Weber tuning obsession?
Discussion
I can't wait for the weather to clear up and for an hour of free time. I want to get out in the garage to tune up my carbs (again).
I just finished reading a whole slew of different weber related documents. My wife thinks I'm nuts, but I'm on a personal mission to get an optimal tune out of my twin webers.
I think I've got too rich a setting on my idle screws and too low a setting on my speed screw. Lots of advice on the web seems to say to have 2.5 turns on the idle mixture. I'm more like 3 turns. The low speed idle method says that this is too rich. I'm also tempted to check my float level after fitting new needle valves.
She is running pretty good right now, but without a lot of power until full throttle. I have a pretty weak mid range.
Of course, I will carefully record my current setting before I mess things up with my amateur efforts.
Once I have the carbs set, I may once again dial up the timing.
I find it really rewarding to fiddle under the hood and then test out the results. One more reason to love a classic Seven
I just finished reading a whole slew of different weber related documents. My wife thinks I'm nuts, but I'm on a personal mission to get an optimal tune out of my twin webers.
I think I've got too rich a setting on my idle screws and too low a setting on my speed screw. Lots of advice on the web seems to say to have 2.5 turns on the idle mixture. I'm more like 3 turns. The low speed idle method says that this is too rich. I'm also tempted to check my float level after fitting new needle valves.
She is running pretty good right now, but without a lot of power until full throttle. I have a pretty weak mid range.
Of course, I will carefully record my current setting before I mess things up with my amateur efforts.
Once I have the carbs set, I may once again dial up the timing.
I find it really rewarding to fiddle under the hood and then test out the results. One more reason to love a classic Seven
I got pretty handy at tuning - balancing by ear with a short hose pipe for example.
I went to look at a Zetec 7 that was for sale - poor thing was miles out of tune. After 5 mins I had it singing away. The then owner could not believe that it was possible - he would have put it into to his local garage and paid ££'s for the service. It drove ok on the test drive but the car was not for me.
They are like playing an instrument - you have to practise regularly to keep in form:-)
The Synchroniser suckometer takes all the guess work out of them though - precision balancing.
It sounds like you may need to start swapping some jets to get that power back but fastest idle out of the slow running screws + 1/4 turn, proper balance and make sure no air can get past the top hats gaskets will get you a long way...
I went to look at a Zetec 7 that was for sale - poor thing was miles out of tune. After 5 mins I had it singing away. The then owner could not believe that it was possible - he would have put it into to his local garage and paid ££'s for the service. It drove ok on the test drive but the car was not for me.
They are like playing an instrument - you have to practise regularly to keep in form:-)
The Synchroniser suckometer takes all the guess work out of them though - precision balancing.
It sounds like you may need to start swapping some jets to get that power back but fastest idle out of the slow running screws + 1/4 turn, proper balance and make sure no air can get past the top hats gaskets will get you a long way...
It's a while since I fiddled with Webers, so I'm a bit rusty, but I've had a crossflow and a twincam with them in the past. As I remember it, once the throttles are opened the idle mixture screws have very little effect. So I doubt you'll find it will make any difference to the midrange. Once the idle mixtures are set, they shouldn't need adjustment, I used to find that all I needed to do was to occasionally balance the carbs by ear and the reset the idle speed.
Anyway have fun, as you say as long as you make a note of the current settings, you can always go back.
Anyway have fun, as you say as long as you make a note of the current settings, you can always go back.
Thanks Eugene.
Its a 1700cc Crossflow Ford Kent. There are two DCOE 40 webers with 1.75 float needle valves. I have not checked the spec of the jets yet.
The distributor is tied to a Lucas electronic box that appears to control the advance
I think I'm on the road to better performance. Here is what I've done to date:
-Reset the timing to about 14 degrees at idle
-Installed a fuel filter
-replaced most of the easy to get to carb gaskets
-replaced the float needle valves
-Adjusted the balance by ear
-Ordered the proper spark plugs. Hope to install soon.
I'm unscientifically suspicious I may be running rich based on the darkness of the old plug heads. I will test this theory soon by trying out the best lean idle method.
Its a 1700cc Crossflow Ford Kent. There are two DCOE 40 webers with 1.75 float needle valves. I have not checked the spec of the jets yet.
The distributor is tied to a Lucas electronic box that appears to control the advance
I think I'm on the road to better performance. Here is what I've done to date:
-Reset the timing to about 14 degrees at idle
-Installed a fuel filter
-replaced most of the easy to get to carb gaskets
-replaced the float needle valves
-Adjusted the balance by ear
-Ordered the proper spark plugs. Hope to install soon.
I'm unscientifically suspicious I may be running rich based on the darkness of the old plug heads. I will test this theory soon by trying out the best lean idle method.
When I owned an Elan, I stripped and serviced the Weber carbs. I found this haynes manual very helpful:
http://www.amazon.co.uk/Weber-Carburettors-Owners-...
Assuming they have the correct main jets fitted, adjusting the balance and idle adjustment isn't that difficult.
http://www.amazon.co.uk/Weber-Carburettors-Owners-...
Assuming they have the correct main jets fitted, adjusting the balance and idle adjustment isn't that difficult.
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