Fuel injection.

Hi have to replace my fuel injector. Q is do I have to depresure the fuel line? If so do I have to disconnect the electric connection under the tank or just pull the fuse? Then hit the starter button to release the pressure?

Pretty sure you need to disconnect the electrical connector, hit the start button a couple of times to release pressure and then Carefully disconnect the fuel connector. The fuel connector is tricky. There is a video about that here I believe.

There is a YouTube video called: Guzzi Quick disconnect fuel fitting
Take a look at that.

Will do thanks . I thought that I could have just pulled the fuse that controls the fuel pump, injectors, and hit the button to release the pressure. Do you know if there any information on replacing the injectors? Ie disconnect the fuel line from the injectors?

Hi Banders.

The injector connection is held in place by a screw (can't remember the size) at the injector. It is sealed through the use of an O-ring and should just pop off, once the screw is removed. If pressure is still in the lines, it will be released as you disassemble it - no real need to got the tank disconnect in this case.

A small amount of fuel will leak out anyway, so have a spill rag in place for the first one - the other side, even less.

When reassembling, use a small amount of rubber grease, on the O-rings - it will assist.

Replacing the injectors is not hard at all.

Thanks replacement injectors in. Bike still running on 1 cylinder? New plugs in got spark. It's doing my head in, spark fuel air, still won't run on 2 cylinders. Getting close to a box of matches. This only started when I parked up for the winter, same as every year.

Seized valve? Loss of compression?

Compression test required.

Compression should should show both sides at 170 psi or higher. If not, more exploring is required

I think I suggested this a couple of days ago. Until you've confirmed that it is compressing the charge everything else is moot at this point. You say it has spark. You say it has fuel. That means that it must be pump related, either the gas isn't getting to the cylinder or it isn't being compressed.

In my experience injector failures are extremely rare so I think they are unlikely as a cause. Likewise plugs. I think I've had one duff plug in the last decade. It was such a rare thing it took me ages to isolate as it didn't even occur to me until I'd exhausted just about any other avenue!

The most likely culprit I still think to be ignition related because a sudden, catastrophic, valve failure is pretty unlikely in the circumstances you've described but running a compression test will rule it out.

Now I believe we have two Pommy posters with similar issues at the moment so I may well be confusing the posters of two separate threads. If so I apologise. I'll ask again has the bike shown any reluctance to rev beyond about 6,000rpm since it was rollerised?

It did feel flat when opening up, was expecting the kick everyone talking about above 5000 rpm but nope more honda like bit disappointed.

I suspect a cam may be out a tooth. Not hard to check.

If this is the case it may well of dropped a valve.

Set it up at TDC compression on the dead cylinder and check the valve clearance.

If there is no clearance on one valve it doesn't portend good.

Do the compression test.