The dreaded vapor lock

Forum rules
Please start new topics here: New Panhead and Flathead topics
Post Reply
Sidecar
Member
Posts: 293
Joined: Sat Sep 14, 2002 8:54 am
Bikes: -
Location: Southwestern, Pa.
Been thanked: 1 time

The dreaded vapor lock

#1

Post by Sidecar »

I made my own fuel line from 1/4 in. ID aluminum aircraft fuel/oil line. Looking at it while sitting on the seat it runs parallel along the bottom of the left tank (I have the old style tanks with the shut off knob on the top of the tank, near the filler cap) and then down thru the cylinders, at a 45 degree angle, to the bottom of the Super E. It was working just fine until the ambient temp. rose over 80 degrees. It's ok until you have to ride slow for a period of time. I was kinda bummed out because it was a nice clean installation. I'm going to try a length of Stainless tube before doing something else.
I think a PVC coated aluminum tube would have worked just fine.
No use ramblin' on anymore.

Ride safe ya'll !!!!
mbskeam
Senior Member
Posts: 1014
Joined: Fri Apr 18, 2003 12:26 pm
Bikes: *
Location: Sultan, WASH
Been thanked: 6 times
Contact:

Re: The dreaded vapor lock

#2

Post by mbskeam »

hello, I see that im not the only one to have this happen to. mine involved a alum. fuel filter that replaced my glass one that broke." in the garage", does that really happen? the motor only had about 10 miles on it . so as im runing, it gets kinda warm on the clys. with it all nice and tight. and not broke in. stoped at the store and got to kick it for 30 min or so. trying diff. things. finally pulled feul line and spit, sputer, spit , out came the air. it then started. man my leg was sore the next day as it now has compression. on both cyl.it tryed a few more times to do this little trick to me but I've caught it before it would do the evil.with 500 on it now it seems to be okay as it is runnig cooler.
mbskeam
King
Inactive member
Member
Posts: 400
Joined: Mon Jan 27, 2003 1:25 pm
Bikes: *
Been thanked: 4 times

Re: The dreaded vapor lock

#3

Post by King »

Iv'e been having problems in that area too. I'll be motoring along and suddently get the sputters and she will shut down. First time it happened I did a lot of head scratching but after I opened my left (unvented) gas cap and heard a bit of a gurgle she started right up. Since then I vented the left cap but occassionally it still happens and I just twist off the cap while running and it's OK. The other wierd thing is I have installed the see thru gas filter vertically, just below the inlet to the Bendix, but it rarely gets full of gas. Most times it is only a quarter full. I know Pans can be difficult at times but I never knew they could overcome gravity!!

King
Sidecar
Member
Posts: 293
Joined: Sat Sep 14, 2002 8:54 am
Bikes: -
Location: Southwestern, Pa.
Been thanked: 1 time

Re: The dreaded vapor lock

#4

Post by Sidecar »

I guess that I would have to say that I'm sorry to see that others are having the problem.
The aluminum under the tank is ok, but if you touch it down at the bottom of the "E", it's REAL hot.
I'm going to put rubber line back on it til I can get the stainless bent.
I'm going to try to find some plastic coating for the new fuel line before I install it.

UPDATE

I tried using plastic wire loom on the Aluminum fuel line with no success. I put the right size wire loom over the line and installed another larger size directly over the smaller one. Still gets too friggin hot !!!!
The heat must be from the dead air space between the 2 cylinders ??
It sure takes a long time to "cool the fuel" after it vapor locks..........
I'm going to have to spend some time looking at alternative installations !!!!
I'm still bummed out !!!
Jack_Hester
Inactive member
Member
Posts: 460
Joined: Wed Apr 09, 2003 2:05 pm
Location: Roxboro, NC, U.S.A.
Been thanked: 4 times
Contact:

Re: The dreaded vapor lock

#5

Post by Jack_Hester »

Sidecar -

Make yourself an insulator out of a piece of thick rubber oil line, split lengthwise, and slipped over the section going between the cylinders. See if that works.

Jack
Post Reply

Return to “Carburetor/Fuel system”