Sealing Fuel Line Intake - Leaf Blower

I always hesitate to propose solutions to my own problems, but how about these two as a possible means toward a solution:

1) Take a short section of plastic drinking straw (or coffee/cocktail stirrer), split it down the lateral axis, insert it into the inlet hole and then insert the fuel line into the straw insert. The additional diameter that the straw insert provides, may just be enough additional "diameter" to seal the fuel line against the inlet hole wall?

2) In some of my spare parts "junk", I think I have some hard plastic plugs. How about sticking one of those in the inlet hole, and seal it. Then I could either drill a new hole (with a sufficiently small diameter) or drill a hole down the center of the plug (with a sufficienlty small diameter). Then insert the fuel line into the new, now smaller inlet hole.

Maybe either of these will prompt the creative juices to start flowing in the board audience, and some other potential solutions will begin to tumble in.

Try JB Weld, a two part system. You'll have to cut it off later.

http://jbweld.net/index.php

You can buy solvent resistant glues from almost any hardware store. Choose a flexible setting type rather than hard setting type. silicon sealant would probably work just as well provided it is completely "off" before reintroducing the fuel.

From your description it appears the fuel line inserts into the fuel tank rather than the fuel tank having a nipple to connect the line to. I find this most unusual. Is there a part missing or broken off?

1. empty fuel tank and line

2. Allow plenty of time for residue fuel to evaparate.

3 Clean relevant parts with methylated spirits to remove residue oils (i assume 2 stroke fuel is used)

4. Smear small amount of glue onto relevent parts and join. Tip: waiting till the glue has begun to go off a little (but only a little) will give a better seal

5. allow 24 - 48 hours to set.

refill and test seal.

Hmm, okay well first, as far as I can tell, the "in-line" fuel tank inlet isn't missing any parts and actually, I have seen this same configuration on other small 2 stroke engines.

I'm not going to diminish the possibility of the sealing adhesive solution that was proposed, but I'm concerned that since this unit uses a gas/oil mixture, the exterior surface is almost always going to be guaranteed to be at least slightly contaminated, no matter how much you clean the exterior surface. For those reasons, I have a bad feeling that any sealant is going to probably always be compromised, and may not add up to a lasting repair.

Any other suggestions?

No-No-No!

Don't do what all the others and yourself have suggested. Simply get some good quality small nylon Tie-wraps and compress the fuel line around the fuel nipple.

Chumly, There does not appear to be a nipple.

Perhaps its internal somehow or broken off/missing.

Yipes, I have never seen a tank or a carb that did not have a fitting of some kind, sounds like something is fucked up!

CDobyns:

I dont suppose you could post a pic of the relevent area could you?

been there, done that, solved the problem
I've run into the exact same problem. Went to the L&G store with the old fuel line and the parts guy handed me a foot of replacement line. Just eyeballing it was easy to see it was smaller OD. Asked about it and he said that's the right line... Bull!

The answer is not to modify the fuel tank but to get the correct fuel line.

Seems the parts people fall in love with aftermarket suppliers and only want to stock the minimum number of fuel lines instead of the correct sizes.

Had an idea and went to a store that sells RC (remote control) cars... they had "tygon" yellow fuel resistant fuel line in a bunch of IDs and ODs. Matched up exactly what I needed with my old piece and was half the price of the clear vinyl junk that didn't fit from the L&G store.

Wow, that last posting really got the collective juices flowing on this problem.

Again, to the best of my knowledge no external fitting was missing when I bought the unit. I replaced the fuel line (with perhaps the errant OD), because the existing line was too short and kept popping off the carburetor inlet.

The hobby shop fuel line is an intriguing angle to think about working. I'm almost wondering if the angle of just sealing the existing hole and drilling a new smaller diameter inlet hole might not be a winner after all. Obviously I've got a drill and a small drill bit, and I've got my current new fuel line - which isn't exactly working right now.

I can see if I can get a couple of digital photos and host those up. I'll see what I can do to illustrate this better, but my text descriptions have been pretty representative of what the pictures will show.

The hobby shop angle is worth checking out because they seem to understand the need for correct fuel line sizes and stock them. L&G shops are victims of the universal bracket theory of marketing where the bracket works equally poorly in all applications.

I wouldn't modify anything on the tool when the correct fuel line is available.

sorry to labour the point but I've never seen a fuel tank without an external nipple. I find it extraordinary and cant really see how it could have ever sealed properly and not kept falling out or leaking with just a friction seal. I'm certainly not doubting you but just cant help feeling we are missing something somehow.


One thought that occored to me, is the hole into the fuel tank threaded? I'm sure you would have said, so I'm just checking. It might be possible to buy a nipple that could be screwed in to the hole in the fuel tank even if its not already threaded. I assume the tank is plastic so screwing a metal fittin in would create its own thread . With a little teflon gas tape (Yellow I think) It would seal. Look for a propane gas or BBQ grill supplies store. In my small town I'd get that kind of stuff at the hardware store. Possibly even garden watering system fittings might suit.

Similar to this.


Another thought is some kind of missing O ring seal or a compression fitting on the line.

Gasket sealer would probably seal as well even with the 2 stroke oil mix.

Having justalurker post that he had the same problem is comforting. I'd follow up his suggestion of hobby shops. It certainly would be easier just to find the right size tube. Take the unit with you to a few repair and parts sellers so you can try before you buy.

I'd suggest NOT drilling a new hole and sealing the old one. You would need to get the new hole really really smooth to have any chance of a seal. Big risk I'd say, culminating in 2 holes that arn't suitable not just one.

dadpad,

Every weedwacker I've seen uses the same method for the fuel line. A tension seal of the correctly sized fuel line through a hole in the fuel tank.

It does seem odd but it is elegant in it's simplicity with no connections and very reliable. Professionals favor this method as they stock the correct fuel line for their applications and IIRC, Homelite actually specs a specific size fuel line for all their applications.

I just checked my Ryobi weed whacker and it does not follow your method!

For that matter neither does my chainsaw, my RC plane, two gas generators, pressure washer or my three motorcycles. All of them have the usual male nipple and external friction fit tubing!

Now I am not saying that a friction fit internal female fitting does not exist, but I've doodled on small gas engines for 40 years and never seen a friction fit internal female fitting where the gas tube fits into a female hole in the gas tank and is sealed by tube compression.

Also, I cannot imagine why a designer would choose this method over the conventional method with its very-likely higher friction coefficient and thus better-safer sealing.

Please, not my method. Just what I've seen lately on the budget priced wackers and such. My 10 year old Ryobi 4 stroke has fittings and that's what I prefer.



Again, just seen the friction fit on cheaper wackers.



Yup, when they built them like they used to things were done the right way and that Weatherhead fitting selection at the mom and pop hardware store made lots of sales.

Slide on over to Home Depot or Lowes and take a look at the cheap stuff.



Lower cost?

Good points, I love small engines! Although with modern plastic forming I can't imagine there is any real cost savings over the conventional friction fit male nipple, but I'm no designer / cost analyzer.

I'm thinking its a design element. to keep everything tight and tidy under the moulded cover of a domestic sized machine.

Perhaps a "design element" to us is "cutting costs" to the marketing department :wink:

No need to be a designer/cost analyzer...

Eliminating a nipple that costs $.01 over a 100,000 unit production run saves big $$$.

Same as embedding control, sound, video, modem, and NI chips on computer motherboards and eliminating the unique cards previously used to do those jobs.

Lower prices... the market asked for it, they got it, and now we all have to live with the compromises.