KZ650 Aftermarket Petcock Installation

Disclaimer: First time poster...go easy on me. I do have a Clymer Manual, and I will post pics once I get the bike back together.

I just bought a stock 1980 KZ650-E (LTD). The lever on the petcock is broken off, the valve is very hard to turn, and the vacuum diaphram needs replacing (gas pours out when I disconnect the fuel line with the valve in the "on" position).

I've accepted the fact that replacing the petcock is probably a better approach than rebuilding or buying an expensive OEM replacement, especially if I'm planning on adding performance upgrades later.

I realize that I will need to drill the oval shaped slot in order to accept an aftermarket filter screen. I read on this forum that the best approach is to use a step drill bit to open up the hole. I was just wondering if anyone had any advice on how to keep the drill bit from "walking" resulting in an off-center condition with the mounting holes, and also a good way to ensure that all metal shavings are removed from the tank.

I thought about making a jig that would center the bit, but figured I'd check with the experts before I go reinventing the wheel.

I'm a little aprehensive about drilling into the tank without absolute certainty that I'm doing it right.

The petcock I was looking at is from Z1. It's the Custom Chrome-Single Outlet-3/8 NPT with the corresponding female adaptor plate (I need to double-check my spacing).

del

I bought the cheaper manual petcock from Z1 and the proper adapter plate. Works great.

A step drill is nice but some are pricey, I used a file. You have a dremel tool? That works too.

Remove the old petcock and place the new adapter plate in position. Mark the new hole on the tank, and get a round or half-round small file and just file the tank as needed. It won't take long at all. The shavings can be vacuumed out, or blown out with a compressor or the vacuum on reverse. I happened to have a small round magnet that I could slip inside the old petcock opening before I filed and it caught the shavings and was easy to remove. I blew out the rest the magnet didn't snag. Use a small inline fuel filter just in case.

Thanks alot Kent. I'm kind of favoring the aftermarket over the Suzuki. I also think my mounting holes are 46mm vs. the Suzuki 44mm, but I'm going to double-check. This will give me a chance to use the dremel that's been collecting dust in the garage...I'll have to let my brother know I finally was able to use his Christmas gift!

Thanks for the quick posts guys! Now I can place the order with Z1 for all the parts I need to get this new bike up and running. When it's all back together this newbie will post some pics.

i think they are 44mm if im not mistaken.