Fuel Injection Blockage?

[Jez]

Hi All,

I have an FI 750 SRAD which is quite fluffy at the bottom end of the revs which means the clutch needs to be slipped to pull away. After that it revs fine.

As this is my first FI bike can anyone advise where I might start to look for a blockage? Are there pilot and main jets to clean like a carb?

 

[Underdog]

If an injector is blocked you'd get no fuel through. Imagine a carb runs like a flowing tap, now stick your thumb over the end of the tap to cause a spray, that's the difference between carbs and injection. The fuel flow is different. Injectors are either clear or blocked, not like jets where you can get a reduced flow. If an injector is fubar'd that cylinder won't fire at all. Things you could look at, and I'm not saying it is these, compression, spark plug, h/t leads, fuel pressure regulator, fuel lines, fuel rail. Hopefully it'll nice and easy like new plugs or a cracked plug cap

 

[Jez]

Nice one, Underdog. Thanks for the detailed description.
I am planning to change the plugs soon so will look at leads etc when I do. I don't feel it is fuel line or rail as the bike pulls fine above idle. I have just found out that the previous owner has had the bike for ten years and has not raised the tank except to change the air filter. Fingers crossed.
I will try to remember to let you know how it goes as I do appreciate the advice.

 

[Underdog]

Ten years?!?! Damn it needs new plugs without question

 

[Jez]

Well well well. Turns out the plugs are the culprits (no 2 plug anyway) after all. No 2 plug was so rusty that I was pooing myself as I gently struggled to remove it. I thought it was going to break any second. Valve clearances are ok and oil and filter changed so all is ready for a bit of caning in the spring .
Thanks for the tips.

 

[Underdog]

Yay!! Glad you got it sorted & it was reasonably, if nervy, fix