Triumphrat

Frankielosmilzo

hi, I'm writing from Italy and I say first that my English is not very good. I have seen that in this forum are all very good with the bike and I wanted to ask a question.

I have a Bonneville 790 with removed Air Intake System, Uni Filter, Snorkel removed and mufflers Debaffled.


what size of Main Jet should I mount?

I think that the ideal should be around 120/125 with Pilot Mixture Screw turn 2.75. Is it correct? I hope you can help me.

Sorry for my bad English.

Baltobonneville

120 should be close to the right size.

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Marty
2005 Bonneville Blue 790cc, AI removed, Staintunes RC, Unifilter, no snorkel, 118/40/Thrux needle/1 shim/3 turns, tachometer, Ikon 7610s in back, Ricor Intiminators in front, Pirelli Sport Demons, D9 gauge panel.

RedBird

I agree....120 should be real close to the correct size for your current modifications.

Don't apologize for your English--it is better than mine.

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Larry
2003 T-100 (790cc), NARK, NH Togas, 8100 rpm rev limiter, 158 main jets, 42 pilot jets (less than 1 turn out on pilot screws), stock needles--no shims. 13 A/F ratio from 1100 rpm to 4000 rpm; 12 A/F ratio from 4000 rpm to 6000 rpm; 13 A/F from 6000 rpm to 8100 rpm.:D
2007 Tiger 1050--White:D--SW-Motech crashbars, Skidmarx rear hugger/chain guard, Calsci +7 windscreen.

Frankielosmilzo

thank you:

bonnieowner

Be sure to check your pilot jet while you are in there. Use a #42. This will have a very positive effect on your midrange. Your english is fine.

Frankielosmilzo

hi, in italy we have a lot of problems to find pilot jets for mikuni...
i'l try to regolate air mixture screw... for now i can't do anithing :/

thank you so mutch

Sheepdog

Frankie,
The Triumph uses a Keihin carburettor...not a Mikuni. It is the same type as used with several other machines, including the Kawasaki KLR650. You may have some luck finding the appropriate jets at a Kawasaki dealership. Also, several aftermarket parts dealers in the USA sell Keihin carburettor parts by mail. Try BellaCorse (http://www.bellacorse.com/bce011-14.htm) or NewBonneville (http://www.newbonneville.com/html/ke...etor_jets.html).

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2003 Bonneville T100 and 2007 Moto Guzzi California Vintage

Baltobonneville

You probably don't need #42 pilot jets with your setup.

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Marty
2005 Bonneville Blue 790cc, AI removed, Staintunes RC, Unifilter, no snorkel, 118/40/Thrux needle/1 shim/3 turns, tachometer, Ikon 7610s in back, Ricor Intiminators in front, Pirelli Sport Demons, D9 gauge panel.

RedBird

I agree with Marty in the post above. The 790 should run fine with the stock 40 pilot jets. Many run 42 pilot jets in the 865's, and I have no comment on that; however, I believe the 42 pilot jets are not needed for the 790 unless one is running header pipes without the crossover pipe. When I ran my bike with this type of header, the 42 pilot jet was needed; but, it is not needed now with the airbox removed and NH Togas. I still have the 42 pilot jets in but the pilot screws are adjusted less than 1 turn out.

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Larry
2003 T-100 (790cc), NARK, NH Togas, 8100 rpm rev limiter, 158 main jets, 42 pilot jets (less than 1 turn out on pilot screws), stock needles--no shims. 13 A/F ratio from 1100 rpm to 4000 rpm; 12 A/F ratio from 4000 rpm to 6000 rpm; 13 A/F from 6000 rpm to 8100 rpm.:D
2007 Tiger 1050--White:D--SW-Motech crashbars, Skidmarx rear hugger/chain guard, Calsci +7 windscreen.

bonnieowner

Not to be argumenitive, but the guys at South Bay Triumph (British Customs) told me that when any mods are done to the intake, they always recommend going to a #42. The main jet is the one that requires more scrutiny because of the many different exhaust systems available, including simply removing the baffles on a stock set of silencers.