Stage 1, Stage 2...

I just bought and finished breaking in a 2005 Yamaha Road Star 1700
(first bike). I installed a set of V & H Long Shots and took out the
baffles. I have not altered the air intake box nor have I re-jetted.

Before I take any other steps to enhance the engine performance, I
would like to become a little more educated about the different stages
I see discussed. Can anyone point me to an article that describes in
technical terms what exactly each stage is, and what is trying to be
accomplished in each one.

Feel free to recommend an air box, and why you recommend it. Thanks.

Carl

 

Does that machine have carburetors? I'm not going to look it up. If it
has carbs, I would recommend just going up about 1 or 2 sizes on the
pilot jets and adjusting the pilot mixture screw. If it has fuel
injection, buy a Power Commander and download new FI maps and program
it.

All that Stage 1 usually just corrects the EPA lean mixture and gives a
little better off-idle throttle response. Stage 2 is for riders who
ride at high speeds on the street and back roads, and Stage 3 is for
competition riding on a race track where you are running full throttle
and high RPM for long periods of time.

In the USA we are usually riding from town to town (or in town all the
time) with just some high speed sprints for a few miles and the engine
doesn't have time to get all that hot. The whole idea of re-jetting is
to add extra fuel to keep the engine cool. If the engine doesn't get
hot from hard riding you don't need bigger main jets.

Keep your air box. The air box is more than just a place to put your
air filter. It's a tuned cavity. Even professional motorcycle engine
tuners used to remove them before they found out that air boxes are
Helmholtz Resonators. Google that up.

A Helmholtz type airbox helps smooth out mid-range flat spots by
providing very low pressure air to counteract air that's flowing
backwards from the exhaust system, through the open exhaust valve,
through the combustion chamber, out the open inlet valve and all the
way to the carburetor or throttle body intake during the valve overlap
period. This reverse flow causes a flat spot where the engine can't
suck in fresh mixture. The Helmholtz resonator compensates and works
over a wide RPM range.

 

Thanks for your input. Yes, this machine *is* carbureted - with one
carb.

I Googled the Helmholtz Resonator, and can appreciate your comments
about the stock airbox. Considering that there are a number of
aftermarket airboxes out there - all of which make claims of increased
horsepower, etc. - I would like to hear from anyone who has tried one
of these products. Do you really notice an improvement in engine
performance while sacrificing the benefits of the stock airbox?

 

An Asian cruiser? Just ride it. They pretty much maximize the power from the
factory. You could spend hundreds, or even a thousand or two before you'd
see any measurable impact on HP or torque. If you do decide to proceed, do
a baseline dyno and a post mod run...if you dare.