Strange sound like exhaust leak coming from intake side

[Advwannabe]

I thought it was an exhaust leak at first, loosened the radiator and oil cooler and tighened all the flange studs. No change to the noise, a pulsing hissing sound, which rises and falls with engine revs.

Getting down close to the bike it sounded like the noise was actualy coming from the intake side of the engine. Steering head bearings need replacement and the throttle bodies need a clean so may as well pul it down.



Once I got the tank off I could see that the little pipe that runs to the TPS from the middle cylinder throttle body had come out. I've since reinstalled it. Could this be the source of the noise? Anyone had this before?

I won't know till I reassemble things and run the motor. I've also checked the plug while I 've got everything apart to make sure they weren't loose, aother of my theories. They weren't.

Second question for Tigger experts: I want to clean and lube the linkages around the throttle bodies. As you can see I do a lot of gravel running. Therefore I don't want to grease them as that will attract more muck, which will turn int grinding paste, etc etc.

If someone has a recommendation I'd be glad to hear it, otherwise someone with a fuel injected dirt bike might know? 

[Chris Canning]

I'd spray e'm with what I use on my chain Wurth dry  lube,I never get any shit stuck to it.

[Advwannabe]

Thanks Chris, any other input on the chuffing sound? Guess I'll find out if I've fixed it when it goes back together....

[Advwannabe]

Yes the hose into the idle control valve( the thingo in the picture) was the culprit.

For anyone else facing this issue and thankfully from the lack of responses it is uncommon, You will hear a chuffing like an exhaust leak, but when you kneel down beside the motor it will be apparent that it is coming from the inlet side.

Steering head bearings replaced, forks rebuilt, now to Tigger ready for it's rego inspection

[metalguru]

Not entirely sure that i will stay fixed for long. Those convoluted pipes will need replacing with some 5mm silicon vacuum pipe and the Idle Air Control Valve cleaning.

As for cleaning the linkages, with a Cold engine use some petrol or if you have a pressure washer then either will do the trick, obviously masking the inlets. Then spray with a dry teflon lube, don't forget the throttle cable while you are in there.