Vapor Locked
- Thread starter Goatkart
- Start date
yea, if it's sitting on the breather you need to raise it up and get it off that heat source. moving the pump to an alternate location is he best remedy. You can wrap it in insulation but that's just a bandaid.
In tank ? Good luck with it.
texas-buzzard
Registered
Had the same problem. finally relocated it behind the crankcase below the trailing arm and no problems anymore with VL.
I considered the subframe location.... but eyeballing it, it seemed like that was above the lowest part of the gas tank?
My swing arm has the over bracing removed, and i am running only underbracing, so i SHOULD have space...
Was also eyeballing this spot as well....
Are you both then putting the fuel filter also outside of the undertank location? I assume the tail mounted location is just because of the distance...
Just trying to find the best location for a do it once, and for good scenerio..
Aaron, the RCC fuel pumps are surrounded by a thick rubber sleeve, and are not usually a problem. It is more likely that your fuel filter - which is metal - is the culprit. Make sure it is not sitting on the engine where it can absorb heat . . .
Goatkart what is 'vapor lock' and how does it affect a turbo bike?
Just curious?
Just curious?
I was kinda thinking the same thing after scratching my head for awhile... I had been getting a whistle from the regulator which i also heard from crawling forums was symptomatic of the fuel filter boiling some gas.. i caught a thread where richard aparently told someone who told someone... so who knows if its true..
The fuel filter isnt laying on anything... i dont think... however, thats not to say when the tank is laying down, it doesnt then...
It seems like it gets bad when i take extended trips at 70-80mph... 30 minutes or more, then i get to some intown driving and the fuel pressure falls off to 36-38 lbs...
I've considered insulating that fuel filter somehow i just dont know exactly how...
Open to suggestions for sure!
Basicallly, the fuel pump, or fuel filter, or something... Gets hot enough that it actually boils the fuel in the fuel lines...
This creates a gas bubble....
Now the pump which is gravity fed, cant pump a gas only liquids, so suddenly fuel pressure takes a dive...
Also, causes a problem when it comes to priming the fuel pump for startup, as the gas bubble prevents fuel from getting to the pump, allowing the pump to prime, as heat soak can make the problem even worse until it cools off..
texas-buzzard
Registered
I tried wrapping and suspending the pump, fuel filter and hoses but the problem lived on. i could actually see the gas bubbles in the clear filter. by mounting the pump low the bubbles now travel up to the tank allowing the pump to receive fuel. the fuel bubbles still form after a long hot ride but never get to the pump. after the engine starts cool fuel from the tank eliminates the heat build-up in the lines. someone told me that the ethanol based fuel we use lowers the boiling temp.
I insulated mine with a couple neoprene can coozies and then wrapped them in some silver adhesive heat shield.
Thanks for the explanation.
With gas boiling is there any chance of explosion?
With gas boiling is there any chance of explosion?
texas-buzzard
Registered
not any more than the vapor in the fuel tank. it would need a spark which is highly unlikely in that enviroment. vapor lock was quite common back when vehicals used carbs but high pressure fuel injection elimated it. the vapor problem on our bikes form on the inlet ( low pressure ) side usually when the bike sits after a hot run.
