I knew what I was getting myself into with a 13 year old bike, and it's not letting me down.

When I fired it up yesterday, started getting a drip of gas, which went away after a minute.

Same again when I fired it up to go home, only a little more pronounced.



The issue appears to be that gasoline, over time, eats O-rings, and the one at part #11 on the rear hose (return fuel line) in the diagram above has given up the ghost - for some reason, it appears that one usually goes first on FLHR models.

So, the plan is to depressurise the fuel system, throw a funnel under the fitment to drain any gas that leaks into a fuel can, back the fitment out and pull the o-ring, then replace - will probably do the same for the forward (fuel delivery line) at the same time. Fairly straightforward, but I have a few questions...

Question 1 - I'm tossing around the idea if throwing some thread sealant on the fitment threads when I slap it back together. Good idea? Bad idea?

Question 2 - Standard hardware store plumbing o-ring made of the same material as the Official Harley Part?

Question 3 - The nut for the fitment won't take a socket, but is meant to be torqued to 20-24 nm - how do you accurately get torque measurement on an open end wrench? All I can think of is hooking a spring scale through the box-end to measure the force on the wrench. Any advice?

 

Q1 - can't do any harm!
Q2 - the trouble with O rings is they are almost all black, which might suggest they are all made of the same stuff, however there is a wide variety of rubbers available and I wouldn't fit a universal O ring in place of a 'real' one, except in an emergency, or unless it is made for use with gas. Get a Harley one and be sure!
Q3 - you can either buy a 'crows foot socket wrench', which can be used with a torque wrench, or simply tighten it with care!

 

Thanks - especially for the crow's foot wrench advice, had never seen those before, but found a shop near home that sells them, will have a set in hand, hopefully tomorrow. Any time I get to add a new tool to my collection instead of paying the dealership I'm a happy man.

Sure beats measuring the offset on a standard wrench and pulling on the end with a fishing scale to get the torque down!

 

I only discovered them about a year ago! I have one for my exhaust pipe nuts on the heads, so happy to share.

I've tried that in the past.....

 

Be sure the crows foot is at 90* to the torque wrench or you will get a higher torque than the wrench reading.

Or divide the total length of the wrench and the extension into the length of the torque wrench.

Multiply that number by the given torque value and use the answer as the torque to apply.

 

Generally a combination wrench the correct size will give the correct torque for the connection. Unless you are a wrist wrestler. It's when you use a socket on a ratchet is when things get tricky as you are using a set leverage with different socket sizes on connections that require different tq values. This is also assuming steel nuts and bolts. TQ values without a gasket compression are just a standard tight but don't overdo it tq value.

 

Thanks for that, I would have assumed to just use 'em straight on.

 

Well hell. Turns out it isn't the o-ring - pulled it and it was in perfect shape. Put everything back together and now the leak is a little more apparent - it's being pushed back out through the actual fitment.



Looking at the diagrams it's either the return line assembly (#28) blown, or the return fuel check valve sticking.

As it stopped leaking before after running a little, I'm thinking it's more likely the check valve (#26) sticking, which with the bike sitting for a number of months before I got my hands on it wouldn't be any great surprise.

I think the smart move at this point is to replace the return check valve and return fuel line assembly since it gets rid of some 13 year old rubber, and do the supply side ones as well while I have the tank off since removing an FLHR tank is a bitch and a half.

 

Oh, and is it wrong that I'm almost as happy wrenching on it as I am riding it?

 

nothing is wrong with enojoying wrenching on it, to me thats half the fun. getting frusterated and then the eventual happiness of success. half the problem with leaking o-rings, and fuel delivery problems these days are becuase of the Sh*T fuel the government has worked so hard to f*ck up for us. Ethanol eats certain rubbers, and in some cases the plastic floats in carb bowls (had a sidedraft weber 40 DCOE that recently did that) as well as eating your fuel delivery system you also get the wonderful added benefit of the Alchohol in ethanol breaking down over time and gumming up your carbs and other small passages, like say, a check valve. it also attracts water to it so if your bike sits for any length of time its good to drain your tank, Period! im sure its been talked to death on every motor head forum ever but you also lose fuel effieciency and horsepower with ethanol blend fuels...
not to get political on everyone here but if were up to me all these greenies, AL gore and the like should be dragged out and shot just like they would be in the system they all prefer... communism. ok ill get off my soap box now... sorry... NEVER MESS WITH A MANS MOTOR VEHICLES!!!