Bonneville America Forums Forums Technical Forums Performance Mods question about mods.

I put Triumph long off roads on last fall. The other day I went to 132 mains, went from 3 to 3 1/2 turns on the needles. I pulled out the snorkel and opened up the bottom of the airbox and filter. The bike seems to run better at higher RPM but I notice no improvment at all at lower RPM. What Next?

WOT first, then middle throttle, then idle. Sounds like you got the WOT with the mains, now try a differnt needle (TBS) or put 2 shims under each stock needle and try to get the mid throttle dialed in. After you get that done, get the idle good with the pilot adjust screws or the pilot jets themselves. Most people never need to swap the pilot jets though so don't be in a hurry to do that just yet. Screw the adjuster out about 3-4 turns may help once you get down there, but do the mid range first by playing with the needles/shims.

where is the pilot adjust screws?? I am running modified stock BA pipe. First baffle out 2nd baffle has three 1/2 holes, snokle removed, a/i removed, air screws at 2 turns, 2 shims, 130 mains, sounds good runs good (could always run better) just like to know where everything is.

air screws = pilot adjust screws

I'll try the cheapest thing first. I already have the shims. What about Thruxton neeedles? I've heard they are hotter. Thanks

Larry, even the TBS Needles with no Shims were an improvement over the stock needles (I have Bubs, no snorks and 130/42 jets, and 3.2 turns)

The Thruxton neeedles are 'too hot' for anything but the big bore kit.

Either do stocks with shims or use the TBS....

You may need to go a size or two bigger on the pilot jet. To make a quick test, ease the choke out just a little and see if performance is better in the idle to 3000 rpm range.

Do we have a detailed explaination of how to modify the keihins? Maybe with a few good pictures? These are a lot different than the rochesters on my old chevy and I always had the shop do the carb work on my other bikes. I don't mind doing the work, it's all that time feeling like an idiot I hate :-)

Shameless Self Plug - Pat's Carb Site

I like it. Lots of pictures and small words. Perfect Thanks for your work putting it together.

There should be a link to that somewhere on here....like right under the ATTENTION message......

Maybe a portion of the website could be just links to tech advice. It could be labeled "Hey dummy, look here first!" I especially like the price

Try The Jenks Project for carb set-up data. Very useful & informative.
Two things which puzzle me:
Why go so high on the mains?
Why are Thruxton needles too "hot"?

Thruxton needles have a fairly radical taper and are way too much for an almost stock setup. I am running K&Ns and went with TBS needles to cure a flat spot and they are perfect. Even for me, the Thruxtons would be too much. Dinqua has the big bore kit and he IS running Thruxton needles and for that they are perfect.

High on the main? I thought there was no uch thing as too much (speed)?!

I run 160s and when I crack that throttle, the response is outstanding. I've tried smaller with poorer results. Also, the plugs are a perfect tan....

& the exhaust gas analyser says what? Or does it just feel good to run a set of jets the size of Texas? How close are you getting to a chemically correct burn? @ WOT the Thruxton needles in std 110 jets provide the same flow as std needle in 138's. You have a bloke called Mike Selman @ BellaCorse who could put you straight about this. Perhaps I'm being a tad prissy here but, I really was hoping for a response based upon sound technical knowledge, backed up by data; as opposed to the principle of throwing a bucket of petrol onto a fire. I'm afraid this kind of response merely demonstrates just how much you people deserve George Bush & Michael Jackson. Could whoever runs this site please remove me from the "list".
Bloody Colonials!

Yeah Phil, you Bloody Colonial!!! After all, what do we Yanks know about racing!!! Now go and apologize to His Highness before he trounces us with his Sceptre!!

Lew,

Goodbye and good riddance.

Usually I don't sink to your level but you caught me at a bad time so here we go:

You are not priggish, you are an excretion who thinks his opinion should be law. Your way or the highway, right? What a fool. I don't know what your problem is, but I'll bet it's hard to pronounce.

No one here has to defend how their bikes are set up to a braindead jackoff such as yourself. If you want to run this or that setup, do it. Mine is fine with me and if you don't like that, take both Thruxton needles and stick them where the sun don't shine, you cretinous abscess.

You are the epitome of those that we threw OUT of this country many a year ago and now I see EXACTLY why. I imagine the other British members (all excellent people) of this board are hanging their collective heads in shame from having to call you their countryman. Now don't go away angry, just go away, you addlebrained jerkriot.

"you people deserve George Bush"

Now you're just being an ugly Imperialist Dog Lew!! No need for slanderous tones here! Come out of the closet Lew, admit you voted Labour too!!! Blair lover!!!!

Quote:

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I really was hoping for a response based upon sound technical knowledge, backed up by data;

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I thought tuning was an art not a science? And what's good for one is not necesarily good for another? At least that's what you said in the belt drive thread.

I've been avoiding/ignoring a lot of your posts before, but come on dude, lighten up..