View Full Version : Fixing fuel lines


OakIsland
07-19-2004, 07:04 PM
I had taken off the cover of my Craftsman chainsaw and had trouble
putting it back on. When I removed the cover, bits of fuel line
were loose or fell out. Seems I pinched it somehow.

My questions for you:
- Where should the fuel lines go?
- Will any ol' tube work or do I have to special order it?
(I suspect it needs to be a snug fit and that I might have
to lightly round the end to get it into the hole in the
fuel tank, or something like that)
- I'm curious to know, if anyone has the time for this
extra-credit item: how do these separate fuel line
pieces "work" in supplying the engine with gas "at all
angles?"


I have taken pictures so that I can describe to you what I saw
before the bits fell out.

View 1 http://www.phoons.com/john/download/motorview1.jpg

At the left is the almost-intact main line from the tank
to somewhere on top of the chainsaw.

The curved fragment had its left end in a hole atop the
black tank. Its right end headed toward the electrical
connector. I didn't think about that until after the
curved fragment fell out.

The straight fragment was laying along the right, between
the electrical connector and below the rear screw hole.
(It seemed wedge in, so I'm concluding that that was its
original location. I can't see any holes into which that
tube would fit, so I'm concluding one end of the tube
was open.)

I'm *guessing* that the two fragments were once a single
tube which was squished between the electrical connector
and the black tank...and broke at that location due to
age and my pushing on that tube when remounting the cover.


Drawing http://www.phoons.com/john/download/motordrawing1.jpg

This illustrates my *guess* at where tube 2 was and
shoudl go. But I have no idea why the tube would be
routed under the electrical connector (since that would
squish it) nor why tube 2 would have a long taper cut
at end 2B.

Additional views:

View 2 http://www.phoons.com/john/download/motorview2.jpg
View 3 http://www.phoons.com/john/download/motorview3.jpg

Thanks, John

hankster
07-19-2004, 08:42 PM
What model chain saw is it? There are so many models and so many ways the fuel lines can run that it is almost impossible to say without the model.

My guess is the fuels lines were just plain dried out and shot. Normally they are flexable and shouldn't "break". Any small engine repair shop should be able to sell you a foot or two of fuel line. Also, with the fuel line being this bad, most likely a bunch of gunk got into your carb. You'll most likely have to remove it and clean it. Also check the filter in the tank... might as well replace it since you are going to have run all new fuel lines.

OakIsland
07-20-2004, 02:49 PM
> what model is it?

Craftsman 358 356081. I tried searching for this on the 'net and didn't find matches... but I found you! Thanks :)

Regarding how the lines are routed, would you *guess* that my drawing is correct--specifically where tubes 1 and 2 connect at the A and B holes?
http://www.phoons.com/john/download/motordrawing1.jpg
It sure looked to me like the tubes did not extend very far into the tank through those holes....or *should* they extend deep into it? (and I might have long chunks of tube in the tank now?)

> fuels lines were probably just plain dried out

Agreed.

> shop should be able to sell you a foot or two of fuel line
> likely a bunch of gunk got into your carb / remove / clean
> check the filter in the tank

Sounds good.

John

hankster
07-20-2004, 03:19 PM
Let me look up that model tommorow at work and I can give you more details (hopefully).

One line is the supply line, it will extend into the tank a few inches and have a filter on the end.

The other is the return line. It only goes into the tank maybe an inch.

Try this. Go to www.sears.com and click on the Parts link on the upper left side of the page. On this next page search for model number 358.356081 (search is in the upper left side of the page). You'll get one item, click continue. Now View Diagram for the Main Frame. That may give you an better idea of what is needed and where it goes. This is basically the same diagram I would work off of.

OakIsland
07-21-2004, 04:05 AM
> supply line... extends into the tank a few inches and has a filter on the end

Oh great... so mine's definitely disconnected from the filter, huh! I have not yet looked to see how the tank is mounted or how I'd be able to get at the filter, but it's do-able.

> The other is the return line. It only goes into the tank maybe an inch.

Okay. But "return line" makes me think "a complete loop"....and the end that I labelled 2B in my drawing appeared to not go into another hole. I figured it was completely loose by design. It would make more sense to me that it should continue on through some hole in the upper wall and connect to something else, but I haven't seen that connection place. Could you please suggest what I look for regarding the currently-tapered end of my tube?

> Go to www.sears.com and click on the Parts link on the upper left side of the page. On this next page search for model number 358.356081

Thanks for the great link. Funny: the fuel line next to number 22 in their diagram has a top end that goes...where??

You mentioned a filter. They have #20, "FUEL PICK-UP ASS'Y." Are these one and the same? And something I should be able to pick out of the fuel tank through the port I pour fuel in? Interesting.

Thanks,
John

hankster
07-21-2004, 03:23 PM
Let me get you some Sears part numbers for fuel line and a filter tomorrow. Total cost is about $5. I looked up the saw and we have the same diagram as what is on their web site. Since that saw doesn't have a primer the lines go straight from the carb to the tank... nothing in between.

The fuel line will push into the hole on the tank and is big enough to seal the hole so fuel won't leak out. I just cut the end at an angle and push it through the hole in the tank, use some needle nose plyers to grab it through the filler hole and pull it far enough to cut the end straight and push on the filter.

The return line also just pushes through the hole an inch or so. There will sometimes be a small fitting that you put on the end of the line inside the tank to make sure it doesn't pull back out but normally if you just leave an inch or two inside the tank, it won't come back out.

chadkt
08-01-2004, 01:25 AM
I have a similar problem with a 1980s sears craftsman chainsaw model 358.355061. The sears.com parts link is under repair. The fuel line is broken up. I bought a new line and air filter, and am about to put it together, BUT cannot find out where the fuel line goes into the gas tank. Unlike the above post, there is only 1 hole in the tank near the gas cap, about 1/16-1/32" in diameter. I found a fuel filter with partial fuel line attached in the tank and assume it should be there. Any thoughts?

chadkt
08-07-2004, 09:29 PM
I thought the gas tank hole was 1/16-1/32" in diameter. Upon closer examination, the old fuel line was cracked off making the hole look too small. So I fixed the fuel line, followed the diagrams and the saw works great. Thanks. :cool:

iimagine
10-09-2004, 10:38 AM
I have a simular question regarding the routing of fuel lines. My Dad's saw is a Craftsman model 358.351080 and I checked the Sears site out before I found Ya'll but the diagrams arn't specific enough. I replaced the fuel lines but like an idiot I didn't draw myself a routing diagram. My question: As your looking down on the saw from the back does the fuel line with the filter, coming up from the tank go to the right-side port on the carb(basically, fuel flows from right to left through the carb to the priming bulb)?
Thanks!
iimagine

iimagine
10-26-2004, 05:22 AM
Bump.
Anybody know?

hankster
10-26-2004, 03:08 PM
Let me see if I can find a like model tomorrow at work and I'll let you know.

hankster
10-28-2004, 10:34 PM
The small line goes into the tank and has the filter attached. The other end of the small line goes to the inlet side of the carb. The larger line goes from the outlet side of the carb to the primer and then a larger line from the primer to the tank. When you press the primer it should suck fuel from the filter in the tank, thru the carb, thru the primer and back to the tank.

Smalblok355
11-03-2004, 10:36 PM
i use to work for Sears..........thats a normal problem with all craftsmen chainsaws,and even the weedwhackers too....after about a 1 year the fuel lines went bad on them...............best bet is to take it back to Seras and get it replaced with a brand new one...............

rwing21
09-09-2006, 02:26 PM
Let me get you some Sears part numbers for fuel line and a filter tomorrow. Total cost is about $5. I looked up the saw and we have the same diagram as what is on their web site. Since that saw doesn't have a primer the lines go straight from the carb to the tank... nothing in between.

The fuel line will push into the hole on the tank and is big enough to seal the hole so fuel won't leak out. I just cut the end at an angle and push it through the hole in the tank, use some needle nose plyers to grab it through the filler hole and pull it far enough to cut the end straight and push on the filter.

The return line also just pushes through the hole an inch or so. There will sometimes be a small fitting that you put on the end of the line inside the tank to make sure it doesn't pull back out but normally if you just leave an inch or two inside the tank, it won't come back out.

4 years later and the same problem. New user though. Where does the return line terminate at.

Thanks in advance.

hankster
09-09-2006, 09:52 PM
Inside the tank.

rwing21
09-09-2006, 11:18 PM
Inside the tank.

inside the tank to what is the magic question. I do not have a primer bulb. One of my friends suggested that maybe it is a vent.

hankster
09-09-2006, 11:56 PM
It just goes inside the tank and is open. It is a "fuel" return line to return excess fuel to the tank.

rwing21
09-10-2006, 11:23 AM
It just goes inside the tank and is open. It is a "fuel" return line to return excess fuel to the tank.

Thanks for the responses.

I underdstand that it goes inside the tank. From the tank, where does it go. There is no other place that I can see to attach it to (ie carb/primer bulb). To be a return line, it would have to connect to the carb or some where else wouldn't it?

Yesterday, I hooked up the small line to the carb. I left the larger line going into the tank and terminating no where. As expected, fuel came out of the line as I attempted to start it.

Thanks again for your help!!

hankster
09-10-2006, 11:29 AM
Sorry, didn't read close enough. I see your carb only has one connection then? If so, there is no return line and not sure why the tank has a place for one. Maybe we should start out by asking what make and model you are trying to fix.

rwing21
09-10-2006, 02:56 PM
Not a problem. It is a Sears Craftsman. Model# 358.356081. Made somewhere in the 80's.

rwing21
09-13-2006, 10:54 AM
Any ideas Hankster?

EJW305
09-23-2006, 09:17 AM
I am new to this Forum, I have a Sears 3.7 chainsaw from the late 70's early 80's, I am having the same prob as RWING 21 I cant figure out where that line should terminate. I did the same thin left it hanging out there and all it di was piss fuel out. Help Please

rwing21
09-28-2006, 02:46 PM
If I find out anything about it I will post it here. This thing is driving me crazy. I have had several people look at this thing and they do not have clue either. I guess the next step is to take it to Chainsaw World and see if they can figure it out.

30yearTech
09-28-2006, 03:19 PM
The model number discussed above looks like an old Poulan 3400/3700 series chainsaw. The second hole was for a fuel tank vent. All that it amounted to was a small piece of fuel line with a duckbill check valve on the end of the hose inside the tank. I don't know why but this is not shown on any of the IPL's I could find, but I worked on alot of these saws in the late 70's early 80's they were a very popular model. I am not sure but I also think that they may have had a small screw threaded into the vent line at the other end.

EJW305
09-29-2006, 08:23 AM
I went and got a new duckbill valve that fixed it leaking and I just out a little piece of fuel line on the end and tucked it between the switch wire ands the tank. Saw runs fine. I also just picked up a Craftsman 55cc 20in Bar from sears anybody try one of these yet?