Rough running 1150gs

[Ian J Hartley]

It's worth checking the injectors to make sure they are spraying a nice spray pattern and not partially blocked.

Do you think you have good fuel pump pressure?

I'm more inclined to think you have either an air leak (throttle bodies) or maybe fuel pressure/supply problem.

Let's face it you have changed everything else and the bike runs, but no fault codes, so what ever the problem is, it's outside the motronic control.

You could try disconnecting the return fuel line to the tank, and see if that improves, it should boost the pressure in the manifold, as it takes the fuel pressure regulator out of circuit. The fuel rail will be at pump pressure. might allow more fuel to be available, for the injectors.

Just a couple of suggestions.

Good luck
Ian

 

[itbeme]

I have pulled the injectors and tested the pattern and it has a nice broad pattern, as shown in examples on the net. I have run an Ohm meter across the injector terminals and get 16.6 Ohms. That seems to be with in range. I tried disconnecting the return gas line and it seemed better at first, but as I rode it it would sputter at stops and pulling away, it went back to cutting out. WOT was better, but if I can not pull away from a stop, what is the point. I will try and test fuel pressure to see if that may be the issue. I also tested the "u" shaped hose from fuel pump to filter, no cracks or leaks. I am almost getting ready to go back to my airheads, if this bike wasn't so nice to ride. AAAAAAAAAARRRRRRRRGGGGGGGGG!!!!!!!!!!!

 

[Ian J Hartley]

I take it you have used your GS911 to monitor the real time values.

Things like air temp and oil temp values are stable and indicating what you would expect.

Things I would check.
Air leaking between the throttle body and cylinder head.
Compression check.
Both your throttle bodies are moving in synch, and return together. Checking you don't have a throttle cable binding problem.

I wouldn't give up, there can't be much left you haven't changed or checked.

Ian

 

[Galactic Greyhound]

It sounds like fuelling and there is insufficient fuel being delivered at wider throttle openings possibly due to a ruptured hose or leaking connection inside the tank.

However, first see if the bike runs better with the fuel cap cracked open in case there is a partial venting blockage causing a vacuum inside the tank and so restricting the fuel flow.

If it is not a venting problem, then it could be incorrect air/fuel mix.
The bike will run OK while the air/fuel ratio is at 15:1 but, if the fuel is limited, then at Wide Open Throttle (WOT) the ratio will be incorrect (too weak) and there will be too much air passed to allow proper combustion if any.

Disconnect the fuel Return hose and insert it into a clean, clear, 2 litre bottle (Coke bottle).

With the engine running, there should be a Flow Rate of 2 litres/minute.

Check the amount of fuel delivered after exactly 1 minute.
If there is not 2 litres in the bottle the fuel hosing, connectors and Fuel Filter inside the tank should be checked for leakage/blockage.