PR: Proprietary Items TT carb
- Thread starter vibrac
- Start date
Thanks for the info, I need to experiment a little. Probably will source some spare slides to play with. Friend of mine believes he may have a couple of slides so may have a go at it soon. Will keep you posted.
Ron Kemp had a 1/4"X1/4" hole at bottom of slide he slowly filed it untill he got a clean tickover
when set up on the MCC high speed trial start he could kick start in one movement and as his foot came up it would engage bottom gear faster than any electric start He had to prove it in the paddock after the marshals thought he jumped the flag.
when set up on the MCC high speed trial start he could kick start in one movement and as his foot came up it would engage bottom gear faster than any electric start He had to prove it in the paddock after the marshals thought he jumped the flag.
I have made a very simple mod to the GP carb on my Goldstar. It could also easily be done to a TT. I added a throttle stop screw. All I did was drill and tap a hole in the top of the slide #12-24, any other smaller size would do. When I tapped it I used a taper tap but I didn't run the tap right through. I left the thread partial so that when I installed a set screw it was really tight, no lock nut required and no chance of it falling out either. I chose a part of the slide where the brass was thickest. To adjust it you do have to take the top off the carb, and on the Goldie you actually have to remove either the tank or the carb to do that. Once done though you never have to adjust it again. On the Goldie I can adjust the idle speed finely with the advance lever anyway. This has the advantage over drilling or filing the slide that you can adjust it faster or slower reversibly. It is a very quick thing to do. If later you decide you don't want it you can just take the screw out. There are ways of putting an adjuster on top of the carb but they are not as simple as this and really the external adjustment is not that big an advantage. It makes it a lot easier to start the engine.
Very interesting posts, looks like I've started something here. I appreciate the simplicity of the idea of including a stop screw in the carb body but I don't really want to drill and tap these clip mount 32mm TT carbs as I believe they are quite rare? I think a mod to the slide is the way forward for me.
I don't think you understand my modification for idling. There is no change to the carb body. I agree you don't want to do that. The stop screw goes into the top of the slide. It is less of a modification that filing a groove or drilling a hole in the face of the slide because you can just take the screw out and then it is just the same in operation as if you had never done anything. Also when you cut a groove or drill a hole in the slide once the groove or hole is to big it is really hard to go back and get the idle slower. With the screw in the top of the slide you can adjust slower or faster. I had a picture of what I had done once but I am not sure where to find that now.
The other modification I did that was very useful was I installed a viton tipped float needle from an Amal concentric into the end of the needle on the GP float. I have found the Viton tipped needles from the concentric last almost forever.
One of these?
https://www.classicbritishspares.co...bloc-viton-float-needle-1-622-197-triumph-bsa
What mods did you do?
https://www.classicbritishspares.co...bloc-viton-float-needle-1-622-197-triumph-bsa
What mods did you do?
Understood, sorry for some reason I had it in my mind we were talking about a stop screw in the carb body. a vertical screw in the top of the slide is a good idea as per Robert's and Oexing's posts. I like the idea of using the taper tap also. Thanks for the info, I will get the bike on the road and experiment. I have other minor issues to overcome before I get to that point such as how to sort out the LH kickstart operation with the brake pedal and footrest, a plan for that is underway.
