Re: Rejetting w/ airbox

Posted by seestheday on Oct 23, 2012; 2:04pm
URL: http://vintage-and-classic-hondas.81.s1.nabble.com/Rejetting-w-airbox-tp4031069p4031087.html

I have an 81 K.

I went from a 68 to a 75 and it made a huge positive difference.  Via a PO I was already running 105's.  That is my current set-up.

That said, my bike is probably set up differently than yours.  I have a 4-1 exhaust, stock airbox and regular air filter.  Are you running the stock 4-4's?  4-2? straight pipes?  K&N air filter or regular air filter?  All of this will make a difference.

When I was running the 68's I needed to have my air/fuel screw out 5(!) turns for it to run reasonably well.  Anything less and it was popping bad on decel and the plugs were reading lean.  With the 75's I'm now at 1 turn out which is much more reasonable.  My plugs read great (except for one that is rich, but that is due to a known vacuum leak I have to fix) and I don't have any popping issues.

If you're already at 1-2.5 turns out and it's not running too lean then I think stepping up to a 75 is too big a jump.