Felt up

[dexter]

After reading hundreds of posts here and everywhere about carburetor felt installation, lubrication (dry, silicone, light oil) and of course, the mysterious hole behind the felt....I did as follows; soaked the felt with 30w motor oil, plugged the holes with epoxy, and, dressed the face of the felt cavity where the steel or fiber washers ride. I can just get a razer blade behind the washers to re-lube in the future. I'll let you know what if anything happens, I still want to know what the holes are for? Dexter

[robin1731]

Why did you plug the hole??!!

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[pjlogue]

The holes are for "drying" the felt out if they get wet. It lets air circulate through the felt when the engine is running.

-P.

[dexter]

The felt was burnt out at the hole, I guess from gas and back fire. A random leak is the last thing I need to get four carbs to work together via mixture and vacuum sync. The felt can't get wet, not that it would matter.

[robin1731]

You don't have to take the word of a Randakk approved rebuilder. Read below about those felt "seals".

viewtopic.php?f=54&t=67538

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[dexter]

Great Post, All back together with best performance ever.
Three new things done, New felts (30w oil soaked, filled mystery holes), set floats at both right and left ends instead of just at valve end, fixed air leak in base of idle control valve. The old O rings were stiff from ethanal, but appeared to still function? Runs smooth and strong, compression is 125 dry on one cylinder, 160 x3?? I suspect the ACV leak was some of the problem and recommend, when installing carbs, to slide in the carb rack and pull it to rear to install idle control valve clear of frame to get both screws torqued down even. I also did the current off idle fix specific to 76 GL's. By gota ride

[robin1731]

Idle control valve? Do you mean the air cut off valve?

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[dexter]

Yes

[Sidecar Bob]

How old are the o-rings? Do you think it might be possible that it is decades of heat and contact with gasoline that have made them harden rather than ethanol?
Read this: https://www.ngwclub.com/forum/viewtopic ... 54&t=69205

[dexter]

The o rings were about 6 years old from a kit. They were black, assumed not Viton.

[Sidecar Bob]

Which kit? Some are good and some not so much. https://www.ngwclub.com/forum/viewtopic.php?f=1&t=37139

FWIW, I put a Randakk kit in my carbs and the last time I looked inside them the black o-rings had not hardened noticeably after 8 years of use exclusively with E10 fuel.

[robin1731]

Yeah, 0-rings get hard from heat. If the fuel did anything it would make the swell and get "mushy". (technical term)

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[dexter]

It was a Randakk kit, but from before the ethonal scare. Per above I think the seals were functioning. It sat for more than a year dry so they may have swollen, then hardened. Still running great, I "was" looking for another bike! The only sure thing, thats different from before, is the older and more patient carb rebuilder, me.
Thanks All

PS, If, as some think, the mystery hole is for lubrication with fuel, be advised I had no apparent shaft wear at 40K.

[Sidecar Bob]

The parts that reacted with methanol swelled and became porous.