KZ1000 1981 Delcevic 4 into 1

[Foxfix]

I have a 1981 KZ1000 CSR which is all 100% standard spec with BS34 Carbs, Airbox and Air Filter etc.
I have fully reconditioned the carbs and all is good.

It also had a brand new Delcevic 4 into 1 Exhaust (Straight Silencer Type) fitted when I bought it which is "ok" quality and requires no re-jetting or alteration to the bike for running.

The bike only has 9000 miles recorded and runs very, very well in everyway from starting, idle and up to to the redline. Pulls like a train and plugs are a nice light chocolate brown, which I always aim for.

I have never had any bike with a Delcevic System fitted and would be interested to know if anyone out there is also running one ?

I have found on carb set up (Mixtures) to prevent "popping" on overrun, I need to set the mixtures at a minimum of 3 turns out, which in my experience for a standard bike is more than the usual 1.5 to 2.5 settings I have found in the past for a typical Z1000.

Question.............has anyone else with a similar bike and exhaust with standard set up found the same applies ??

Thank you.

[Al]

That would be about right. Standard is around 1 1/4 i think. Long time since the CV's with a 4 into 1 but they were averagely 3,.... from 2 3/4 to 3 1/4 and thats with the colourtune. Not all the same but there it is. This avoids; spitting back through the carbs when cold, hanging throttle and popping on the over-run as you have. Those things though are right on the cusp of max power or max output. You are off-setting to avoid the downsides of modern fuels in old engines.
Didnt help having the single K&N filter and of course modern 'petrol' has lower BTU's, different viscosity different molecular weight and different Octane rating number, not that the latter would make any difference here.
If you have brown plugs you are a little rich as in 'not complete combustion' but with an aircooled its better to be safe than sorry.
AL

[Foxfix]

Thanks Al,

You have confirmed what I thought would be the case.

I am going to try some wadding on the baffle to see what effect that has as some say it can reduce the popping (which would be there regardless) just not as audible with the standard system, but if no better, its just stay with the 3 turns out and run rich.

Thanks again