Fuel leak at carb |
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8122pbrainard
Grand Poobah Joined: September-14-2006 Location: Three Lakes Wi. Status: Offline Points: 41040 |
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Posted: September-24-2010 at 7:36pm |
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John,
Thank's for the link. John's link That fishing site forum does have some smart people on it that know how to handle the fuel lines from the pump to the carb. Here's a copy/paste: "Quote: Originally Posted by inetmug Hey Guys, I imagine the fuel line setup from the FP to the carb is supposed to be hard plumbed like in my old IO's. I hate to admit this but I just noticed the previous owner jury rigged it with standard CG fuel line to a barb fitting, most likely when they replaced the carb in '05. The line is not in danger of chaffing or near anything hot, but still it is not right I imagine. What is the proper setup for this, and can a steel braided line be used? I am told yes. My local Holly speed shop has SS brained line with alunimum fittings but they could not comment on ethanol with the lines, and since they all pump high octane stuff they do not see ethanol." Reply from Jimmy's marine service: "personally,i would never use that set up-i realize the cg states it's ok,but it doesn't pass my test... get the correct line to fit it-order it from the mfg of your engine. i've ran into this alot as well,owner's some times lack tools,they use a regular openend wrench on the fittings,round them off,instead of using the correct flare nut wrench...the "pre shaped" lines are available from crusader,mercruiser and pcm...use a dab of grease on the line then,slide the nut over it,this will avoid the nut siezing to the line..." |
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john33617
Senior Member Joined: July-07-2004 Status: Offline Points: 182 |
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http://www.fishtheclassic.net/forums/showthread.php?t=23711
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skyhawkflyer
Senior Member Joined: February-08-2005 Location: Zimbabwe Status: Offline Points: 275 |
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I could care less what class fit they are. Have you measured them? Let me know what you come up with.
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john33617
Senior Member Joined: July-07-2004 Status: Offline Points: 182 |
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with the steel line in place after time the JB weld would crack and leak , with the hose the JB weld has held for years
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8122pbrainard
Grand Poobah Joined: September-14-2006 Location: Three Lakes Wi. Status: Offline Points: 41040 |
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What class fit are they? H2,H3,H4? Have you measured? |
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behindpropeller
Platinum Member Joined: July-31-2006 Status: Offline Points: 1810 |
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skyhawkflyer
Senior Member Joined: February-08-2005 Location: Zimbabwe Status: Offline Points: 275 |
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Actually John is correct. The threads are weak because they are a poor fit, loose tolerance with the adapter. If the threads on the bowl were manufactured to the precision standard of connecting rod cap bolts then there probably wouldn't be an issue. There is no comparison here. And I certainly would not use a higher torque on the adapter just because it has fine threads.
SAE torques are higher for fine thread as these are generally manufactured as a high(er) strength fastener. Course thread fasteners are generally low torque, although they can be purchased in grade 5 or grade 8, or can be purchased without a grade rating as well. No rocket science here. Not all boats have the same engines and setups, some experience this and others don't. And I was not using the JB Weld to stop a leak, I used it to coat the threads so the fitting doesn't loosen. |
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Randy_in_Ohio
Platinum Member Joined: September-13-2006 Location: N. Canton, OH. Status: Offline Points: 1891 |
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As much as I love JB weld, and I find new uses for it all the time, I would never use it on my boats carburetor and fuel line. Seems really half-assed to me.
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82 Nautique 1
Senior Member Joined: January-06-2007 Location: Rock Island, IL Status: Offline Points: 265 |
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If vibration is that bad, may want to check the prop shaft :)
I have owned my Nautique for 29 years and have yet to have the fitting vibrate loose. Guess I am the lucky one. I would find the answer to my problems causing the leak and again fix it correctly instead of patching it with JB weld |
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8122pbrainard
Grand Poobah Joined: September-14-2006 Location: Three Lakes Wi. Status: Offline Points: 41040 |
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John, Fine threads are weak?? The zinc alloy of the carb body may not have the tensile strength of steels but that's why it's tapped with fine threads! You're off in a direction that you shouldn't be since you have no background to back it up!! Again!!! Tell me, why are fine threads used on demanding high strength loads such as connecting rod caps!!!??? Tell me why SAE torque spec's are higher for fine threads than coarse threads!!!??? Do you buy JB Weld in bulk? |
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skyhawkflyer
Senior Member Joined: February-08-2005 Location: Zimbabwe Status: Offline Points: 275 |
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Oh brother, you have got to be kidding me...
There is more than one way to fix this problem and it is NOT high pressure fuel. The pump maybe puts out 14 psi, but I doubt it. First of all, I always use clean fuel, so I've never seen rusted up fittings like you have posted pictures to. If you dump dirty fuel in the tank then I can certainly see your need to pull that filter every month or so. I vaguely remember a fine mesh screen as described however at my last carb overhaul 3 years ago it was perfectly clean. I keep my fuel clean and that eliminates about 90% of problems in itself. It's a poor design and it is a problem that keeps rearing it's ugly head. Buying new parts does not always solve the problem, and doing so doesn't permanently fix it either so I think you are giving bad advise as well. JB Welding an adapter in place doesn't destroy a carburator either. a safety wire hole could be drilled to secure it too. I have seen people struggle with this setup until the copper line gets over torgued and the flare cracks and then the boat is unusable. You just don't keep smoking it down tight with two wrenches. I have used the pipe thread sealant which I know you think is a pretty stupid idea, but it seals the threads (if the flair is leaking) and it also has a bonding agent in it that sets up so it doesn't loosen from vibration, yet it doesn't have the teflon tape shreds to foul the carburator. I know, it's a really dumb idea... |
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john33617
Senior Member Joined: July-07-2004 Status: Offline Points: 182 |
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the threads in the bowl are very fine and weak , heating and cooling of the engine puts pressure on them , thats why so many have leaks there , vibration and twisting also
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8122pbrainard
Grand Poobah Joined: September-14-2006 Location: Three Lakes Wi. Status: Offline Points: 41040 |
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Sorry John but you also are giving out bad advice. JB welding is not how a flare fitting is designed to work. You also need to review the USCG regs on plumbing on the high pressure side between the pump and carb. Barbed fittings? Maybe you could get away with the hose if you drilled more holes in the choke plate? When are we going to see some pictures of your boat and engine? |
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john33617
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the problem is the steel line it keeps pressure on the fitting , JB weld the fitting in place , replace the steel line with a USCG hose , barb fittings on fuel pump and carb
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Randy_in_Ohio
Platinum Member Joined: September-13-2006 Location: N. Canton, OH. Status: Offline Points: 1891 |
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Are you sure? I have a 93 with the Holly 4160 and there is a screen in that adapter. It's kinda in the middle of the adapter, I didn't notice it the last time I had it apart, but noticed it when I had it apart last week. Mine was clean, but still not a bad thing to check. |
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skyhawkflyer
Senior Member Joined: February-08-2005 Location: Zimbabwe Status: Offline Points: 275 |
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Nope, I ordered a replacement and a identical part came in. I'm leaving it as is, no leaks and it works great. I also use a filter funnel when fueling and haven't had a problem since I bought the boat in 1993. Mine is not like the picture.
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8122pbrainard
Grand Poobah Joined: September-14-2006 Location: Three Lakes Wi. Status: Offline Points: 41040 |
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The external fuel filters separators have been used since the 80's. Keep a eye on it since I have a feeling your gas isn't the greatest in your location.
Someone took the filter screenout of your carb!!!!! The fitting pictured on the right shows it. I suggest getting it back in there. Good luck getting the epoxy busted loose. |
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skyhawkflyer
Senior Member Joined: February-08-2005 Location: Zimbabwe Status: Offline Points: 275 |
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My 4160 just has a line adapter to the carburator, no filter underneath it, so no need to ever remove(I have a huge external water seperator/filter assy). I should have added that I was using a new line, washer, and adapter in an attempt to repair the leak permanently before a fire broke out. The new parts also leaked, and several of us came up with the JB Weld idea simply because in my application there is no need to ever remove it, this won't work for all as some carbs do have a filter.
I knew somebody wouldn't like this idea, but hey it worked very well for my setup, and it's been holding for almost 2 years now without leaks. |
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behindpropeller
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82 Nautique 1
Senior Member Joined: January-06-2007 Location: Rock Island, IL Status: Offline Points: 265 |
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Pete,
I agree. Why jury rig something that could and should be done right ? Not worth the risk. Buy the parts, fix it right, it is a Nautique. |
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8122pbrainard
Grand Poobah Joined: September-14-2006 Location: Three Lakes Wi. Status: Offline Points: 41040 |
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Thread sealant, liquid steel and no filter screen behind the flare adapter? Sorry but this is just poor advice. |
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skyhawkflyer
Senior Member Joined: February-08-2005 Location: Zimbabwe Status: Offline Points: 275 |
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Been there several years ago and fixed it... Here's how!
Remove the line, remove the fitting. Clean up the fitting well, mix up a small amount of Liquid Steel epoxy and apply to the threads and a dab on the thin washer. Screw it in and tighten it with a 1" 12 point socket and rachet. Let it cure, then reinstall your fuel line using pipe thread sealant (not the teflon tape) No more leaks, and it won't loosen up on you. Others may argue not to do this, however once installed you should never have to remove this fitting, even when overhauling the carb, there are no filters under it. Since I did mine I haven't had the problem of it leaking again and presenting an explosion hazard when I'm out skiing. |
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8122pbrainard
Grand Poobah Joined: September-14-2006 Location: Three Lakes Wi. Status: Offline Points: 41040 |
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Randy, I'm glad it worked and happy to help out. Yes, aligning a hard flared line on both ends can be a challenge and I almost mentioned it in my grease under the nut post. The ends never seem to line up and care must be used to avoid cross threading the flare nuts. |
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Keeganino
Grand Poobah Joined: October-27-2009 Location: North Carolina Status: Offline Points: 2063 |
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Good thread. I had the same problem when I got my motor back from the mechanic- go figure. Luckily all I had to do was take the metal gasket out, clean all the surfaces and it sealed right up. Have been keeping an eye on it and have not had any leaks since.
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"working on these old boats may not be cost effective but as it shows its what it brings into your life that matters" -Roger
1973 Skier |
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Randy_in_Ohio
Platinum Member Joined: September-13-2006 Location: N. Canton, OH. Status: Offline Points: 1891 |
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I never got to go to the lake this weekend but I do think I put a stop to this leak once and for all. Using a 1" socket to tighten down that adapter was key. Pete's tip using the grease on the flange fitting was brilliant as well. I ran it in the driveway for about ten minutes and no leak!
One thing I would add is that after you have tightened down that adapter with the 1" socket and you are reattaching the fuel line, get both ends of the fuel line attached but not tight, then tighten them down alternating between both ends until tight. Be sure that both ends are well seated before final tightening. Big thanks to Alan and Pete. |
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OverMyHead
Grand Poobah Joined: March-14-2008 Location: MN Status: Offline Points: 4861 |
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Pete, different place. This was in St Paul MN. Put in the new metal ring, cranked the flare adapter prety tight, then lubed the outside of the flare and tighend that fitting . Ran on the hose for about 5 minutes with no leak. will continue to watch. Thanks everyone.
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For thousands of years men have felt the irresistible urge to go to sea, and many of them died. Things got better after they invented boats.
1987 Ski Nautique |
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8122pbrainard
Grand Poobah Joined: September-14-2006 Location: Three Lakes Wi. Status: Offline Points: 41040 |
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Dave, Must be a different carb shop. I've dealt with this place on a couple occasions. Once was looking for the Zenith T3X carb for my old 1927 Universal I rebuilt. He was the guy that said he had several but wanted $1600 for one rebuilt! The other time was to get a rebuild kit for the carb I did use for the engine that came off a Wisconsin 4 cylinder industrial. Glad you found the sealing washer as well as the other gaskets. Keep us informed on how the project of stopping the leak goes. |
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OverMyHead
Grand Poobah Joined: March-14-2008 Location: MN Status: Offline Points: 4861 |
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Noi Luck at NAPA but they recommende the carb shop. The palce must be good . they had a bout 15 carbs on their front desk and at least 100 in site. The guy new thae carbs and sold me on each of the two size seals that tehy use on the intake for a $1.25 each. Said he would rebuild the carb for about $190. I told him I had an issue with the low spped mis screws. He said they get messed up but as long as it idles ok dont mess with it. So I hope I will be good for now.
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For thousands of years men have felt the irresistible urge to go to sea, and many of them died. Things got better after they invented boats.
1987 Ski Nautique |
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Randy_in_Ohio
Platinum Member Joined: September-13-2006 Location: N. Canton, OH. Status: Offline Points: 1891 |
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I've had this same issue on and off since I got my boat. I had Eric tighten it down when he had the boat last year and it was fine until the last time I took it out and noticed it was leaking again. I was able to tighten it up enough to get me through the day, but I'm always checking for a gas leak there. I have replaced the fuel line and the gasket. I was planning on rebuilding the carb this winter and figured I would get it sorted out then but I may take a look at it tonight over a couple brews. I may hit the lake tomorrow and I want to make sure this thing isn't leaking.
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81nautique
Grand Poobah Joined: September-03-2005 Location: Big Rock, Il Status: Offline Points: 5767 |
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the gasket is metal and you may have to order it from Summit, none of my local autoparts stores could get it unless I wanted to buy a complete rebuild kit.
gasket Edit : whoa, beat me to it and much cheaper! but yes that's the right part. |
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