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Black Shadow jetting for altitude

tomvolk

New Website User
VOC Member
Hi All,
Now that the weather has warmed up, I find that my newly restored Shadow is running poorly. The carbs are set for sea level using the recommendations in the Rider's Handbook. The machine runs well cold, but gets worse as it warms up. I am thinking of dropping the needles a notch, but I'm a bit leanaphobic. I live at 5,000 feet, and tend to ride higher. CR= 8.0:1, stock carbs with new jets and needles etc. VOCSC spiral muffler, K&Ns. Thanks for any suggestions.
Tom
New Mexico
98F, 8% humidity
 

Tom Gaynor

Well Known and Active Website User
VOC Member
Mixture problems

The answer is to buy an RAD (Relative Air Density") meter, "as used by top tuners", when a simple formula will tell you how to rejet to suit changed conditions. These work: friends rejetted at a continental race meeting to suit the RAD determined requirements, and went down FOUR main jet sizes. Their four cylinder 500 Honda did NOT seize, in fact, it flew. Otherwise, leave the needle, and go down a main jet size. Then, after a plug chop, another if indications are positive. Manufacturer's recommendations aren't for maximum power, they're for minimum warranty claims. Over-rich performance doesn't result in seizurers, don't result in claims.
 

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