Gasoline Fittings Thread Sealant

C

CDory23

New member
I"m doing a complete fuel system overhaul as part of preventative maintenance and because I just completed carb rebuilds and jet changes to my Yamaha Twin 40's. Thanks JOEL-SEA3PO for all of the help! They are running much better then before.

I have completely cleaned all fittings- took some time because the original installer used teflon tape to seal-I feel thats a no no for gas thread sealant.

So what would be the best stuff to use for thread sealant? This stuff?

http://www.starmarinedepot.com/permatex ... oC7GLw_wcB

I may be overthinking this a bit much as I have two filters before anything gets to the engine, but I don't want any chances of any deposits clogging up the new carbs or any part of the system.

Thanks
 
For the fuel systems I use, the fittings arre put together without sealent. I make sure the threads and sealing faces are smooth and crank them together. That seams to hold for bothe pressure and suction.

I have used Permatex products and they are good. That seqalent should work.

Boris
 
I just did a project where I looked into this. Permatex makes a couple of different liquid sealant/gaskets. Permashield is the one that is "fuel resistant" to gasoline. From what I could tell, the manufacturer doesn't want to claim "gasoline proof," but it basically is. Plus, it helps lubricate pipe threads so that it's easier to get them sealed properly. I used it on the hose adapters coming out of my fuel filter. Wear rubber gloves, as the stuff you get on your hands can't be cleaned off with gas.

Mark
 
CDory23,

I have used that same PTFE based Permatex threadlocker on fuel systems, and had good results. If your surfaces are very clean, that is enough. The small amounts which may enter the fuel stream should be caught by the fuel filter. Agree the tape can be problematic.

Permatex produces multiple variations on it, all pretty much the same chemistry but with different fillers, etc. That one is just fine. :!:
 
The mechanics I used to work with used Leak Lock, so that's what I use (not that I put together all that many fuel fittings, but when I do). It's not something I researched personally though. No problems on the fittings I did use it on (on my current boat or reported by current owners of past boat).
 
"I'm doing a complete fuel system overhaul as part of preventative maintenance and because I just completed carb rebuilds and jet changes to my Yamaha Twin 40's. Thanks JOEL-SEA3PO for all of the help! They are running much better then before."
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CDory23, Just curious. I'm guessing you are not replacing the fill ports and caps, tanks or vents. So that would leave the hoses. Curious what you are using for the replacement hose (type) and approx price for the whole hose system.

Harvey
SleepyC :moon

1_10_2012_from_Canon_961.highlight.jpg
 
I see you are asking CDory 23, but I'll chime in too. I replaced my fuel system for much the same reasons (tanks, hoses, vents, separator housing, re-installed fills, etc.). I used Trident Hose, because I like it and am familiar with it, but there are other good marine hoses (Shields, Vetus, etc.).

For the fills I used Trident #329. This is the "Michelin Tire Man" version of their fill hose. I used it instead of the Trident 327/328 (straight versions) because I didn't want the bends to put strain on the filler necks of the tanks (especially the port side one where it dog-legs around the lazarette). The "Michelin Man" version is more flexible (but still plenty stiff for fills).

For the rest of the runs (tank to valve to separator, vents, etc.) I used Trident #365.

I got some Trident #305 (it was recommended to me), but it was a bit too thin and easily kinkable (I felt) for most of my runs. The only place I ended up using it was for one of the internal lines on my Yamaha outboard (#365 would not have fit because the OD is larger for a given size).
 
Hardee,

I only replaced the fuel feed lines from tanks to filter, selector switch to outboard. I can visually inspect the inside of the other lines and they looked fine. Total was about $180 plus tax. I went with A1 rated fuel line from west marine. 10 feet of 3/8 and 10 feet of 5/16 which should leave me with a little left over. It ran 5.99 a foot. I also bought bulbs for $20 each and new yamaha fuel fittings for $10 each. (one had plastic chipping so will get tossed and keep the other as a spare). I took apart all of the fittings and filter/water seperator bracket and put them in the ultra sonic for an hour since I had it handy from my carb rebuild/rejet project. I even took the tank suction hose out to inspect and it looked great. Hardest part was getting all of the little pieces of teflon tape out of threads of fittings.

I even thought of replacing the fuel line in the outboard itself but thought that would be a little overkill since it looked in great condition and has almost zero exposure to the sun.

To my surprise all of the old fuel lines and even the bulbs which I cut in half to inspect looked great. I"m still happy I did this project though as it was original and 13 years old.
 
CDory23":2h06jvst said:
Hardee,

I only replaced the fuel feed lines from tanks to filter, selector switch to outboard. I can visually inspect the inside of the other lines and they looked fine. Total was about $180 plus tax. I went with A1 rated fuel line from west marine. 10 feet of 3/8 and 10 feet of 5/16 which should leave me with a little left over. It ran 5.99 a foot. I also bought bulbs for $20 each and new yamaha fuel fittings for $10 each. (one had plastic chipping so will get tossed and keep the other as a spare). I took apart all of the fittings and filter/water seperator bracket and put them in the ultra sonic for an hour since I had it handy from my carb rebuild/rejet project. I even took the tank suction hose out to inspect and it looked great. Hardest part was getting all of the little pieces of teflon tape out of threads of fittings.

I even thought of replacing the fuel line in the outboard itself but thought that would be a little overkill since it looked in great condition and has almost zero exposure to the sun.

To my surprise all of the old fuel lines and even the bulbs which I cut in half to inspect looked great. I"m still happy I did this project though as it was original and 13 years old.
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Glad to hear the system is still pretty clean after 13 years. Do you know how many hours were on that system when you got it. I seem to remember there might have been some discrepancy. The OB's you did the carb jobs on are the original ones with that fuel system right?

Sounds like you do good work.

Harvey
SleepyC :moon

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When I was doing my tank project I looked at the various fuel line ratings (A2, A1, A1-15). I had some "new" old stuff in the shop that I was going to use, but then I saw that there were new ratings. The newer ratings are based on reduced vapor permeability, not just fire rating. Most of the hose that appeared as bargains on Ebay was the older A2 rated hose.

Mark
 
I used the yellow (not white) pipe thread tape sold as Gas Line Pipe Thread Tape at the big box. It feels and applies like Teflon tape, and the round plastic pack is similar to the ones for Teflon tape. The label on my roll says it is for gasoline, fuel oil, benzene and a number of other hydrocarbons.
 
Hardee,

Yes the OB's I did the carb jobs on are the original outboards twin 2003 Yamaha F40's. There was about 600hrs on the motors when I purchased and now there is about 760. I feel I should be able to get at least 2000hrs out of these motors especially since I seem to be doing all the work on them now.

I decided to go with this as my sealant:

http://www.jamestowndistributors.com/us ... +3+Sealant
 
CDory23":2eli0zoq said:
Hardee,

Yes the OB's I did the carb jobs on are the original outboards twin 2003 Yamaha F40's. There was about 600hrs on the motors when I purchased and now there is about 760. I feel I should be able to get at least 2000hrs out of these motors especially since I seem to be doing all the work on them now.

I decided to go with this as my sealant:

http://www.jamestowndistributors.com/us ... +3+Sealant
Click to expand...

Thanks for that reply. I would think you should be able to get well over the 2000 hours if you take good care of those OB's.

Harvey
SleepyC :moon

1_10_2012_from_Canon_961.highlight.jpg
 
I like Loctite 567 for everything - gasoline, diesel, propane, hydraulic, water, compressed air, even the kitchen sink.

It is expensive, but the $20 tube will last for years. It is usually advertised for use on stainless steel fittings because of its lubricating properties to prevent galling, but it is great on all common materials. It also is good on the plastic fittings in the freshwater tanks because it seals well without having to over tighten the threads.

Loctite makes an aerosol primer that speeds the curing to minutes instead of hours for high pressures or sealing looser joints.
 
I agree.

Only have used the Permatex aviation sealant shown in the previous message for fuel connections (tank pick up elbow, ASV threads, external fuel filter fittings) and bought a tube of Leak-Lock but have not used it
 
T.R. Bauer":3rhef9pc said:
I'm at a loss as to why you'd use anything at all on it. I should not be necessary. And it if is, you probably need a new fitting.
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Some of us worry too much. :lol:

Brass fittings conform very well to the hole they are stuck in and rarely need any help from a sealant.

Steel in steel fittings are generally good dry, but the lubrication and corrosion resistance of a good sealant is a good idea.

Stainless fittings can gall easy and they don't conform to a poor fit very well so a good lubricant/sealant is always recommended.

It is easy to over tighten a tapered thread fitting screwed into aluminum or plastic so a good sealant that remains somewhat flexible gives peace of mind and a lasting seal even as the material relaxes.

When the fitting and the hole it goes into are different metals, a good sealant should be used if only as a corrosion inhibitor, especially on a boat.

As long as it is applied sparingly and above the end of the threads so it does not get inside of the lines, a good sealant should always be used if only as a thread lubricant.

Teflon tape is good enough for water joints, but I don't like it for much else. It is very easy to get strings of it into the product stream.

Anyway, that's what I came to believe after all those years at a paper mill fixing leaky stuff. The first few years I was often fixing my own leaks, so once I discovered how good that Loctite 567 stuff worked I never bothered using anything else.
 
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