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View Full Version : 1.2 Carb idle speed adjustment


Welsh Dan
17-12-06, 12:24 PM
Firstly I consulted Haynes, then I used the search to no avail.

Recently when cold my engine has been cutting out. Its not abrupt like the ignition has been cut, it drops to 5-600 rpm for a few seconds then stops, starts straight back up afterwards. Its fine if i keep my foot on the accelerator to keep the idle around 1500rpm and it normally idles around 1100-1200rpm when warm.

This morning I changed the air filter element which was a bit dirty, and I want to up the idle speed a bit but I can't find out how.

Could someone please describe where on these pics the idle adjust screw is please?

http://www.xen0phobiak.f2s.com/novaload/diamond/carb1.jpg
http://www.xen0phobiak.f2s.com/novaload/diamond/carb2.jpg
http://www.xen0phobiak.f2s.com/novaload/diamond/carb3.jpg
Adam
17-12-06, 12:41 PM
1100rpm-1300rpm is quite high for a warm idle, should be 800/900rpm.

I think the idle is controlled using a stop screw, as to where that is on the carb im not sure, must be something around the throttle linkage
Adam
17-12-06, 12:42 PM
On the first pic, if you look the linkage rests against a stop screw, that must be what controls the natural idle, you can see it just above the black end to the metal linkage rod.
Adam
17-12-06, 12:45 PM
http://img.photobucket.com/albums/v86/Nova-crew/carb1.jpg

There might be a metal cap over the other end, if there is smash a screw driver through the cap and lever it out, should be a screw head behind it.

It could be the idle mixture causing it to bog down too... Might be worth getting it to a garage on a tuning machine.
Welsh Dan
17-12-06, 01:07 PM
Thanks :).

I might stick it in early for its MOT next week (due the end of jan), because the outer passenger side CV is knocking and I don't want the hassle of changing that if its going to be written off a month later (:(). If it passes cheaply enough I'll get them to adjust the mixture then.
Adam
17-12-06, 01:24 PM
Take it mot start of Jan, so if it passes you'll get 13month, if it fails you can decide what do with it.

Probably easier just fit another shaft than trying to fit a new cv(proper messy job,Lol)