapter to return to a threaded cap (the opening might need to be narrower to allow for this).

 

[oldbuzzard]

Stihl flippy caps are beyond any doubt the most useless piece of gear ever inflicted on sawyers and I cannot, for the life of me, understand why Stihl hasn’t come up with a replacement. They are the main reason I run Husky and not Stihl.

 

[Vintage Engine Repairs]

Because the flippy cap on my Stihl MS361 just started squeaking and leaking. I blew off both sides of the cap with compressed air, and the rubber o-ring is unbroken and seems fine, but still she leaks! It kinda almost feels like it got degreased with some hardcore solvent somewhere along the way but to my knowledge that has never happened, and it's never even seen gasohol.

Is there any way to fix it (assuming it's not supposed to leak when you turn it with its left side downward)? Or do I just need to buy a new flippy cap?

Thanks for any clues.

There is a recall on them, there has been for years due to the poor quality fuel in the USA damaging them. Check for the letter on the inside of the cap. D has recall on them.


https://www.stihlusa.com/safety/recalls/toolless-fuel-cap/

 

[PV Hiker]

Rubber o ring does not last forever and is a disposable part that is simple and a
easy to replace. Each time you close it, it is compressed, how many cycles and how clean is the mating surface over the years has it been. Last year my 361started to leak and replace just the o ring. Been good for a year so far.

 

[Chevboy0167]

 

[TheTone]

I agree with @PapaWhitebeard. I found some quality O-rings online with the Stihl dimensions. About 20 or so, not expensive at all. An o-ring can look OK and still be somewhat flattened from age and use. If you're curious, try flipping the cap over and see if the leak is improved. If it is, the o-ring rather than the cap itself is the culprit. Either way, replace the o-ring and check again. This will usually fix the problem. It's lots cheaper than buying a new cap.

 

[HansFranz]

try flipping the cap over and see if the leak is improved. If it is, the o-ring rather than the cap itself is the culprit.

Well, I'll be darned. Flipping over the o-ring fixed it! No more leak.Thank you! (I can't believe I didn't think to try that myself.)

 

[PapaWhitebeard]

Well, I'll be darned. Flipping over the o-ring fixed it! No more leak.Thank you! (I can't believe I didn't think to try that myself.)

woot! nice going, fella!

FWIW I've purchased silicon o-rings that are RED in color... like a light red-ish and they are incredibly strong and robust. Doesn't matter what color they are of course... the point is the silicon o-rings IME are worth the trouble of tracking them down.

If you come across them maybe check them out (shrug)

 

[HansFranz]

Thanks for the tip on the silicone o-rings. In addition to the new cap, I did end up buying ten nitrile o-rings for ~ 35¢ apiece...

 

[RCamo]

I agree with @PapaWhitebeard. I found some quality O-rings online with the Stihl dimensions. About 20 or so, not expensive at all. An o-ring can look OK and still be somewhat flattened from age and use. If you're curious, try flipping the cap over and see if the leak is improved. If it is, the o-ring rather than the cap itself is the culprit. Either way, replace the o-ring and check again. This will usually fix the problem. It's lots cheaper than buying a new cap.

What are the dimensions and/or can you tell me where you got the O-rings from? Thanks!

 

[HansFranz]

What are the dimensions

According to the Stihl IPL for my MS361, 25x3.5mm (Stihl part number for the o-ring alone is 9645 948 7734).

Lots of o-rings with those dimensions on ebay.

 

[ballisticdoughnut]

According to the Stihl IPL for my MS361, 25x3.5mm (Stihl part number for the o-ring alone is 9645 948 7734).

Lots of o-rings with those dimensions on ebay.

New flippy caps have a silicone o-ring. Easy way to tell is new caps have a blue o-ring old is black. On some saws they still use a NBR o-ring for small oil cap. On Monday I’ll post a few pics of what we sell at work. If I can find any relevant data from Stihl I’ll post that as well.