Triumphrat

cxc190 · 04-22-2007

Hey Folks,

Who out there has installed the BC performance kit?

I finally installed the filter pods and rejetted the carbs. I guess the bike is running to rich now. Has anyone out there had this problem. What size jets are supposed to come with the kit?

In fourth or fifth gear above 4000 rpm the power drops and the bike boggs baddly. It won't run beyond 75 or 80 miles an hour now.

I'll give the guys a call at British Customs tomorrow just wanted to know if any had this issue.

sweatmachine · 04-22-2007

sounds like a lean main perhaps? what size main jet have you installed?

I'm running 42 pilots, one shim, and 155 mains, although some have run 140 mains and it runs well.

rbrian_taylor · 04-22-2007

I put mine on recently, 140 main, 42 pilot. Don't have the same issues you have. Is one of those rubber caps from the manifolds missing?

cxc190 · 04-23-2007

Tech-Guy at BC says to turn the idle mixture screws out 2.5 turns.

I'll try that as soon as I get the special tool... half moon tool

sweatmachine · 04-23-2007

Quote:

On 2007-04-23 13:12, cxc190 wrote:
Tech-Guy at BC says to turn the idle mixture screws out 2.5 turns.

I'll try that as soon as I get the special tool... half moon tool

Do you have stock pilots or larger pilots?

I have the 42s, and I'm 1 turn out.

rbrian_taylor · 04-23-2007

I didn't touch the idle adj screw. I saw somewhere (Jenks maybe) that stock was 2.5 turns out, so I figured 42 pilot would take care of that, and idle was left alone at 2.5 (I ASSume). No dyno, so I don't know if it is rich or lean, but works well. Not trying to trump Sweat, since he has been WAY more into his machine than me, just FYI.
Does it rev above 4-5k in other gears?

[ This message was edited by: rbrian_taylor on 2007-04-23 17:31 ]

sweatmachine · 04-23-2007

My bike ran like a mother F'er at this jetting:

w/ predators and airbox elim:

42 pilots, 1 turn out
1 shim on thrux needles
155 mains

If you have 42 pilots and 2.5 turns out you're probably running rich. Turn it back down to 1 turn out and start there. Keep in mind jetting is a function of throttle position, not gear or RPM. 1/8th throttle to 1/4 is the pilot jet/idle mix, 1/4-3/4 throttle is the needle, and the last 1/4 is main.

mikeinva · 04-23-2007

its ether the niddle is not high enough ,the main jet is to small or its not getting gas .check float level and tank vent .if the main jet is over 138 its prob. close enough not to be the cause.If it wont rev up at all around 1/2 throttle the niddle might need to be shimed. if it will rev up in lower gears ok,run it to about 60 mph turn it wide open for a few seconds then let off to about 7/8 throttle if it feels that it picks up power then main jet is to small.

Jimbonnie · 04-24-2007

I doubt very much that the idle mixture setting or jet has very much to do with the symptoms you described at 4,000 rpms or over. By that time you're into the needle and main jet circuits.

I've not heard anybody say that the Thruxton needles are either too rich or two lean, though some shim them and others don't.

In all likelihood you're got a main jet issue or as some have mentioned perhaps a manifold leak. How about telling us what main your running and perhaps we can be of more assistance.