Triumphrat

12-16-2005

Hi, I just bought a 2005 Thruxton (at age 55!) and when one of the guys at work said it sounded like an ATV I knew I had to change the mufflers. I ordered the Off-Road ones from the dealer. They sent the wrong ones; they were for T100 Bonnie, but I noticed that there were jets and instructions included. When I got the correct ones, there were no jets or instructions. With the new mufflers it runs great, but I am concerned about jetting. There is some popping through the mufflers on deceleration. I plan on plugging the Air Injection. Does anyone have experience with this particular bike and situation? Thank you.

britone · 12-16-2005

According to Triumph, no jetting changes are required. When I installed the Off Road mufflers on my '04, the bike ran fine without any jetting changes. The sound and performance was much improved. I have also removed the air injection system.

I am currently running the Shark hi-level pipes for which I did need to make some jetting changes (which is a real pain in the a??).

Photo Album

[ This message was edited by: britone on 2005-12-30 17:38 ]

boboso · 12-16-2005

kaykay, congrats on the new bike, your going to love it. I had a Ducati 900ss that I sold a while back and finally got the Thruxton this year. I too got the Triumph Off Road Silencers (TORS) as soon as I got the bike. The popping was very apparent to me and when I removed the AI, no issues. Also, no jetting was done.

Enjoy!

Panthermark · 12-16-2005

KayKay, I have an 05 T-100 which has the same engine. Actually, "for the most part", the Bonnie, T100 and Thrux engines are the same, so don't forget to check the Twin Talk section....

Your TOR's probably came with 115's, (that's what the Bonnie TOR's come with at least), so check with the dealer to see if you are missing them.

If you are, you might as well rejet now, so you can get used to doing it. The first time is a pain in the azz, but once you do, it will be much easier the next time. Plus you will probably end up removing the snorkel and pulling the restrictor plate anyway....that along with new pipes would require 115's at least.

P.S. - Before you rejet, make sure you get new carb screws from either BC or NB. The stock ones suck, and they WILL strip. Also, with an 05 you might want to order the D-screw tool for you mixture screws. I didn't order the tool, but I had to remove my carbs completely to get a final stock screw out with vice-grips (yes, the suck that much) before I could rejet. Since I had my carbs on my kitchen table, I removed the D-screws completely (I used the little plastic wire connectors that you crimp) and sawed in a groove so that I could use a flat head screw-driver from now on.

[ This message was edited by: Panthermark on 2005-12-16 17:33 ]

CYNCRZR · 12-16-2005

TORS on the Thruxton DO NOT REQUIRE a re-jet!

D&D's on the Thruxton which are way more open than TORS do not require it either, in fact if you richen it up, it won't run as well...

But DO REMOVE THE AI as soon as possible. It will fix the popping and keep your headers from bluing all the way down past the second bend.

However, if you plan on doing anything in the carbs later... replace those crappy screws in the carb when you do it.

Enjoy your new Thrux... and when you get the urge to unleash the beast within check these forums, lots guys have done lotsa cool things.. there is more HP in the motor and as many different opportuinities for Stylin as there are owners to dream them up!

Check out my members album: Under "C" page 2, last entry!

Cheers, Cyn

Panthermark · 12-16-2005

Let me try this again....

You don't HAVE to re-jet, but you SHOULD rejet. The stock carb screws suck, so you might well get it out of the way now. These bikes come from the factory very lean plus the A.I. was installed to meet EPA standards. As I said before, in time you will probably end up pulling the snorkel and the restrictor plate...maybe even the whole airbox.

Here are some links from the CAFE Forum:

Thrux TOR's

Thrux Jetting database

Very few people run 110 mains with non-stock pipes.
IMO, D&D's and 110's would be way too lean.

Also:
When the 865cc Thrux came out, it had better (more tapered) carb needles then the standard Bonnie, hence some of the (few) differences with the 790cc engine (the 865 also has a different valve duration and a higher rev limiter)....
Engine wise, there is no difference with the 05/06 T-100 (but the Thrux does have a more free-flowing stock exhaust).

Both engines run the same SVK 36 carbs (except for the needles of course).

Again, "if" the TOR's come with 115's re-jet AND you do "slight" air box mods...rejet. If not, enjoy the road.

Happy riding and welcome to the board!

[ This message was edited by: Panthermark on 2005-12-16 22:25 ]

mjs3800 · 12-17-2005

The power delivery and Torque are not the same between the Thruxton and Bonnie motor. Different cams and headers. The same jetting techniques are not required with the Thrux. D&D'S or the more restrictive TOR's work best with the stock jets in a Thrux with airbox intact.

kwajazz · 12-17-2005

I have the TORs and the guys that installed them here in Dallas, RPM Cycles, said "no need to re-jet". And I believe them. The bike runs fine (with AI removed of course) around town and also on the track at our local track days under more extreme throttle settings (on and off the gas).

So unless you really like fiddling around (and have the time), I'd just ride it with stock jets. I used to love fidding with jets and all and had the time to do previously, but no longer.

Have fun.

CYNCRZR · 12-17-2005

Panthermark -

I have D&D's and had a stock airbox.. D&D dyno'd the mufflers and noted that any increase in jet size resulted in a reduction of HP.. it fell off.

Being a bit skeptical, I bumped the mains to 112.5 and it did lose a little crispness. And the increased mains didn't help it from 6k to redline at all!

So I finally got rid of the airbox and copied T1's setup. Now it runs like a scalded cat, you gotta be quick cuz the tach flat flies from 5,500 - 7,000 rpm...

The airbox is the restriction, all changing the mufflers does is remove the excessive backpressure they cause, doesn't allow anymore air in from the airbox. If the "stock" airbox won't let in more air, the mixture remains unchanged.
The airbox is the determining factor!

So for my .02... leave them jets alone... until you YANK the airbox.. pulling the snorkel & restrictor plate are half measures at best... send that overly large piece of plastic to the bottom of a cardboard box where it belongs!

Cheers, Cyn-

12-30-2005

CYN

i bought the D&D slip-on's for my g/f's thruxton. and i'm having a problem with steps 1-5 in the instructions!

1. remove air pipes in head, disconnect ruber hoses: do not discard copper washers

2. remove rubber hose from left carburetor vacuum port, manifold, and fuel tank

3. place vacuum cap provided on manifold port

4. plug air pipe holes with socket head cap screws provided and copper washers from step #1

5. lightly seat pilot adjustment screw clockwise and reset at 3 1/2 turns counter clockwise

i have no idea what these pieces are and where they are located! would it be too much trouble to e-mail me pictures of where this stuff is located? or at least a little better description of what they look like!!