Re-jetting a DT15C for altitude

[bkcoburn]

I just bought this '92 twin, Mikuni carburetor, with a .145 main jet.

I purchased the motor at sea level and operate it at 7000 feet.

At WOT it acts like it's drowning in fuel (smooth running but very little power)

Any ideas how far to neck down the main jet? .100? more? less?

[mphelle8vld]

Brownspoint lists a .145 and a .125 for that motor, try the .125 but check your plugs after running to make sure you're not running too lean.

[bkcoburn]

I'll do that. Unfortunately what I've just learned is that a more effective response is to switch to less pitch on the prop, because regardless of carb tuning I won't get the horsepower I get at sea level. and here is sit with 2 new props.