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Engine won't start


Mark / Brenda

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My R100rt won't start. I went out to the garage and turned the key on and the fuel punp made a grinding sound. I turned it off and then on and the fuel pump did it's normal 10-15 second run up. At first It would fire on one cylinder for one hit and then nothing. Now it won't even do that. I pulled the spark plugs and I have spark but the plugs are dry. The fuel pump still does its normal 10-15 second run up but will not even try to start.

Bad fuel pump, plugged fuel line or bad injectors?

 

Any suggestions on where to start?

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The normal pump on time after you turn the key on is 1-5 seconds, right?

 

It may be that you have a ruptured in-tank hose. The best way to test that is to measure fuel flow in the return line sending fuel back to the tank. Can you do that? The test will tell you if a sufficient quantity of fuel is getting to the injectors.

Edited by roger 04 rt
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I will try that . When i thnk about it, 10-15 seconds is a long time. 5 seconds sounds a little more accurate-sorry . I have a pressure gauge , I'll try this afternoon .

 

Will let you know the results

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You don have to use a pressure gauge. Remove the RETURN hose (upper hose) near the right throttle body and plug the hose going to the tank so it doesn't leak. Then see if you get a good surge of fuel coming out the plastic line at key on. If you do, you've got pressure and enough volume to start.

Edited by roger 04 rt
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Good Morning Mark/Brenda,

Pull the tank off and remove the access cover and pull the fuel pump assy. out and check the U shaped hose.I have had them go bad before, it's a simple job and then you will know for sure weather or not it has a crack in it. The fuel that we burn with the 10% alcohol in is pure garbage to our bikes.

The reason I say this is last year I had one go bad in my tank and I tried this and that with no success. When I removed the fuel pump assy. There it was a cracked U hose, replaced it and I was up and running.

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  • 9 months later...
Mark / Brenda

I'm back!!!!! I pulled my tank back off and put all new hoses in the tank. I put the tank back on and pulled my return line off. When I turn my key on, I still hear my fuel pump start for a second or two and stop but no fuel comes out the return. Could there be a check valve that stuck and will not let fuel by. I hate to buy a new fuel pump since I hear it pump or is pretending that it is pumping. A plugged fuel line? A plugged fuel filter? My bike hasn't made it out of the garage since last year.

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I'm back!!!!! I pulled my tank back off and put all new hoses in the tank. I put the tank back on and pulled my return line off. When I turn my key on, I still hear my fuel pump start for a second or two and stop but no fuel comes out the return. Could there be a check valve that stuck and will not let fuel by. I hate to buy a new fuel pump since I hear it pump or is pretending that it is pumping. A plugged fuel line? A plugged fuel filter? My bike hasn't made it out of the garage since last year.

 

Afternoon Mark

 

 

Not really a check valve but the fuel pressure regulator has an internal spring loaded valve.

 

See if you get any fuel out of the pressure side of the system (pressure hose coming from tank to rear of bike), if you do then hold your finger lightly over the hose end & see if will make any pressure. (40+ psi should be difficult to hold back with a finger)

 

I have seen a few fuel pumps where the plastic impeller will free spin in the motor shaft giving a pump run sound but no pumping.

 

 

 

 

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What kind of hose clamps were used inside the tank?? I had a screw type clamp that wasn't quite tight enough let the hose pop off shortly after the install. Motor no run.

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Mark / Brenda

I will try checking the pressure side.

 

I started using the clamp style that you crimp on

 

Thanks for the help guys, I will try working on it tonight.

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I will try checking the pressure side.

 

I started using the clamp style that you crimp on

 

Thanks for the help guys, I will try working on it tonight.

 

Evening Mark

 

Another thought on your problem-- Did you have any wiring off (removed from) the fuel pump? If so any chance that you have it wired (reconnected) backwards? If the pump polarity is reversed it will still run but not make any pressure. (this should show up in your pressure side test)

 

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  • 3 weeks later...
Mark / Brenda

Just a "Thank You" to all of you that gave me a hand with my fuel problem.

 

Turned out it was my fuel pump. Runs like a champ.

 

Ordered my pump from Beemer boneyard.. Sent them an email on a Sunday night, answered me the same night. Ordered my pump on Monday and had it on Thursday using regular mail. There can't be a better company out there. Every time, they impress me.

 

Thanks again for all your help everyone, I hope I can reciprocate in the future.

 

 

mark

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