Bonneville America Forums Forums Technical Forums Performance Mods Where to start?

Just bought myself a completely standard 2004 America. Seller has short pipes to send me, don't know the make. Plan is to ride it till the winter and then start on some performance mods. Am able to do most work and any advice on where to start and suppliers to use would be appreciated.

The question is How deep are your pockets -or- how much do you have ear marked/willing to spend for "upgrading"?
Start out with the easy stuff,carb filter change, tune and pipes. TTP tune upgrade...
AS Tim the Toolman says... MORE POWER!

And don't forget about the suspension...How old are the tires?

Pockets aren't that deep but probably willing to spend up to £1000. No idea how old the tyres are but they are Bridgestone and don't fill me with confidence. They will do till the winter tho. 😎

Well, if your not confident with the tires, change them! Safety first, then performance... but if you're going to install pipes realize that a tune-up will be mandatory so if you want to install air filter/pods, do it before the tune-up just to save your time and another tune-up.

Given your location, TTP is your best bet.

If com-pletely stock I would say the first change should be to remove the air injection. Then pipes and filtration to match and rejet the carbs to match. Don't forget to adjust the mkixture screws.

Thanks that was just the info I wanted. Plenty of experience modding other bikes so happy to do carb or engine work. Just have no knowledge of what's best to start with on the triumph twins.

I usually start with the intake and exhaust. Any other mods won't be as effective unless you are getting as much air/fuel through the engine as possible.

Jim, have a read of the America/Speedmaster section HERE. The dyno's are all from EFI bikes so the figures from a carb bike will be a little less, but the percentage changes in torque/power from mod to mod will be about the same.

We usually recommend that America/Speedmaster owners keep the airbox in place unless you're carrying out internal engine mods, otherwise you can lose too much mid range torque which takes the fun out of riding a cruiser.

I'd say it really depends on what kind of riding you're after. If you're happy with its current power, then get rid of those Bridgestones and stock suspension! TheDog is right, get rid of the air injection and open up the carbs and exhaust a bit, you should be able to do that fairly cheap. I had a long term goal with mine, now my motor puts down 80+ hp at the tire. But it gets spendy. There are a lot of options available, read up and decide how far you want to go.

Follow the jetting calculator from Dinqua and you should like the performance. I drilled out the back baffle closed the air induction and opened up the intake and the numbers worked well for the new jets.

Hole saw, take out 2 stages, runs sweet and sounds perfect (2005 TBA).