Big Bore Kit help

I was thinking of getting a big bore kit for my project. Does anyone know how this kit affects the power band? I know the stock motor makes 120-130 hp @95ft lbs of torque. What does the BB kit put out?

The 1300 makes no where near 120 hp... that is some sales BS from 1980's. Maybe the engines made 120 HP at the crank in a laboratory.

Real Dyno numbers from road tests were about 100 HP at the rear wheel. Here is an example from 1979.




Increasing the displacement will not adversely effect the engine output. The big bore kit is a only 6.5% increase in displacement. Headwork, cams, etc will be needed to take advantage of the 1300's potential.

Keep in mind the 1300 produces similar torque to hot v-twin. That's where the real fun is!

edit: Nick your working on a voyager, the DFI gave the big six a small power bump, but still its going to be near 100 HP at the rear tire, and that's the only HP measurement that counts!

I had my old 1300 on the dyno many years ago. It made 102 at the back wheel. I forget the torque number but it was just under the HP number. Back then I thought HP was the more important measurement but its not.

This is a great thread.

As an update I'm just waiting for my cam chain gear to arrive before tearing the engine apart.

I will add my bit to this interesting discussion. I was up near the Arctic Circle last June for our Japanese Bike Club meeting. One of the attractions available was the possibility to have your bike dyno tested free of charge.

I have ridden my 1982 KZ1300 about 15.000 miles since a complete nut and bolt restoration, including the engine. The engine has new bearings, new piston rings in original pistons, bores honed, the head straightened etc.
The only item which could be called tuning is a gentle cleaning of the inlet and exhaust, meaning removing some of the casting roughness left by Kawasaki. Other than that, the engine is stock with original parts.

The dyno result was the following:




I do not know the formula how that translates to engine HP but the bike is just a delight to ride.