Tuning at altitude

[rsuarez]

Hi, Ive tried different searches about high altitude tuning but found little. Mexico city is above 8k feet above sea level which is a little bit more than Denver, therefore any experience from Denver riders will be appreciated.

Currently my bike has been rebuilt in the engine and carbs. It runs well but does feels that its lacking top end. The settings are;

Paper filter in stock airbox
Stock exhaust (seems to be OE) but I guess they've removed the baffles as they are loud. I have nothing to compare with.
Main primary 65
Main secondary 102 (manual recomendas 98)
Pilot screw 1.5

I have good experience in tuning single cylinder 2 and 4 stroke bikes, but this is the first time I tune CV carbs. Any pointers or advice? If it was a single slide carb I would immediately say its rich on the top but don't know on these CV's

Thanks.

Ramon

[daves79x]

You are certainly too rich on the top with the 102s - the '79s were a bit rich there with the stock 98s at sea level. I'd try the stock 98s and about 1 1/2 turns on the pilot.

Dave