kz 650 turbo

79 kz 650sr, was never finished by a man who was going to drag race it, he died and i ended up with the project in pieces has, milled head, and big bore kit around 700 cc range does anyone know of the kit, rebuilt rotomaster turbo/bendix zenith carb. atp turbo manifold I have it running great right now, want to get it running even better, i was wondering how to set the wastegate, the bolt being all the way in more or less boost or all the way out more or less boost i also can't get my boost gauge to work, i think its the guage, i did take off the hose and put it to my finger and it has suction, is this normal? I also think it has the crank welded? Does higher octane gas need to be run, to prevent detonation? I also own 78 kz 650B and 78 kz650sr. i have some pictures e-mail me if your interested

Screwing the bolt in will raise the boost by preloading the wastgate spring inside. If the bike is idling yes you will feel a vacuum on the boost gauge hose as the bike will run a vacuum (like any other bike) until the boost comes in. Same as putting your hand over a carb. The crank won't be welded as it is one piece as standard. Yes you will need to run race gas at high boost, how high will depend on the compression ratio of the engine amongst other things. If you hear a tinny rattle at high boost, use higher octane or turn the boost down.

I bought a new guage to measure boost, but i don't get a reading. Does anyone know whats the problem is?

Maybe the tube is on the wrong side of the turbo.

I believe boost gauges measure pressure, not vacum.
The hose should be on the carb side of the turbo, not the intake

This may be a silly question, but you do know that you are probably not going to see any boost until you are actually riding the bike, right?

It's unlikely you will see any boost when revving it up in neutral.

I'm still not getting any boost, i tried the original gauge and a new one, i did ride it and still their is no boost, their are two tubes that come off the atp manifold, the one on the leftside goes to the blowoff valve while the other should go to the pressure guage. It should be hooked up correctly, i did take off the exhaust pipe connecting to the turbo to see if the turbo was spooling up, and its spools up right away. I don't see why its not putting any pressure out, the blowoff valve is working

Can you take some photos or draw up a diagram?

I have been working with turbo cars for years. The principles are universal.

Did you ride it over 6000rpm?

Post a few pics of the blow off valve and turbo set up. Not all blow off valves are the same. Some blow off valves adjust in for more pressure while some adjust out for more pressure.
The Blake turbo unit I bought for my KZ 900 came complete with every thing BUT the valve seat for the blow off valve. I had to get one made up for it to work at all. The blow off valve shouldnt have exhaust excaping from it at all times.
If you disconnect the line going to your boost gauge and ride it, it will probably whistle (letting you know that you have boost), but if you had boost, you would know.
Daniel

Heres a pic of the blow off valve on my 900. It has 2 adjustment bolts on it. 1 is on bottom and it has another on the diagphram on the back of it.

Post edited by: dgfischer, at: 2005/11/15 09:02

No, Heres the picture.

This is the only picture i have right now, i will post some new ones tomorrow.

Post edited by: eggerj, at: 2005/11/15 17:35

Cant see your picture.

I presume it is the same with bikes, but on cars we refer to valve on the exhaust side of the turbo as a waste gate.

This bypasses exhaust gasses from the turbo to control boost.

A Blow Off valve refers to the valve on the throttle body side. This releases pressure that builds up when the throttle body closes and allows the turbo to keep spinning for longer (in turn reducing the time it takes for the turbo to spool back up when you change gears) it also makes your turbo last longer