ET: Engine (Twin) Fuel and Carb Settings

Robert Watson

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Try lubing all the cables as if they have been sitting for a while they can get sticky as can the splitter box. Also if they are older cable there were some around that had lovely nylon liners. Trouble is nylon is hygroscopic and swells up with water making them stiff to pull. Also check to see if there are any small catchy edges on the slide and jet block. Taking carbs apart is fun!
 

Bill Thomas

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Just take the spring out and stretch it a bit.
Also see if there is a groove where the slide touches the stop screw, Maybe just file it flat there ?.
 
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Bobv07662

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Reporting in on the spring stretching...idle was better but still slightly hanging up but no where near as much as before. Just the rear carb. I have ordered a replacement AMAL cable return spring and will report back.
Bike is running quite well and continues to impress me. Hard to believe it's 70 years old!
Thanks again for all the support.
 

BigEd

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VOC Forum Moderator
Your persistence has paid off, sometimes it is the small things that make the difference.
If you haven't already done so check that the carburettors are balanced, i.e. starting to lift at the same time from tick over and the same amount with the throttles open. It can make a difference in starting and smoothness. I find using vacuum gauges to check is easiest and more accurate, pulling the same vacuum on the throttle stops and equal value with the throttles open a little. You can also do it manually without the engine running using maybe two drills the same size trapped under the slides and see that they are released together when you ease the throttle open.
 

Bill Thomas

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Morning Bob, You are using the standard two into one small round box on the throttle cable ?.
Some people use two cables, Which I don't think is a good idea, You are forever readjusting those,
Just my thoughts.
The other thing is the run of the cables, Make the bends as smooth as possible, Could be your trouble ?,
They both have a tight turn, where the go into the carb's,
Some people make brass or something bends close to the carb's,
Good idea but I have never bothered.

I know what you mean about 70 year old, I sometimes expect TOO much :) .
 

Bobv07662

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Ed, I've synced the carbs using both methods, manually with the drill rods and then while it is running with a Uni-Syn flow gauge. The balance is spot on and the bike does run quite well.

Bill, the bike does have the standard 2 into 1 splitter on the throttle cable. The cable routing is as smooth as I can make it. I purchased some snap-on plastic guides for the cables where they enter the top of the carbs but those seemed to require excessive force to get them to click on, so I did not install them.
As far as expecting too much, the way the bike runs now I'm happy with it and even rode it on the highway up to 70MPH this morning. It has lots of power, pulls smoothly and rides great. The brakes are much better than some of the other antiques I have. Happy days!
Next project will be to see if i can get a little more modulation into the clutch application but that's will be the subject for another day and another thread.
Edit three.jpg
 

BigEd

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VOC Forum Moderator
Ed, I've synced the carbs using both methods, manually with the drill rods and then while it is running with a Uni-Syn flow gauge. The balance is spot on and the bike does run quite well.

Bill, the bike does have the standard 2 into 1 splitter on the throttle cable. The cable routing is as smooth as I can make it. I purchased some snap-on plastic guides for the cables where they enter the top of the carbs but those seemed to require excessive force to get them to click on, so I did not install them.
As far as expecting too much, the way the bike runs now I'm happy with it and even rode it on the highway up to 70MPH this morning. It has lots of power, pulls smoothly and rides great. The brakes are much better than some of the other antiques I have. Happy days!
Next project will be to see if i can get a little more modulation into the clutch application but that's will be the subject for another day and another thread. View attachment 36118
Looks good and goes good too. Nice bike.
 

Bill Thomas

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VOC Member
There is LOTS more left Bob, But if you want it to last, Don't go there :D .
I once did 124 mph in third on an airfield, Timed !!, On my tuned road Bike !.
6000 rev's is 110 mph in third !.

Super looking Bike Bob, Your mudguards fit better than I have ever been able to fit, Top Job.
 

macvette

Well Known and Active Forum User
Non-VOC Member
Morning Bob, You are using the standard two into one small round box on the throttle cable ?.
Some people use two cables, Which I don't think is a good idea, You are forever readjusting those,
Just my thoughts.
The other thing is the run of the cables, Make the bends as smooth as possible, Could be your trouble ?,
They both have a tight turn, where the go into the carb's,
Some people make brass or something bends close to the carb's,
Good idea but I have never bothered.

I know what you mean about 70 year old, I sometimes expect TOO much :) .
I use these ones my D twin only on the throttles. I have the standard cable splitter
Get them from Venhill, afew quid each code FB9
With a little fettling the tag is fixed by the scew for top of the
20200726_074118.jpg
20200726_074118.jpg
slide
 
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