petcock to tank leaking

[deadlyman]

i can't get the petcock to seal to the tank need help

[MarkT]

If it's the threads leaking use Rectorseal T plus 2 on them.  Or yellow Teflon tape.    https://www.amazon.com/dp/B0002YPAFY/ref=sspa_dk_detail_2?psc=1&pd_rd_i=B0002YPAFY&pd_rd_w=gdu9d&pf_rd_p=2bd81721-c115-4b8d-93a3-2ecd17466ded&pd_rd_wg=u0f3b&pf_rd_r=EZ45VKXRZZJQZXCBM2RG&pd_rd_r=17af02b7-2d5b-11e9-b5a3-830356680a3c

Some recommend Gasoila but I haven't used it myself.  Specifically for ethanol blended gasoline.  https://www.amazon.com/Gasoila-Seal-Thread-Sealant-Degree/dp/B00CRKVI4S/ref=sr_1_4?ie=UTF8&qid=1549820771&sr=8-4&keywords=gasoila+thread+sealant

Here's a cheaper one on evil-bay:  https://www.ebay.com/itm/Gasoila-E-Seal-Pipe-Thread-Sealant-with-PTFE-Paste-Non-Toxic-100-to-600-Degr/253969555279?epid=1501517389&hash=item3b21c3df4f:g:AlkAAOSwvMFa5mZm:rk:1:pf:0

[bikerboy1951]

Do you have the little o-ring that is needed to seal the petcock to the tank. It is small but necessary.

Brad

[hubcapsc]

Do you have the little o-ring that is needed to seal the petcock to the tank. It is small but necessary.

Brad

Unless something's bad wrong, Brad's suggestion should be it... I don't think the
threads on our petcocks are the tapered kind that are made to seal...

-Mike

[MarkT]

I agree on that.  Now that I recall there's an O-ring there. BTW threads don't have to be tapered for them to be sealable with the right dope.  In fact the above products even specify IPT sealing, which aren't tapered. The last one, Gasoila with PTFE, specifically for gasoline with ethanol (among others) which is hard to seal.  I didn't know of that product - found it while looking for the answer - and I just ordered a bottle.  My comment applies to other gas leaks at threaded connections - that's what I was thinking of, pertaining to my complex fuel system on Jade which had leaks at threaded joints I had to fix.  BTW I closed off the fuel gauge port on a friend's I/S tank with just a flat plate and a large O-ring.  No leaks.  O-rings DO work.

[deadlyman]

o ring is there new still leaking .
i even tried a larger thickness still leaking

[hubcapsc]

You said:

i can't get the petcock to seal to the tank

Maybe the petcock itself is leaking? OEM petcocks can get hosed up and
do bad stuff... leak gas all over onto your motor and also into the top end.

Onto the motor is a fire hazard.

Into the top end is a hydro-lock ($ + trouble) hazard.

Often the petcock can be fixed with a "cover set", Honda sells it: 16953-MV9-000

Sometimes you have to buy a whole new petcock: 16950-MBY-023

Lots of people buy a "Pingle" (brand) petcock to replace the OEM one...

Here's the insides of a petcock that leaked gas all over the place. It was
on a bike of a friend of mine, the previous owner had tried to fix it by putting
that condom on the weep hole, which made the problem much worse.



-Mike

[The emperor has no clothes]

o ring is there new still leaking .
i even tried a larger thickness still leaking

got the screen in also ?

[gordonv]

o ring is there new still leaking .
i even tried a larger thickness still leaking

got the screen in also ?

Or better yet, is the old one removed from the tank? You want trying to fit a second on in that is on the petcock, and this would make the feed tube bottom out before the mechanism seals.

[deadlyman]

o ring is there new still leaking .
i even tried a larger thickness still leaking

got the screen in also ?

rebuilt it with the hondaline kit definitely leaking from the threads

[The emperor has no clothes]

o ring is there new still leaking .
i even tried a larger thickness still leaking

got the screen in also ?

rebuilt it with the hondaline kit definitely leaking from the threads

The cover set kit doesn't come with the screen. Does your setup look like this before you put it in ?

[Bighead]

o ring is there new still leaking .
i even tried a larger thickness still leaking

got the screen in also ?

rebuilt it with the hondaline kit definitely leaking from the threads

The cover set kit doesn't come with the screen. Does your setup look like this before you put it in ?

Many times the screen will stay in the tank.

[deadlyman]

o ring is there new still leaking .
i even tried a larger thickness still leaking

got the screen in also ?

rebuilt it with the hondaline kit definitely leaking from the threads

The cover set kit doesn't come with the screen. Does your setup look like this before you put it in ?
yes

Many times the screen will stay in the tank.

[9Ball]

o ring is there new still leaking .
i even tried a larger thickness still leaking

got the screen in also ?

rebuilt it with the hondaline kit definitely leaking from the threads

The cover set kit doesn't come with the screen. Does your setup look like this before you put it in ?

Many times the screen will stay in the tank.

Exactly, I've had that happen a couple of times.  Had to use needle-nose pliers to pull the old one out.

Let us know what ultimately fixes the leak for future reference.

[The emperor has no clothes]

I haven't tried it, but it seems with old screen in you wouldn't even be able get a new one in at all. The only other thing I can think of is the threads are cross threaded, not letting you get it on all the way. That is if you are sure it's not the petcock itself, like Mike suggested.

[Cracker Jack]

I agree on that.  Now that I recall there's an O-ring there. BTW threads don't have to be tapered for them to be sealable with the right dope.  In fact the above products even specify IPT sealing, which aren't tapered. The last one, Gasoila with PTFE, specifically for gasoline with ethanol (among others) which is hard to seal.  I didn't know of that product - found it while looking for the answer - and I just ordered a bottle.  My comment applies to other gas leaks at threaded connections - that's what I was thinking of, pertaining to my complex fuel system on Jade which had leaks at threaded joints I had to fix.  BTW I closed off the fuel gauge port on a friend's I/S tank with just a flat plate and a large O-ring.  No leaks.  O-rings DO work.

IPT (Iron Pipe Thread) threads are in fact tapered and are designed to be leak tight.

[MarkT]

I agree on that.  Now that I recall there's an O-ring there. BTW threads don't have to be tapered for them to be sealable with the right dope.  In fact the above products even specify IPT sealing, which aren't tapered. The last one, Gasoila with PTFE, specifically for gasoline with ethanol (among others) which is hard to seal.  I didn't know of that product - found it while looking for the answer - and I just ordered a bottle.  My comment applies to other gas leaks at threaded connections - that's what I was thinking of, pertaining to my complex fuel system on Jade which had leaks at threaded joints I had to fix.  BTW I closed off the fuel gauge port on a friend's I/S tank with just a flat plate and a large O-ring.  No leaks.  O-rings DO work.

IPT (Iron Pipe Thread) threads are in fact tapered and are designed to be leak tight.

Just testing.  Any of my posts may be FOS.  In fact all of them are.  Howzat for ya?  Now you have a blanket disclaimer and corrections are no longer needed...

Meanwhile I don't think the petcock-tank threads are tapered.  But I may be FOS there too.  In any case, I ALMOST ALWAYS use a sealing compound or PTFE tape when assembling threaded fuel/air/gas/water/fluid lines.  Tapered or not.  "designed leak tight" - best laid plans - sometimes they leak anyway so I use sealant.  Except the gauge/metering fitting onto a high pressure tank.  Or oxy/acetylene fittings. Or if there's an O-ring, I might not.

[da prez]

I just measured a tank thread. A 2000 Interstate. The thread measures  .856. Converted to 21.8mm x1mm pitch.
My book calls it 22mmx1.0mm. It does not appear to taper by measurement.
  A dry seal pipe thread has an open flat at the root and Crest called truncation. It allows the mating threats to mesh. This type of thread should have a sealer. If used on natural gas piping,  a special sealer is needed.

           da prez

[gordonv]

How have you made out, got it sealed yet?

I'm prepping for my winter rebuilds, petcock is one of them. Found this one on removal, and he has more.

https://www.youtube.com/watch?v=jkvqIp1Bpns

And this one at the end of the video shows the o-ring on the filter.

https://www.youtube.com/watch?v=RHTt_dhJskc