"bob" <robob68 DeleteThis @earthlink.net> wrote in message
news:1117117932.718901.139670@o13g2000cwo.googlegroups.com...
> Just how important is it, really, to rejet the carbs when installing
> slipons?
>
> I have spoken to several people with VSTARS (mine's a 650) who've
> installed pipes and not rejetted. The only thing they report is some
> backfiring...which I already have on my 2002 with stock pipes.
>
> I'm thinking about trying it along with K & N's new (to me at least)
> high flow replacement filter element.....about 50 Bucks vice the $150
> it costs to replace the whole assy.
>
> The dealer tells me (and why do I grab hold of my wallet whenever he
> speaks???) that the bike would not idle and be hard to start.........
>
> cheers
>
> bob
>
It is fairly simple---if you are just opening up the exhaust the intake will
restrict the amount of air that will flow through the carb which keeps it
close to 'stock' so the carb doesn't need changing. Same thing is true if
you only change the air filter, the exhaust will restrict the maximum amount
of air that will flow. BUT if you change BOTH you will be going into a realm
that MamaYama did not allow for in the original carb/jetting setup.
Doing both will give you more available power because the engine doesn't
have to work so hard to suck in air or push it out---leaving more available
horsepower at the rear wheel BUT the increased airflow will be outside the
parameters of the way the engine was set up to begin with which will make it
run lean with all the other problems that go with THAT!
A friend ported his V-Star 1100 engine and intake, put on V&H longshots and
a hypercharger, all at the same time without re-jetting. the bike was
impossible to start, ran like crap when it did and 'blued' his pipes in less
than 300 miles. BUT when he got the jetting done it started better than it
did when new, ran like a striped ass ape AND got better fuel mileage than
stock.
I'd say it is worth the effort.
You can do it yourself, check out <a style='text-decoration: underline;' href="http://www.delphiforums.com" target="_blank">www.delphiforums.com</a> there are forums for
Roadstars and V-stars with very knowledgeable people willing to teach ya
how.<!-- ~MESSAGE_AFTER~ -->
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