Husky jetting specs

I have the original jetting specs for my 78 390 as part of the original Husky Manuel. Does anybody know if Husky published those jetting specs to be used at sea level?

Yes, the factory jetting specs are for sea level. Also the fuel mix at 4%.

Marty

Hoping to piggyback on this thread a little. I'm taking the Bing off of my 77 250WR and putting a Mikuni 38 on. What jetting and how many turns out on the air screw would you recommend for a base line? I'm thinking I could go off what my 1981 manual says for a 250 which is a 430 main jet and and a 45 pilot jet (I have a 47.5 pilot in there now because it's what I had)? I I live only a few feet above sea level.

Did your 77 come from the factory with a Mikuni? I'm not sure what year they changed. If it did, there is some place you should be able to look up the stock specs. My 78 390 specs are 430 main, 45 pilot, 6DH3 needle, a 166 series Q-8 needle jet and air screw out 1.5 turns. Marty sez those specs are at sea level riding. I called Sudco (for Mikuni parts in Colton Ca.) and they agreed. You can also get a very handy Mikuni "Pocket Tuner" from Sudco that determines main jet size for elevation and temperature changes once your dialed in.

The main jet size increased in 1979 because the new airbox flowed 3 times the airflow that the 1978 airbox could move. I found that out in a test on the 1979 390CR , It initially seized a few times on the old jetting and did not resolve until they changed to a 480 main jet.

Jimspac, very interesting information. I've got my 78 almost completely sorted out. At track elevations from 1500 feet to 3500 feet the bike was just blubbeing from a quarter throttle to WOT with a variety of jet sizes from 400 up to 430 and a variety of needle positions. I changed the needle jet from the stock Q8 down to a Q6, and everything came together.