Author Topic: Question for Royal Enfield 1  (Read 3983 times)

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hutch

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on: January 07, 2009, 07:42:02 pm
Kevin, something has come to my attention that I need to ask you about. I am hoping that it has been thought of by RE. A couple of other bike manufactureres have run into a problem with Fuel injection models. Moto Guzzi went to fuel injection and had the following problem. The fuel pump is located in the gas tank and is continualy submerged in gasoline. I don't know if the RE is that way or not. With the new fuels having methanol in their mix, they ran into the problem of the hose in the tank swelling up, because of the methanol,and being forced off the fuel pump by built up pressure. This causes the bike to run out of gas when the tank has all kinds of fuel in it. They had to go back and replace the originally used hose with high quality hose. I know RE has not got the best reputation for it's rubber products on their bikes.because of cracking and getting hard and brittle. Do you know if RE is using the same hose as on the old bikes? It could come back to bite them in the butt if it has not been thought of and cost them a lot of money for recalls and replacement. I was just wondering about it.  I have heard of other companies having the same problem on their bikes when they switched to EFI ,for the same reason. The problem seems to show up after quite a while, and sometimes after the warranty is up, but it is something to think or ask about.Hutch
« Last Edit: January 07, 2009, 07:49:26 pm by hutch »
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ace.cafe

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Reply #1 on: January 07, 2009, 08:11:24 pm
It's a good question.

I know that this new formulation of gasoline with the ethanol is eating the heck out of my manifold rubbers. They don't last long.
I hope they are using a solid connection, and not a rubber hose.
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HRAB

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Reply #2 on: January 08, 2009, 12:48:49 am
The prototype bike has the fuel injected into the metal "manifold" at the cylinder head. There is a rubber hose between the airflow sensor and the manifold, but is should only have contact with air. Picture 2008 USC\Pic1252.jpg attached below.

The fuel pump is mounted outside the tank in the position the petcock once served.

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Reply #3 on: January 08, 2009, 04:25:42 am
Funny you should mention Moto Guzzi.  On my first test ride the hose inside the tank DID come off and I was lucky to coast off the freeway ramp to a side street.  Back to the shop via pickup, the problem was quickly diagnosed (they'd seen it before...).  The hose clamp was changed from the cheesy pinch clamp to the screw in type most of us are used to.

Anyway, I didn't buy THAT particular unit.  The Nevada I bought was equipped with proper hose clamp and the problem is fixed (at least for the first 3k miles). 

So it wasn't the rubber per se, but the clamp.


hutch

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Reply #4 on: January 08, 2009, 02:46:07 pm
The prototype bike has the fuel injected into the metal "manifold" at the cylinder head. There is a rubber hose between the airflow sensor and the manifold, but is should only have contact with air. Picture 2008 USC\Pic1252.jpg attached below.

The fuel pump is mounted outside the tank in the position the petcock once served.

All is well.
Jim


HRAB thanks for the quick reply. I am glad that RE put the fuel pump on the exterior of the tank. Sometimes I wonder where engineers come up with some of the things that make it out to the public. Things like having to drop gas tanks in cars to change fuel pumps that are in the tank. I used to put a Stewart Warner electric fuel pump at the back of my race car to push gas through a 3/8 fuel line, but it was mounted to the frame. I do believe some of these ideas are to make money on repair costs. Thanks again.  Hutch
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Vince

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Reply #5 on: January 08, 2009, 06:05:57 pm
     A lot of design choices are made with criteria we don't see. Hutch, I once asked a friend in the automotive repair business about the fuel pump in the tank. His answer was that there it is constantly cooled and lubed buy the gas, and is not subject to potential cavitation issues the way an engine mounted pump would be. So the benefits are much longer pump life and more consistent fuel delivery. A repair would cost more, but would be less frequent.  His one caveat was that I needed to keep the tank at least 1/4 full to glean these benefits. Consistently running the tank lower would shorten pump life.
     With the new RE pump having a direct and constant  gravity feed and cooling air flow around it I thin pump life should be excellent.