The dreaded vapor lock

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Sidecar
Posts: 248
Joined: Tue Apr 17, 2007 9:21 pm
Location: Southwestern, Pa.

The dreaded vapor lock

#1

Post by Sidecar » Wed Jun 09, 2004 12:58 pm

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
Posts: 964
Joined: Tue Mar 16, 2004 5:52 am
Location: Sultan, WASH
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Re: The dreaded vapor lock

#2

Post by mbskeam » Thu Jun 10, 2004 5:12 am

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
Posts: 373
Joined: Fri Apr 02, 2004 5:05 pm

Re: The dreaded vapor lock

#3

Post by King » Thu Jun 10, 2004 9:11 am

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
Posts: 248
Joined: Tue Apr 17, 2007 9:21 pm
Location: Southwestern, Pa.

Re: The dreaded vapor lock

#4

Post by Sidecar » Fri Jun 11, 2004 1:33 pm

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
Posts: 414
Joined: Sat Sep 18, 2004 7:21 pm
Location: Roxboro, NC, U.S.A.
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Re: The dreaded vapor lock

#5

Post by Jack_Hester » Fri Jun 18, 2004 12:18 am

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

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