|
|
|
|
| Author |
|
|
Registered
Join Date: Apr 2004
Location: Galway ireland
Posts: 2
|
weber jetting question
I recently bought a 69 912 stock 1600cc with twin webers 40 idfs . I must admit that I have very little knowledge of carbs, but my friend Brian has been helping me out. We balanced the carbs and set the float levels, and checked the timing etc, but still very hard to tune, and the mixture screws are screwed all the way in before you start to get a mixture.
The jets are mains 115, air correction 200, idle 45 and F11 emulsion tubes. I think venturies are 28mm. We changed idle jets to 52 without any noticable difference. Seems to be running very rich and heavy on fuel. Can someone give me a baseline jetting for 40 idfs and maybe advise on what may be the problem. Thanks for you help... j.d. |
||
05-14-2004, 01:57 AM
|
|
|
Registered
Join Date: Feb 2002
Location: Savannah, GA
Posts: 831
|
J D, do a search on this 912 forum, us this in the top left side for the search info - 'weber IDF conversion how to' in the top right use the name 'Sweetheart912' it was a great help to me this weekend as I did the same thing. It will be in three parts, he did a very good description for the conversion and jetting info. Good luck. Jerome
|
||
|
05-17-2004, 03:37 AM
|
|
|
Registered
Join Date: Feb 2002
Posts: 38
|
There are so many variables that you either don't know or left out of your description it is difficult to give you any specific advice.
I am running a big bore with a 280 cam. I have a set of Webers on it with : 32mm vents 125 mains 55 idles 200 airs F11 emulsions 50 acc pumps (.55ccs for 2 strokes) I am going to 40 acc pumps because the 50 is a bit big. The first thing I would tell you is that your venturis are too small and you are not passing enough air, get 32 vents from CB Performance or the like. Next, set your valves cold to the manual settings and ensure that yuor timing is spot on and no more than 33 BTDC at 3500+ RPM. Good luck, erik. |
||
|
05-18-2004, 12:23 PM
|
|
