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TT the carb not the Race

vibrac

Well Known and Active Forum Website User
VOC Member
I have had lots of TT carbs but I have just for the first time run some stuff that passes for petrol nowadays into the TT on my Grey Flash (First time? Yes I know but its along story) and its weeping ( drip drip drip from the bottom nut on the body (the one with the eye for a locking wire) tracing it back it comes from the hole in the underside of the body next to the flange, I have a vague memory that the last time it happened on some other 60's racer many years ago I lowered the matchbox float (perhaps invoking the level mark on that brass bung) and all was well.
Of course (unusually for me;)) I am a slave this time to the keep it original brigade, so I have a fixed float attached to the body of the TT ,whats the procedure for lowering the float?-It cant be a stack of fiber washers on top of the float union can it:confused:?
I have a slightly down draft carb (say 5 degrees) and a horizontal float chamber so thats tilted as well but I seem to recall that the angled floats are at 15 deg angles so that would tilt it back 10 degrees so I think thats not in the equation, it could also be I need to brasso the float taper but the question remains ,how do you adjust the float level on a fixed TT?
 

greg brillus

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VOC Member
Tim from what I've seen, you can get the fixed float type 302 large bowl in different angles, I will be wrong here but I think in 15, 7.5 and 5 degree ones. Sometimes the manifold combination makes perfect vertical alignment difficult, but you need to get it as close as you can. I have several types and angles....I found on the twin racer that I could not get the front cylinder level correct....too high...so I have gone to the same float but in a remote mount type of fixing, hopefully this should work out ok.....I have made it so I can adjust it up and down, and I have a spare bottom jet cap with a fitting and some clear tube, so I can check the level accurately......Greg.
 

vibrac

Well Known and Active Forum Website User
VOC Member
Yes I have normally used a remote float but they were not standard fitting in 1950 I have had a look at the 7degree chamber but £162 is a lot for 7 degrees I think I will simply move the flange with a 5 degree tapered bakalite insulator so its horizontal-my guess is it will still drip. It does seem there is little room for adjustment-perhaps thats why the TTs back then were the now unobtainable clip fitting then I could just twist the carb a fraction and move the float down-perhaps next winter I will have time to turn a flanged body into a clip fitting
 

davidd

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VOC Member
Yes I have normally used a remote float but they were not standard fitting in 1950 I have had a look at the 7degree chamber but £162 is a lot for 7 degrees I think I will simply move the flange with a 5 degree tapered bakalite insulator so its horizontal-my guess is it will still drip. It does seem there is little room for adjustment-perhaps thats why the TTs back then were the now unobtainable clip fitting then I could just twist the carb a fraction and move the float down-perhaps next winter I will have time to turn a flanged body into a clip fitting

The remote float bowl was a standard fitting in 1950 to Grey Flashes that were raced. All of the TT entries had them and my bike, when it had the big port head also had a remote. Here is a photo of Cliff Venier on my bike at Daytona in 1953 or 1954. You can see the float bowl is attached to the F106 with an aluminum strap:
cycledaytonavincent4.jpg


David
 

vibrac

Well Known and Active Forum Website User
VOC Member
I dont mind owning up-I think most of the problem is my paddock stand I have a high one so I can get a good push on my foxley starter and of course that increases the down draft, Here is Roger Moss on the subject in Scott technicalities. the penny dropped three lines from the end:oops:

I use TTs on both of my Scotts.
The correct float height is found when petrol starts to weep(difficult to see be
patient) out of the "hole" underneath the pilot screw when the tickler is
pushed down for an instant, ie a jab , not a push and hold down. The petrol
should then continue to weep out of the hole, slowly forming a drip.This will
only stop on switching the petrol off. If you have raised the float too high you
must drain some petrol off before starting again. Under static level conditions
there should be no petrol coming out of this hole.
I use a torch to help my aged eyes( you may be more fortunate) , then you can
see the film of petrol leaving the hole before a drip forms.
All tests should be done with the bike level .
Take your time, and you should be rewarded with easy starting and good low and
high speed performance. I think TTs are magic!
 

greg brillus

Well Known and Active Forum Website User
VOC Member
What a great description. I like his final comment......unlike most of my racing club friends who can't for the life of them understand why I want to run such outdated carburetors. I think if they are in good condition with correct jets, and especially on Methanol...I can't think of a better carb.
 

greg brillus

Well Known and Active Forum Website User
VOC Member
The other thing I tried to lower the level was to shim the float down by placing small washers between the needle and the float. Of course it all depends on whether you have a top or bottom feed float bowl to start with, but you can shim both either way. There are limitations from the point that you still need to use the tickler, so shimming too much will effect this. I checked some of the floats I have, and found them at 3, 5, 7 and 15 degrees. It shouldn't be too hard to find a good second hand one in your neck of the woods, I would have thought.....have a look on flea bay....should find one cheap as chips......Not...o_O
 

nkt267

Well Known and Active Forum Website User
VOC Member
Have you tried rotating the carb so that the float chamber is lower. I did this on my Comet to overcome the richness..ie on standard carb rotate anticlock looking from rear of bike to lower the fuel level and vice versa to richen..John
 

vibrac

Well Known and Active Forum Website User
VOC Member
Have you tried rotating the carb so that the float chamber is lower. I did this on my Comet to overcome the richness..ie on standard carb rotate anticlock looking from rear of bike to lower the fuel level and vice versa to richen..John
See my remark above re -clip fitting -you cant rotate a flange
 
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