Bonneville America Forums Forums Technical Forums Performance Mods Jetting Question - Oh God - not another rookie!

Yeah.... I am a rookie when it comes to this.....
Did my searches, this is what I figure

2003 Speedmaster
Exhaust Short TOR's Not Modified

Figure I am going to do:
AI removal
Uni Filter
Polaris Bellmouth
live around 300-800ft above seal level in NJ

..... thinking 127 - 130 jets...

Opinions?

Try 125 first. The next size up is 128, but that or 130 is probably more than you need.

My suggestion is to purchase several sets and work your way up. I tried 125s on my 03 BA and with my snorkels removed with straight through TORS my bike would bog out at full throttle. Only after switching to 130s did mine improve. Don't forget, your engine is a 790 which likes to rev and makes more power than the 865 models. More power should require more fuel.

Thanks guys.....

Best place to buy jets?

....and I assume I need the D-shaped tool?

Correction: with no snorkle the jetting calculator says 126.5 at sea level, but doesn't take the bellmouth into account.

Ugh..... the more I read ..... the more I am unsure about doing this....
Can the main jets be done on the Speedy without removing the carbs?
newspeedmaster.com doesnt list a jet kit for a 2003 Speedmaster..... am I missing something?
Maybe I should just put my $$$ into suspension stuff.....

Troy, if you have a good Triumph service dealer near you, I would consider taking it to them. My dealer has a dyno (many don't) but most good dealers would be able to guess very close to what was needed for your set up. You can have them install a dynajet kit that comes with jets (main and pilot), better (adjustable) needles, and more. Getting it right can make a big difference in performance and responsiveness. Although all this sounds expensive to have done, it is not and well worth getting professional help until you feel more confident making changes yourself. You'll be glad you did. I was.

I've got a 03 with 125 mains &42 pilot. I'm gong to 130 tomorrow and try them.rudyr

Thanks Bob.....
I have spent many hours wrenching on my GTO, but just never was a fan of carb work. Just dont seem to have the finesse for that kind of work....lol
I am going to stop by my local Triumph dealer( no dyno), I have talked to the service manager before, and want to get an idea of what he can do.
He did quote me about $300 labor to install and jet up a Freak style kit, but I am not sure I want to spend a total of $700 for this type of set-up. One of the reasons I am thinking of just the Uni Filter and Bellmouth.
But part of me just wants to install a set of Progressive front springs, and a set of 440 rear shocks..... which would be easy work for me....
Thanks again for your comments..... and everyone else's also

Quote:

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One of the reasons I am thinking of just the Uni Filter and Bellmouth.

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I tried that. Didn't run good at all. You will have to rejet if you pull the snorkel and add the bellmouth.

If you do it yourself don't forget to adjust the mixture screws.

Buy the jets from a shop near you, should be able to save a little money and have them in hand right away. Honda shops and Triumph shops should have what you need in stock. Other brands use the same carbs too but seems those many times don't have the jets for some reason. Hd uses the same carbs too but they use larger mains.

Troy, I'd get it property jetted and adjusted before bothering with doing away with the airbox. Having it properly set up will make a big (noticeable) difference. Personally, I like having the airbox.

I'm totally satisfied with the performance I'm getting and although I do have the BB, (which I'd save the freak money for), I haven't seen other dyno results I like better than mine. I'm getting over 75 hp and 66 ft. lbs. of torque at the rear wheel. The figure that impresses me most is not how much hp there is at redline, it's what the bike is putting out at 5250 rpm where the torque and hp curves cross. Mine is right at 60, haven't seen many top that - freak or no freak.

The 130 or in and they really help. I have no shim's I'm going to ride it a littel and see. Rudyr

OK... I ordered from BellaCorsa 125's, 128's and 130's

That should cover me.....