Throttle being weird...

[DERBIXTreme]

Hi guys,

Basically I was on my way to college today and just before I turned into the junction (bike is restricted to 30 btw if it makes a difference), going from full throttle to no throttle. Upon accelerating out of the turning, I noticed it was revving more than expected and the throttle didn't have any resistance to turn like it usually does.

Ive just ridden it home and it sounds like its revving more than normal. I pulled over and had a tinker with the throttle but this didn't make a difference. Ive also noticed if i hold the throttle barely above closed (literally turning no more than 5 degrees) the revs increase, getting to about 8000 RPM in 5 seconds from holding the throttle open very very slightly not moving!

Anyone know whats up? The throttle hasn't been like this for the last year and only changed today

bike is a Derbi Senda DRD R 50

[at106]

There could be two causes, the first is that the throttle cable is too tight (not routed correctly) i would start the bike in neutral and then turn the handlebars from side to side, if the revs increase then the cable is too tight. Also make sure there is a few mm of free play in the throttle body at all steering positions.

You could also have an air leak, start the bike in neutral and spray wd40 around the carb, if the revs change then you have an air leak.

[Rogerborg]

[DERBIXTreme]

[Vincent]

I'd say it was the "throttle cable not routed" idea. The cable gets caught so when you turn the throttle tube, there's no resistance. Deffo get it sorted, 'could have dire consequences At standstill, and with the engine runing, try moving the bars from one lock to the other, see if the revs go up.
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