Help with a stupid question

I just installed my new IMS seat/Tank (whahoooo!) and I have question about the fuel line. From the petcock, the line runs slightly uphill as it crosses the intake plenum between the head and carb, then downhill as it enters the carb. My assumption is that the weight of the fuel will push the fuel through the short uphill section after the petcock. Am I right? It seems to me that once the line is full of fuel, it should continue to flow, even if there is a section that is slightly uphill. Sorry for the stupid question, but I had to ask. Thanks.

Not so much the weight of the fuel as gravity, syphon, and vacuum forces that will ensure the fuel is going to make it to its destination


As long as the loop up in the hose doesn't go higher than the fuel level in the tank it'll flow.

Don't worry about there being an air pocket in the high spot of the line. I know it looks crazy like you'd need to bleed the air out or something but it works just fine.


MotoGreg - The voice of absurdity

'99 WR400 - 'Cause thumpers rule and two-strokes drool!

'92 GSXR 7/11 (But I wanna get a dope 916)

I might let you visit my photo album for $3 - ENTER AT YOUR OWN RISK - DANGER LURKS WITHIN

When I first intalled my IMS tank, I noticed the gas was not flowing smoothly also. Many air pockets. Drove me nuts. I wanted smooth gas flow damnit. Is that too much to ask for?

I tried routing that line every which way and had no luck clearing the air pockets. Then it hit me, the answer was right there all the time. I just bought a solid black rubber fuel line. I didn't see anymore air pockets :)

Seriously though, I have never had a problem with the gas flow. I run it back of engine over the intake. I will force itself into the carb when the bike is in motion. Laws of physics I guess. But I wouldn't know how, I was a communications major in college.


Dougie, '99 WR400 with a lot of dumb, stupid, here take my money, I have to have them but they don't make me a better rider extra mods.

Thank for the response. As long as the bike doesn't starve for fuel, I'm happy! :)


I have read posts here where guys w/ IMS tanks melted fuel lines on high/tight headers so be careful when you route your fuel line, especially if you have an aftermarket header. You may try zip tying it to head stay to keep it up high.

When I installed IMS on my 426 I went ahead and put a Russel in-line filter since there is now all kinds of room for it what with fuel line going across bike. Filter rests against head stay and carb. Side benefit is it holds fuel line up high and away from my PC T4 header.

Hick, the new IMS tank petcocks have the fuel line exiting toward the rear fo the bike. I have TONS O ROOM between my stock header and fuel line. If I go for an aftermarket header, it will be the PowerBomb. I have not heard of any real conflicts with the IMS and this header.

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