New carb - idle revving like crazy!

[johnnymac01]

Gday guys.

This is probably something simple - but I've just put my new 17.5 PHVA on, and it starts, but instead of idling it just starts to rev to the sky before I cut the engine! Even with the choke off.

I've checked that the throttle cable is installed OK, and it seems to close as much as it can - and open correctly. I tried messing with the idle screw, but it doesn't seem to affect it at all.

Thoughts?

On another note, I've realised that the stock airbox rubber opening doesn't cover the new carb, as the diameter has increased over the old. What do most people do to keep the stock airbox - which I'd like to do? Modify the whole thing to accept a bigger hose?

Thanks all.

JM

[johnnymac01]

OK. Think I've figured out what's wrong.

Contrary to what I thought the throttle ISN'T closed fully in idle position, as the throttle cable isn't long enough to let it all the way down!



Anyone know how I should get around this? A shorter 90 degree bend would prob do it, can you get them? One I have is quite short already....

Or shall I cut away a section of the brass throttle cable end to effectively lengthen the active cable end?

JM

[90GTVert]

I can fit the stock aribox over my 21mm DellOrtos with the 38mm adapater on the carb. Some airboxes fit over easy, some are a hassle to install, but they all work for me without mods. Not sure what size the mouth of a PHVA is.


DellOrto sells different adapters.
www.dellortodirect.com/Parts/PHBG-Parts/All-PHBG-Parts?zenid=4aqgkoub38nnh7lr75a8pldtn5

[johnnymac01]

Thanks 90GT.

Got it sorted. Pulled the handle throttle end and had to use a hot knife to change the throttle stop postition.

Worked a treat! Idles sweet and ready to tune tomorrow.

Will suss out the air box diameter again, but I think it's gonna be too small. Will sort if I can't get it to fit, I reckon. Seen some threads for air box mods so will see.

Thanks mate.
JM