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View Full Version : Fuel Leak -- gasket/fitting question 4160 carb


strad
03-13-2013, 07:06 PM
I pulled the boat out and fired it up today, and while it was running I noticed a small fuel leak from the large fitting where the fuel pipe goes into the front bowl of the carb. On mine there is a large fitting (1 inch or so) that attaches to the front bowl and then there is a smaller fitting that attaches the fuel pipe to the large fitting. My leak is from between the large fitting and the bowl. It looks like there might be a gasket in there?

At any rate I did put a wrench on the fitting and moved it slightly, which made the leak slow down, but it didn't "feel" right so I didn't try to tighten it more. Guidance? I've got somebody who grew up playing with carbs coming in two weeks, but I want to use the boat this weekend lol. I know it's an elementary question -- I've learned to ask first before breaking expensive things though hehe.

thatsmrmastercraft
03-13-2013, 07:21 PM
Yup, there is a gasket in there. Sounds like you need a new one.

http://www.holley.com/data/TechService/Technical/4150%204160%20Exploded%20View.pdf

Cloaked
03-13-2013, 07:37 PM
I pulled the boat out and fired it up today, and while it was running I noticed a small fuel leak from the large fitting where the fuel pipe goes into the front bowl of the carb. On mine there is a large fitting (1 inch or so) that attaches to the front bowl and then there is a smaller fitting that attaches the fuel pipe to the large fitting. My leak is from between the large fitting and the bowl. It looks like there might be a gasket in there?

At any rate I did put a wrench on the fitting and moved it slightly, which made the leak slow down, but it didn't "feel" right so I didn't try to tighten it more. Guidance? I've got somebody who grew up playing with carbs coming in two weeks, but I want to use the boat this weekend lol. I know it's an elementary question -- I've learned to ask first before breaking expensive things though hehe.Recommendation from experience: When attempting to remove the line from said connection, I recommend loosening the threaded connection, then removing the 4 base nuts on the carb and lift the entire carb away from the fuel line, in lieu of trying to force the line out of the threaded connection port. That line will bend ever so slightly and you'll never get a great and perfect threaded fit when putting it back together (again having to wiggle the connection into place).

Lift and reset the carb away from and back onto, the fuel line. That said, order two new base gaskets. Seems like a lot of trouble but I have cross-threaded more than once (practically irreparable) in this very scenario. Will take maybe an extra 5 minutes total and well worth the patience. Do not ask about a torque spec.. :D Tighten only to snug tight to seal the gasket.

$0.02

.

thatsmrmastercraft
03-13-2013, 07:45 PM
Recommendation from experience: When attempting to remove the line from said connection, I recommend loosening the threaded connection, then removing the 4 base nuts on the carb and lift the entire carb away from the fuel line, in lieu of trying to force the line out of the threaded connection port. That line will bend ever so slightly and you'll never get a great and perfect threaded fit when putting it back together (again having to wiggle the connection into place).

Lift and reset the carb away from and back onto, the fuel line. That said, order two new base gaskets. Seems like a lot of trouble but I have cross-threaded more than once (practically irreparable) in this very scenario. Will take maybe an extra 5 minutes total and well worth the patience. Do not ask about a torque spec.. :D Tighten only to snug tight to seal the gasket.

$0.02

.

I always say nothing tighter than a good cross-thread, but they will tend to leak a little fuel.

Good advice. :toast:

strad
03-13-2013, 08:58 PM
Well of course nothing is as easy as it is supposed to be. The fuel line fitting appears to be seized to the carb adapter, and the other end (down at the pump) the fitting is seized to the fuel pipe (but fortunately not seized to the fuel pump fitting). So turning the fitting turns the whole fuel pipe lol. Damn.

I think I just may lift that carb off the manifold before this is done lol. Might have to replace the fuel pipe and the adapter as well as the offending gasket.

Cloaked
03-13-2013, 09:08 PM
Well of course nothing is as easy as it is supposed to be. The fuel line fitting appears to be seized to the carb adapter, and the other end (down at the pump) the fitting is seized to the fuel pipe (but fortunately not seized to the fuel pump fitting). So turning the fitting turns the whole fuel pipe lol. Damn.

I think I just may lift that carb off the manifold before this is done lol. Might have to replace the fuel pipe and the adapter as well as the offending gasket.The original fuel line is hard to find. Not that a marine grade hose is not beyond a mitigation strategy but it is not recommended. Be patient with the line until you decide you may very well not find a replacement and trash it out (or not). Discount Inboard Marine advises that they do not have the OEM metal fuel lines.

. You may also have luck with a penetrant, but the trick is to get gravity to work in your favor (on the carb end).

I will say this as a last resort: Seeing you have an 84 model and if that is the original carb.... ahhhhhhhhhhhh never mind.... Not a good approach as a cop out to an issue.... new carbs are darn near $600.....

Most of all, be patient and don't get frustrated with the carb. Been there too and after a lot of years, I have come to know patience with a 4160 is required. Once the 4160 is working great, it is a good performer....

.

strad
03-13-2013, 09:53 PM
Well I could not get the lower end to separate from the fitting and turn. Destroyed that end of the pipe trying to get them to go. I did soak it with penetrating oil for awhile first too. So I will have to find the new pipe or have one made. skidim's web site has the part on it? No information listed that they do not have it? I will call them tomorrow. I was able to get the other end undone once it was off the carb, so I can save that expensive brass fitting.

east tx skier
03-13-2013, 10:16 PM
Sorry it seems to be irreparable. Often times, leaks at that point are the result of overtightening. I don't recall the torque specs, but if you really crank it down, it will leak.

ski_king
03-13-2013, 10:50 PM
I had a similar problem once. I ended up replacing the fitting that screws into the carb, the fuel line and the gasket. All available from discount inboard marine.

But as Doug said. If it has been over tightened, you may be screwed.

strad
03-13-2013, 11:57 PM
Well I am screwed now as far as the fuel pipe goes lol. Threads on the pump fitting and on the carb adapter look good though. So I need a fuel pipe, the adapter gasket and the two base gaskets for the carb. Hope skidim can hook me up!

thatsmrmastercraft
03-14-2013, 01:47 AM
Bending a new metal fuel line isn't that difficult. If you don't want to tackle it yourself, you can always go with the stainless option from SKIDIM.

http://www.skidim.com/products.asp?dept=1117&val=0&pagenumber=2

http://www.harborfreight.com/tubing-bender-3755.html

east tx skier
03-14-2013, 10:41 AM
I had a similar problem once. I ended up replacing the fitting that screws into the carb, the fuel line and the gasket. All available from discount inboard marine.

But as Doug said. If it has been over tightened, you may be screwed.

If it has been overtightened (and not crossthreaded), you can just back it off and retorque.

thatsmrmastercraft
03-14-2013, 10:53 AM
If it has been overtightened (and not crossthreaded), you can just back it off and retorque.

Over-tightening will likely leave the gasket in need of replacement.

strad
03-14-2013, 12:31 PM
Well I just did the order. Everything was in stock. I'm doing water hoses too. Should make the engine look a little better!

thatsmrmastercraft
03-14-2013, 12:51 PM
Well I just did the order. Everything was in stock. I'm doing water hoses too. Should make the engine look a little better!

Where do you go boating in Vegas? Lake Mead?

strad
03-14-2013, 01:03 PM
Yes. Any wind at all and it gets real choppy real fast. I've noticed that the narrows area (if you look at a chart you can see where this is) stays smooth more than other areas. This will be the first full summer we've had the boat. Should be fun.

thatsmrmastercraft
03-14-2013, 01:06 PM
Yes. Any wind at all and it gets real choppy real fast. I've noticed that the narrows area (if you look at a chart you can see where this is) stays smooth more than other areas. This will be the first full summer we've had the boat. Should be fun.

My son lives in Vegas and says it is always windy. I assume early and late will be the standard for calm water. As I recall there is a little more protection in the narrows area from what I remember from the aerial view. Enjoy!

east tx skier
03-15-2013, 12:35 AM
Over-tightening will likely leave the gasket in need of replacement.

Maybe I was lucky. But when I had a peak on my 93, my local Correct Craft mechanic just backed off the nut and retightened it. Never another leak, and I doubt of the new owner has had one. Anecdotal, perhaps. But I would try it before replacing the gasket.

thatsmrmastercraft
03-15-2013, 12:41 AM
Maybe I was lucky. But when I had a peak on my 93, my local Correct Craft mechanic just backed off the nut and retightened it. Never another leak, and I doubt of the new owner has had one. Anecdotal, perhaps. But I would try it before replacing the gasket.

The simple fix is often-times the best approach. I have seen many of these gaskets as coated washers (brass?) and if that the case here, backing off a little would likely do the trick.

east tx skier
03-15-2013, 12:54 AM
It was a replacement carb and fuel line (back when they still offered them) from skidim. Not sure what was in there. All I know is that it too him 10 seconds, and I wasn't charged a dime.

thatsmrmastercraft
03-15-2013, 12:56 AM
It was a replacement carb and fuel line (back when they still offered them) from skidim. Not sure what was in there. All I know is that it too him 10 seconds, and I wasn't charged a dime.

Hard to find a way to complain about that.

strad
03-15-2013, 12:52 PM
Well that would have worked in my case, but everything seemed so seized together that I couldn't safely loosen some of the parts enough to try tightening the offending fitting. The leaking fitting was definitely loose and If I could have gotten the fuel line loose from it I would have been in business.

thatsmrmastercraft
03-15-2013, 02:05 PM
Well that would have worked in my case, but everything seemed so seized together that I couldn't safely loosen some of the parts enough to try tightening the offending fitting. The leaking fitting was definitely loose and If I could have gotten the fuel line loose from it I would have been in business.

Not an uncommon problem to have a steel line stuck to a fitting. Have had to deal with this more many times.

strad
03-22-2013, 06:45 PM
Back in business. Fuel line arrived packaged in "genuine PCM" packaging. Installed line, adapter gasket, scraped old gasket off carb, spacer and intake manifold. Slapped carb down, tightened everything up snug. Next morning pulled boat out and made sure it runs. It does -- took a few seconds to refill the carb with fuel before it fired though. And no fuel leaks. Yay! Just in time for spring break lol.