Bonneville America Forums Forums Technical Forums Performance Mods performance mods

I'm new to this forum ,have browsed some. I bought a black 06' speedmaster last year. love it! Recently bought thunder bike pipes from new zealand this year. 3 turns out,de-snorkeled. popping. Dinqua says get rid of AI in one of his many columns to reduce popping? My Goals - 1. AI out. 2.130/42 3.K&N single 4.TBS needles-Where can I find? 5.18T sprocket. with these mods will I have to modify my airbox as in cutting holes. I'm aware of the freak kit. I have researched the drilled air box also. Will these mods be able to perform without 50% more air?

they will help, the drop in K&N wont do much other than allow you to have one filter your can keep and reuse. i would suggest the freak as it not only helps in performance, but it also makes the bike much easier to work on. sems your on the right track tho

Frank

Get the needles from a dealer, unless anyone here has some laying around.

thanks fellas! thinkin about adding the freak to my shopping list.I kn ow itt expensive but maybe I'll tell the wife that I need to make room for a toolkit. as for the needles BIKE BANDIT item#4 part # N3RF Triumph part# T12410240 . just got that info a little earlier tonight. May the wind always be at your backs!

The AI introduces air into the circuit post carburation- hence the decel popping. Get rid of it!

Greybeard, I like your style.

Frank, with your mods in place do you notice a huge difference running 160's 1.60mm as opposed to smaller mains and how is your fuel consumption running that set-up ?

I thought the 06 came with different needles? Basically the TBS needles so that mod was done at the factory?
Anyone? I might be confused here but I could have sworn I read that at some point.

The way I understand the OEM # BONNYUSA states TBS needles Aftermarket # is N3RF Thruxton # NBZT Triumph # T12410240 Which is okay if you have the twin keihin T1242700 of Which I don't on my 06' black & chrome speedy I have the twin keihin T1245050. Run of the mill OEM # ( No special # )Perhaps the needles were down graded in the afore mentioned ? At least that's the way I read per diagram and part's listing at BikeBandit. Are there two sets of twins one being set apart from the other in this case? See Tech vault, pick intake/carbs go to carb info and mods--- see Triumphants web page;"TRIUMPH Thunderbird sport" needle for T1240680 Twin Carbs.(TBS)

My 06 speedmaster came with NBZY. Currently running NBZT w/ 2 shims. Will be running a comparison soon and selling one of the sets.

I don't even need to fabricate like I do at work welding that is. It's a done deal I think . Question? The purpose of the shims on the needles. Is it because of thier extra length in comparison to the others ? Extra fuel flow?- like a dead stop or something or the other way around.I'm a stainless welder and a backyard mechanic I can always usually do about any job if I gather enough info. (and a manual of course) Could use some input on the matter. As always thanks again and we'll keep a light on fer ya'.

The shims bring the needels out sooner. Your carbs operate in stages. The polit and mixture screw meter fuel off idle to about 1/3 throttle where the needles pick up until about 2/3 throttle. The main takes over from there. If your flat in the midrange, like many of us are on these bikes, a shim or two usually perks it up. In the above, how much each and where is not exactly right- there is some overalp and what not, but you get the theory behind it. Check out Dinqua's page- it has step by step on rejetting, shimming and more... http://www.dinqua.com/Triumph/carbs0.html . Another source is a carb theory page here http://www.motorcyclecarbs.com/carbs101.pdf .

With these mods in place ,even if I decide to go from a larger sprocket say a 17/42 or 18/42 I'll get more torque then at the line but decrease as I get close to a ton.(I'd always opt for the performance off the line because I don't run a ton every other day. With you guys mods in place has anyone of you watched the odometer vs. MPG ? Thanks again , and we'll keep a light on fer'ya' P.S Thanks for the motorcycle carb 101 theory pages I'm going to print that for future reference. P.S. Is that why the america has a larger maximum power with the 17T sprocket but a lower Torque value than the speedmaster? I've seen that all the gear ratios are the same including the primary drive,the only difference is the final drive 17/42 which gives it a 6 HP jump in max. power at 900 more RPM's than the speedmaster.Speedmasters Max. torque 68NM or 50.156 ft-lb at3500 RPM while the america Max torque is 60NM or 44.256 ft-lb. (keep in mind these are wihout mods) So the final drive ratio on the speedmaster is 2.63:1 to americas 2.47:1 Which means Speedy's 16T sprocket makes 2.63 revs=1 whole turn on 42T(rear) sprocket Whereas the America 17T sprocket makes 2.47 revs= 1 whole turn on 42T(rear) sprocket. Just tring to see where my gains are on the speedy.