My Baby is back ............ but with a niggling problem!

Hi Guys!

So, after 6 weeks without my SW and desperately attempting to service all my private guitar students round Vienna using public transport, the day finally arrived last week when i received the call to say she was ready to collect after her complete engine rebuild! I handed over €1,700 and climbed aboard ....................

It was great to be riding again and the bike felt wonderful! However, I very quickly noticed that the idling revs were not settling down to what they should be (1,300rpm?). In fact every time I stopped at the traffic lights or a junction the rev counter was sat at 2,000rpm and quivering and the engine sound wasn't stable ie rrrRRRRrrrRRRrrrRRR. This was still happening well after the engine had warmed up (3 bars on the temperature gauge). Eventually, after about 40 minutes of riding round town the revs did settle down a bit to around 1,600 without the quivering. As a result I seem to be using about 50% more fuel!

I eventually, popped back to the dealers and described the symptoms, and they simply adjusted the idling speed screw down a little, but as "sods law" would have it the revs were actually down to about normal when I started up the bike to show them anyway, as by this time I had been riding for about an hour to get to the dealers from the other side of the city.

Well that was 2 days ago and nothing has changed! The bike seems to be running fine apart from this gas guzzling problem.

Could it be the choke or thermostat? Does the SW have these devices?

Help!

Thank you for listening .................

SteVe

Glad you have your Silverwing back on the road

As for it running rough, maybe it needs the throttles balanced? Theres a guide here about it but can find it right now...

Is your 400 Swing fuel injected? Did they install new manifold gasket if not you could be sucking air from the manifold connection,or dirt in the throttle body .Try some fuel injection cleaner . A loose vapour connection tube. Shop mechanic often work on a time schedule and some times forget or don't connect things properly .

Hi Tinman,

Thanks for your reply.

My bike is fuel injected and I was told that all gaskets were replaced.

Is the vapour connection tube the clear tube that can be seen on the outside of the engine?

SteVe

No there is the one that recycle un burnt gas back to the manifold .there might be more tubes from the canister. It could be a connector .Trouble shooting,of rough idling is
intake air leak
fuel contaminated
pinched or clog fuel hose
idle speed misadjusted
starter valve synchronization misadjusted

check all hose connections and sensor connection

If you don't find the problem,go back to your dealer and give them this trouble shooting list to check

Also check the spark plug for proper gap,and colour It should be a light tan colour ,dark brown or black is fowled . If it still continue remove the air filter,run your scooter without the filter on a shot run .

Well, you can be assured that the problem isn't mechanical. And given that the ignition is fixed by the crank position sensor & the ECU, that leaves the injection system as the culprit.

As others have mentioned, check the throttle balance and vacuum tubes for leaks. HTH

Tim

Thank you so much for your excellent suggestions!

To my delight today the problem seems to have sorted itself out! These are my favourite kinds of problem )

SteVe

No more Gremlins. Problem solved.

Hello Steve,

Glad to hear everything okay apart from the lightness in your pocket.

Cheers,