Bonneville America Forums Forums Technical Forums Performance Mods Pilot jet question

I'm currently running an '04 speedy with the top snorkle removed and JC Whitney pipes. Current jetting is 130/42 3.5 turns. 1200ft elevation

I just ordered some Thruxton needles and am going to drill out the bottom of my air box. Dinqua's calculator says I should be set up just about right, but I was wondering if you would recomending upping my pilot jets to a 45 from the 42.

Thanks,

Bob

For $13 bucks and an hour of work, try it? 3.5 turns out on the idle mixture jets is a lot.

Did some huntin' and found them quite a bit cheaper through Bella Corsa... CVK Jets $9 shipped.

even cheaper through a Honda shop, $3 no shipping.

You might find that the bike runs pretty nicely with the 42 pilot and the TBS needles. If you go up to the 45 pilot, you might find the TBS needles a little too rich. But give it a shot and see how she runs. I went up to the 45 pilot jet and had to take my TBS needles out and replace them with a shimmed stock needle. Keep playing with it and you'll eventually get it perfect.

I finally changed my setup to 125 mains and Thruxton needles with one chims each. Didn´t change pilot jets (which I believe are 42 stock). Already had K/N filter and replaced the snorkel with bellmouth from Jenks Bolts. The A/F is 2 1/2 turns out. Running long TBike pipes.

Hadn´t have a chance to ride with that setup yet, but she runs nice on idle and trottle respons feels right.

I read the instructions at Dinqua site that said not to change the pilot jets unless you live in high altitudes. I live at sea level. With this much experience on carb jetting I decided to follow the instructions and use the jet calculator to get the main jets right instead of going solo on this one. My first mod ever on carbs so I hope I did it right.

FYI, stock jets are 40. At least in 2001 and 2002, they were.

My stock jet in my 04 and Wendy's 04 were both 42. Also you can burn more fuel at sea level than high altitude due to the atmosphereic pressure in effect more air in a given volume so you can run a larger jet at sea level than at high altitude.

My bike is also 04 so I quess that 42 is right then.

The calculator gave me the result and without any better knowledge I had no reason not to believe it.

Also installed the flush mount gas cap and the Pingel petcock (that gives the bike more fuel since it´s "high flow", right?).

The high flow petcock will only let as much fuel get to the carbs as required. It doesn't make the bike use any more fuel or run any different than with the stock one, it just allows fuel to pass as fast as the carbs can shoot it into the motor.

the pingel won't dribble, if your float needles do, you won't puddle.

Yes I know the engine cannot burn more fuel only by changing the petcock and that wasn´t the reason. The reason was that the original petcock started to stuck especially if I didn´t ride for awhile so I wanted to change it anyway. This I think is a known issue with the stock petcock. Sorry

I got one because it's pretty!
See my signature line!

I don't remember what models used the same carbs as we do but I do know for sure some did. HD, Yamaha, and Suzuki did too. HD tends to have too large a jets in stock because they feed a larger cyl.

Went for short ride today and I must say the bike runs like a dream. Still popping some on decel but has more low and mid range torque. Running great and I was already thinking about changing front sprocket one tooth up (to 18). So the Thruxton needles work very well. I'm so happy with the result.

The Pingel petcock has a minor leak I have to take care of. Think it's the screw holes but didn't take closer look yet.