I have exactly the same problem as the video below:

https://www.youtube.com/watch?v=yMfsDp-yLjw

How is this possible ?

Remove the small stop screw on the left side of the left carburetor. It prevents that the left throttle valve can close completely and is only opened via the mechanism between the carbs, which is adjusted with the sync screw.

If this does not help, remove the carbs and check with a feeler gauge, if the throttle valves are open equally wide. Also check if the intake manifolds are good. See also: http://www.tr1.de/pages/forum.php?iQuery=num=1485863663/10 and the picture at the end of the page.

Do you mean the right carburateur? Because there is a extra idle speed screw. But this idle screw is locked with a nut

Well, i believe left carburetor means the left carburetor. ;-) Left and right are always meant in driving direction.

But you have located the screw that i meant, it is secured with a nut.

I just decided to proper clean and rebuild the carbs again for best result. I cleaned all parts with my ultrasonic cleaner. I also bought 2 revision kits for the carbs:

Fron cylinder:
http://www.ebay.com/itm/251669035275

Rear cylinder:
http://www.ebay.com/itm/251669036743


These revison sets are different, be aware of it !

I adjusted the float hight on both carbs (measured without gasket) to the described dimension (15,8 mm +/- 0,5 mm).



The next thing i want to do is to adjust the butterfly on both carbs, so the engine can start. But i have some questions about that:

-If the bike is running idle, does the butterfly have to be open a little bit on both carbs? If yes How much wil that be?
-Do i adjust this opening with the left idle screw?


The next video shows how de carbs are at the moment. The first butterfly opens en de second one a little bit later. Don't they have to be open at the same time ?

https://www.youtube.com/watch?v=X1tGtJ2Vv9Q

If i turn the synchronize screw all the way in (as far as possible) the butterflys will be opening at the same time, but i dont think that is oke.



So my main question is how do i adjust everything so i can start the engine

The butterflys must be open a little bit and they have to be open equally wide. Use the synch screw to adjust them accordingly, and remoce the left idle screw! Use a feeler gauge to adjust the butterflys so that that they open equally, then mount the carbs and use the right idle screw to adjust the idle speed to about 1100 rpm.

i just removed the left idle screw, turned de synch almost all the way in. Now the opening is on both sides equal, but i have only 3 turns left on the synch screw. So that means i have a little range to adjust the synchronization with running motor.

I hope this will work now and otherwise it has to be the roller inbetween the carbs. This roller has a diameter of 15,8 mm en de gap is 16,2 mm. When you open the right butterfly, the roller clears the clearance ( 16,2-15,8 = 0,4 mm) and after that starts to opening the left butterfly. Maybe if i can make de clearance smaller bij making a new roller the synchronization screw has more turns to adjust it with running motor.

Thanks for help anyway  ;D

De left idle screw needs to be screwd in until it is slightly touching the arm, am i right ?

derbibass wrote:

De left idle screw needs to be screwd in until it is slightly touching the arm, am i right ?

No, it should be thrown away as far as possible. ;-)

in which direction ? Left ore right ?

think about environmetal protection - dispose it properly. Otherwise you might be wondering why your tire is running flat some time.  :) :) :)

However, your assumption is right - the left idle screw should just slightly touch the arm when screwed in. This would be initial condition when I bought the bike in 81. But - Georg is right as well, the screw is not needed at all.

Jürgen