Update on Header and Jetting

John Soliday johnsoliday at msn.com
Tue Apr 20 07:18:10 PDT 2010


I have an adjustable Muzzy advancer and have it at +8 degrees (never pings
even on 85 octane), have considered slotting it further just for grins but
not yet.  When I was going through the jetting exercise yesterday, I cranked
it back to +4 and the bike ran much worse, so timing obviously effects a
marginal air/fuel mixture for sure and more advance seems to work better
with a leaner mixture up here.  Once I put it back to +8 and raised the
needles one more (richer) clip is where I settled on the setup.

I thought your tach never worked with the V&H box, I thought it didn't
support that function in the GPZ.  Yes, even though your carbs are "purty"
it takes a deft touch on non-CV carbs.



-----Original Message-----
From: gpzlist-bounces at micapeak.com [mailto:gpzlist-bounces at micapeak.com] On
Behalf Of junkyardhotrod at aol.com
Sent: Monday, April 19, 2010 11:46 PM
To: gpzlist at micapeak.com
Subject: Re: Update on Header and Jetting

Hey John,

    I am currently running a 4 degree advancer, its not adjustable, dont
remember what brand it is, I put it in a long time ago.
   When I first got my gpz it had a V & H ignition box, and after I had the
bike about a month the tach quit, I found this was common with this box and
V & H wouldnt or couldnt fix it, but the box has adjustable advance and rev
limiter in it and it was set at stock rpm limit and 4 degrees advance. To
get my tach back, I put the stock box back on and with the flat slides it
wouldnt hardley run, had no throttle response and was hard to start, so I
ordered up the advancer and have ran it that way since.
    I have thought about putting the V & H box back on to see how much I
could get away with on pump gas, but the mikunis can load the engine harder
than CV type carbs at low rpms so you would have to be careful of the ping,
maybe next time I take it to the track I will take the other box and dump in
some 111 and see how much difference advance makes.

Charles/Mike do you guys have advancers in your bikes?  It's free throttle
response up here at altitude.


More information about the GPZList mailing list