KZ650 SR

Morning, just joined, looking for advice.
I've had a KZ650 SR (1979) for about 8 years, it was a basket case, I got it running about 4 years ago and then made the mistake of messing with it!
The engines now been honed and rebuilt new rings etc, all good.
I took out the air box and put individual filters, plus. 4 into 1 exhaust so I fitted a dynojet stage 3 kit, jets and needles.
I fitted a Boyer brand den electronic ignition.
Issue : I'm struggling to get it to run, when it starts it works well until the throttle is opened and then it dies. When I take it off the choke it dies.
I guess the carbs set up needs a good looking at (way too much air for the fuel), does anyone have any recommendations as to needle positions etc. etc for me to start?
Much appreciated guys, great site.

Start with the setup described in the instructions that came with the Dynojet kit. That will get you very close.
Have you confirmed that the fuel level in each carburetor is within factory specifications?
Are the filtersa respected brand - APE, K&N, Uni? If they are cheap filters, they may cause you some grief.
Are the carburetors fully seated in the carb holders? Are the carb holders old, stiff and cracked? Perhaps leaking where they should seal against the engine?

When the engine was apart, were the carburetors completely drained and sitting on a shelf? If they had fuel in them, the pilot circuits may be clogged with dried fuel residue.

Thanks for that, the filters are no brand, I'll get something more suitable, the carb holders look OK but are hard, I'll order some new.
I'll check the fuel level in the carbs and have another go.
Much appreciated the feedback, I'd got to the point of throwing a tarp over it and moving on, I'll have another crack at it.

+1 on checking the carb holders for leaks. I would also make sure to check the vacuum stems on the carb holder and make sure they are sealed as well.

It sounds like your pilot circuit is clogged. Or at least that’s my guess as it will idle but won’t rev, had the same issue on my ‘79 SR when I first got it.



On a side note with pod filters, make sure they don’t cover the orifice on the intake side of the carbs. (Assuming you have the stock carbs) Some pod filters have a lip inside them that will cover those holes and cause tuning problems, but can be solved with careful clearancing with a utility knife.

Great advise, im fitting a starter clutch kit this weekend and will have a look,
Cheers John