Spitting/lack of power

I've just purchased a rebuilt 1983 KZ1000P. It's only done 800 miles since an engine rebuild two years ago and the past year and a half had sat idle. It starts ok, with the odd spit back from the carb and pulls like a bull to 80 mph, but then becomes hesitant and spitty again. Lower to mid revs seem ok. It's got an after market 4-1 pipe and after market cone airfilters.

What's the problem?

Has is ever run well after installing the cone air filters (pods), and were the carbs rejetted for the pods? If not, you may be suffering from the "pods on CV carbs" syndrome. If that's the case, plan on becoming intimately familiar with the carbs since stock jetting and pods don't mix well. Ed

Sitting for a year likely clogged up some of the carb circuits. A careful cleaning of all the tiny passageways and checking the fuel level in each carb is correct, will be needed prior messing with the jets. Even then, if those are cheap Chinese pods, they may be covering air jets in the rim of the carbs.

JTTMF wrote: I've just purchased a rebuilt 1983 KZ1000P. It's only done 800 miles since an engine rebuild two years ago and the past year and a half had sat idle. It starts ok, with the odd spit back from the carb and pulls like a bull to 80 mph, but then becomes hesitant and spitty again. Lower to mid revs seem ok. It's got an after market 4-1 pipe and after market cone airfilters.

What's the problem?

Well, I'll say this sounds very familiar to me, including storming up to the peak of 80 mph!

What kind of air filters are you using? If you are trying to use the cheap Emgo "Pod" cone filters on Mikuni CV carbs, well, there's your problem, or at least one of them.

Those filters just plain don't work with Mikuni BS34 CV carbs - period. Somehow, the shape of the filter and mouth disrupts the airflow near the vacuum ports for the needle slides, preventing them from opening properly. Basically, the needle and needle jet circuits are rendered next to inoperative. This creates a very lean condition that gets worse as engine speed increases. If you must run individual filters vs., the stock air box, at least get some proper oval K&N filters, the K&N filter cleaning kit, and follow the K&N instructions. A Stage III Dynojet kit might be a good addition with those filters, too.

As for popping and spitting - sounds like it is running lean at idle also. If the carbs are clean, then check the float levels. Next try 1-1/2 to 2 turns out on the idle mixture screws as a starting point, and see if that helps....

I've no idea if the carbs have been played with as only purchased it a week ago and all the work had been done prior to me getting hold of her. The filters are cheap looking ones that's without doubt. I had a Z1000J 15 years ago with proper K&N cone filters and that didn't seem as bad, it'd pull right through the rev range with the odd spit. Maybe it'd been rejected? It's great to have a proper Behemoth again!!!!

You would be smart to go through the carbs, verify all the passages are clean and update the various O-rings. Also, check fuel level with the clear tube test before install. While in there take an inventory of the jetting and compare to the manual specs. It sounds like somebody slammed on those junky pods and most likely didn't properly jet the carbs. A set of proper K&N or APE pods are in order, along with a Dynojet jet kit. Running the bike lean such as it seems it is now is a great way to burn up the engine,

I'd check the valve adjustments and carb holders too. Also the spark advance.
Steve