Bonneville America Forums Forums Technical Forums Performance Mods TBS Needles & Carb Piston Hole

I installed the TBS needles. WOW!! What a difference. In the process, I ran across something I had not seen in 4 years on this site. After installing them, but before I replaced the gas tank, I checked the manual again. It said "Insert the needle into the piston and fit the retainer. Position the retainer so that it does not block the air hole in the pistion." AIR HOLE IN THE PISTON? I took the carb tops off and sure enough one of the retainers was covering the AIR HOLE, which I had not even noticed. The air hole is clocked straight forward. I rotated the retainer and put it all together again. It runs fantastic! What would have happened if I did not "uncover" the air hole-I don't know. But I write this so people can be aware to check the retainer "clocking" position to ensure the air hole is not covered.

Interesting, I will be shiming today. I'll check it out also.

first I've heard of that I always just drop them in. let us know what you see Reido. maybe the newer ones are different

Never got to it yesterday. Going out in a few minutes to jack with it, so sometime today.

That's what I get for never reading instructions. Now I have to look at mine, too.

I think Pat skipped this that step in his shimming the carb page also. I'v never paid any attention to position of the spring retainer. Guess i'll have to check mine now too.

I read that long ago and i recall checking when i was in there and realizing it doesn't matter for some reason. It's been a while since then, so i cannot recall why. But i think the thing doesn't cover the hole no matter how it's oriented or something. Whatever i found when i checked that out after reading that, i determined i didn't have to worry about it. Maybe it was written concerning a different slide that was formerly in these carbs or something.

Ok I just got done shiming and checking this out.
The retainer has 4 legs and the little do-hicky that it sits on inside the slide has 4 notches on it. It will not allow you to put it in blocking the hole.
As long as you make sure you put the 4 legged retainer all the way in and to the bottom it is just fine.
Cheers! Off to the beer I go. Hi ohhh Hi ohhhhhhh YeaAHHH

thanks for the investigative work RD, a beer well deserved
mike

Mine was an 02 model TBA. The retainters on mine could rotate. They must have changed it for the better.

P.S.
I can't believe how much difference that ittie bittie .5mm shim made to the throttle response of my bike. I thought I was Harry Potter with my new broom for a second!
PAT - I just put the new Heineken keg in the fridge! C'mon on down.. Hurry.
(throttle position/Pat... i just had to go to beer)

As you can see, the five legs leave the hole open. At least on the 06TBA.

I have no idea why I said 4 legs earlier. Whack!! There I did it for you.

According to your picture, the carbs on my 05 America are the same design: 5 legs on the spring retainer with grooves that keep things lined up so as not to block the slide vacuum port.

Kewl, that's 2 years down.