T509 Running Rough

Hi
My Speed triple is running dog rough, spits back through airbox, and hangs on to the revs. My local shop replaced all tthe airbox hoses, it ran great for 50 mile now the problem is back.

Any ideas please as to the cause?

Cheers
Budgie

 

Hi and welcome. Can't help you, but someone knowledgeable wil undoubtedly be along shortly.

 

budgie955.
Welcome to the family. We need some more info to be of any help. Tell us about the beastie. service, mileage, has it been laid up any length of time. Any recent mods or in fact any mods. And I am not referring to scooters before anyone gets carried away. Picture of the steed would be nice.
Regards
Joe

 

Not been stood, no service history, 25000 miles, previous owner not had any problems. Local shop replaced the air box rubbers as they were perished. Thought that cured it as it ran fine for a while, took it for MOT today, ran fine going, dog rough coming back.

 

WHICH Airbox rubbers?
The common failure is oft he hoses which are between the IACV (Idle Air Control Valve) and the Throttle Bodies - those do not actually connect to the airbox in any way, but not sure if that is what you meant. "
You can replace those with 6mm Silicone hose - the OEM ones have a check valve in the middle, it is not necessary to re-install these.
And then check the throttle balance

 

I am under the impression these were done at the shop, will find out. If these have been replaced , whats next ?

 

Use of the term "airbox rubbers" is what confused here.

Rough is one thing - if the idle speed is high then it's definitely an air leak.

 

You rev it and it the revs take time to drop, but its intermittant.

 

Hello and welcome to the forum Budgie.

 

Budgie955.
Well it seems to be the air box in some way. what you need to do now is check it completely for leaks or trapped pipes. Also check the breather tube to the petrol tank and fuel flow. Check your cables and mechanism is all free and working. Balance the carbs. Check your air filter is clean and free flowing.
Regards
Joe.

 

This sounds like you’ve got a sticking throttle cable, or it’s routed incorrectly.
Could also be that there’s been something trapped against the cable or it’s mechanism when putting the airbox or tank back on; it’s a bit of a squeeze in there.
If you’ve no service history, it’ll be worth doing a comprehensive service including a throttle body balance.

 

cable is fine and not sticking, going to have to look myself at this. Any tips on removing the airbox ?

 

Watch from approx 5 min 50 seconds, ignore the fuel filter bit. Hope this helps

 

Very useful , thanks, my local friendly mechanic says the stepper motor is the likely culprit, likely sticking or seized.