roger 04 rt
New member
It seems every week someone on one Board or another has a suspected fuel system problem. After my system failed last summer I realized that there was a very simple diagnostic point that can check the pump, strainer, filter and in-tank hoses. To test the integrity of the system takes only a couple minutes, after you have the right side plastic off.
The in-tank pump has a capacity at standard pressure of about 120 liters per hour, which is 2 liters per minute. At idle the bike uses very little fuel. Therefore in a good fuel system there is about 2 liters per minute returning from the fuel distributor to the fuel tank.
To make the test you need two feet of hose with a female QD installed on one end and a collection tank. Open the return line QD (upper QD pair on an 1150 RT), plug in the hose and measure the fuel at idle for one minute. If you get a couple liters your system is most likely in good health. The only thing you don't know is the accuracy of your FPR but they don't fail often.
If your bike won't start the test is to connect the hose and make sure you have at least some flow for two seconds at key on. That says the pump has pressurized the system enough to open the FPR.
I keep a hose with a QD for just that purpose. The kit below has a collection tank and fuel pressure gauge with QDs but the best part is the two foot hose with one QD that couples to the line going from the distributor back to the tank. If I'm pushing fuel out that line, the rest of the system is good.
The return hose is light enough that you can add it to your tool kit for longer trips.
RB
PS: What often goes wrong are fine cracks in the in-tank hoses that can leak for years before they suddenly rupture. The return test may give some warning to avoid this event: Fuel System Failure and Highway Breakdown.
The in-tank pump has a capacity at standard pressure of about 120 liters per hour, which is 2 liters per minute. At idle the bike uses very little fuel. Therefore in a good fuel system there is about 2 liters per minute returning from the fuel distributor to the fuel tank.
To make the test you need two feet of hose with a female QD installed on one end and a collection tank. Open the return line QD (upper QD pair on an 1150 RT), plug in the hose and measure the fuel at idle for one minute. If you get a couple liters your system is most likely in good health. The only thing you don't know is the accuracy of your FPR but they don't fail often.
If your bike won't start the test is to connect the hose and make sure you have at least some flow for two seconds at key on. That says the pump has pressurized the system enough to open the FPR.
I keep a hose with a QD for just that purpose. The kit below has a collection tank and fuel pressure gauge with QDs but the best part is the two foot hose with one QD that couples to the line going from the distributor back to the tank. If I'm pushing fuel out that line, the rest of the system is good.
The return hose is light enough that you can add it to your tool kit for longer trips.
RB
PS: What often goes wrong are fine cracks in the in-tank hoses that can leak for years before they suddenly rupture. The return test may give some warning to avoid this event: Fuel System Failure and Highway Breakdown.
