Triumphrat

DaleE

Over the weekend I finally got around to swapping out the jets and needles on my 2K TBird--which worked out nicely, since the temperature went into the sixties on Sunday, and I was able to give it a good test ride.

Contrary to expectation, it appears that I haven't screwed up my bike at all. But I thought I would let you all know about one small but repairable blunder that I seem to have made.

When people talked about "opening up the airbox" when doing carburetor mods, I got the impression that the goal was completely unrestricted airflow. And so I put my brand new Sears hole saw to work! I cut out five 1.5" diameter holes--this in addition to the existing port, which I left connected to the auxiliary airbox.

I got it all put back together with no extra bolts, hoses, or oddly-shaped doohickeys (hallelujah!) and--best of all--it actually still ran!

But it was certainly no improvement on what I'd had before. It was much worse. Specifically, beyond 4 or 5000 rpm, the engine stumbled very badly.

Well, I thought, what's the easiest thing to change, before I have to take off those carbs again? I can at least try to block off some of those many holes I cut.

So I blocked off two of my five new holes. And you know what? All of a sudden, the bike goes like crazy. The engine just screams during acceleration. No stumble at all. And the time it takes to get from 2000 rpm to redline seems to have been cut in half (okay, total exaggeration, but you get the picture).

So I'm feeling pretty smug and satisfied, but of course I'm not done yet. I've got to try to figure out the optimal conditions for the air inlets. (And then I'll get busy with the epoxy. I saved all the little cutouts.)

My mods were pretty typical: #40 pilots, 115 mains, Thruxton needles, K&N filter, and TOR exhaust. (BTW, thanks again, Wombat!)

Next time there's another warm day, I'm planning to try the various different arrangements of covered/uncovered air inlet holes and drive my neighbors crazy as I accelerate up and down our street. Is there a more accurate way w/o paying for multiple dyno runs?

Thanks again to everyone who offered advice so generously on this forum. It's a real pleasure and thrill for me to have successfully pulled off this modification.

Greaser

I love the Pink Floyd reference!

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" If you haven't been paying attention to what's going on in the world around you perhaps you should start. It certainly beats relying on erroneous rhetoric to form one's opinions." Steven Lloyd

dynamike35

I ues standard holesaw 1", then you buy 1'' black plastic hole plugs and you can play around to get best results, if too many hole plug a few.

patrol21

I just read this and am happy to hear this. Jimmy900 gave me the same advise as I had done the following mods and had the same issue.....death at 4-5K. Your mods are almost identical to mine

MIKUNI's
Mains-Dynojet size (both) tried 120's but immdeiatly fouled the plugs
Exhaust-TOR's but changed out for Emgo shorites (my wife worries I'll get hit as I'm not oud enough-surprise)
K/N replacement for stock filter
Float height-14.5mm
Needles-Dynojet-playing with this right now (on 5th clip, going back to 2nd clip per Dynojet Tech once I plug up the holes)
Pilots-40 (stock)
Mixture-2 1/2 turns

The weather has decided to get cold and stay that way so I havn't had the chance to tinker. Taping up the holes. Glad to hear that you ran into the same issue and had good luck with closing these up.

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The worst day riding beats the best day at work....no exceptions.