Update
Well as I started this thread, here’s my update so far.
Thanks for all the replies and info which has been posted and Archie today for helping me with my first carburettor project.
Today with help from Archie we have removed carbs and given them a service, they looked quite good from the outside, but clear by their condition on the inside that it had been sometime since they had been looked at, or even if they had ever been to bits?
The diaphragms were intact but very weak compared to the new ones; some of the old O rings were in a state. There was also quite a lot of crud present, which with the help of an ultrasonic cleaner were brought back to good condition. It also seemed that the butterfly on LH carb was not always making its way back to home position and the RH carbs choke systems held from complete closure by the cable.
Everything was cleaned and where possible renewed, the only exception was the butterfly shafts, has didn’t want to remove unless they felt that they needed to be.
Worked on one carb at a time, as I’m easily confused and put back on the bike before starting on the next.
Set mixture screws 1.5 turns out, ensured there was some slack in the cables and took bike for a run to get hot, then on centre stand fitted vacuum gauge, adjusted throttle stops, mixture screws, followed by throttle cables to get even throttle response.
I enjoyed carrying out my first carb service and having someone to put me right as I went along. Thanks again Archie and also for lunch.
However my thirst for knowledge I have a question, the bike has a pure air system, as describe in the manual I have, this being –
1. Tubes from filter chamber to exhaust port on both sides, this I understand is for emissions?
2. Two rubber tubes from carbs inlet tract(the place we used for the vacuum gauge) to a connector in front of air filter casing; another tube into filter chamber connected to 2 values in air filter casing, again I understand its purpose is to prevent severe popping and banging when you shut the throttle off.
I understand that you can blank this off?
However if someone could advise why you would do that and the benefits I would much appreciate?
I will find out if these works have gone some way to improve MPG in the near future, but for sure a very worthwhile exercise.
Well as I started this thread, here’s my update so far.
Thanks for all the replies and info which has been posted and Archie today for helping me with my first carburettor project.
Today with help from Archie we have removed carbs and given them a service, they looked quite good from the outside, but clear by their condition on the inside that it had been sometime since they had been looked at, or even if they had ever been to bits?
The diaphragms were intact but very weak compared to the new ones; some of the old O rings were in a state. There was also quite a lot of crud present, which with the help of an ultrasonic cleaner were brought back to good condition. It also seemed that the butterfly on LH carb was not always making its way back to home position and the RH carbs choke systems held from complete closure by the cable.
Everything was cleaned and where possible renewed, the only exception was the butterfly shafts, has didn’t want to remove unless they felt that they needed to be.
Worked on one carb at a time, as I’m easily confused and put back on the bike before starting on the next.
Set mixture screws 1.5 turns out, ensured there was some slack in the cables and took bike for a run to get hot, then on centre stand fitted vacuum gauge, adjusted throttle stops, mixture screws, followed by throttle cables to get even throttle response.
I enjoyed carrying out my first carb service and having someone to put me right as I went along. Thanks again Archie and also for lunch.
However my thirst for knowledge I have a question, the bike has a pure air system, as describe in the manual I have, this being –
1. Tubes from filter chamber to exhaust port on both sides, this I understand is for emissions?
2. Two rubber tubes from carbs inlet tract(the place we used for the vacuum gauge) to a connector in front of air filter casing; another tube into filter chamber connected to 2 values in air filter casing, again I understand its purpose is to prevent severe popping and banging when you shut the throttle off.
I understand that you can blank this off?
However if someone could advise why you would do that and the benefits I would much appreciate?
I will find out if these works have gone some way to improve MPG in the near future, but for sure a very worthwhile exercise.
