hi, my kz blew up today , MD

I figured since I wont be riding for some time now, I have time to stop lurking and say hi. I have a 78 kz650 I got a little while ago . It has pods, kerker 4-1, regular and SR tanks, clip ons, discs front and rear, gel battery , full dyna ignition and coils, hooped rear, brat stye seat, gsxr middle sets .

When I got it, the previous owner said the motor was rebuilt, but it was running terrible. I took it to my local shop, and 3 of the cylinders had very low compression. They were soaked, and 2 of them came back, one never did. My mechanic told me to run it hard, and the final cylinder should free up. Last night the bike wasnt running great, it was spuddering, and lacking power. Also sometimes my rev's would rise up to 4-5k when at a red light, but my cables didnt appear to be jammed. It was weird. Anyway, I went for a ride this morning, on the highway going about 60 and I started hearing a tapping sound on my right side. Also power felt to be lacking. I started to pull over to the shoulder, and i heard a loud bang, motor locked up, and shut off. Im really lucky this didnt happen while I was going 70 , my back wheel lock up and kill me .

Anyway, I was just about to start working on my gsxr front end swap, when this happened. The bike was towed to the shop, and getting looked at. Chances are, the motor will be tossed, and swapped with another kz650 motor he has sitting around. Id love a gpz750 motor , but theres none on the local craigslist, and even though I've seen one or two kz1000s in a 650 frame, i was told it wont really work, so a 650 motor it will be .

Anyway, no one could figure out why the revs would randomly go up and go back to normal on its on. It was also a mystery why I was burning through like 3 gallons of fuel a day . Here she is with the big tank on, pre-motor fail.

That's to bad about your bike, and right in prime riding season, bummer.
A used engine is by far the cheapest alternative, if it is good. Buying a parts bike, maybe No Title cheap for the engine would be possible. Post where your at, add the info to your user profile so everyone will have an Idea where your located. Someone may have a motor or a parts bike for ya.

You can put a 1000 motor in a 650 frame. But it will require some work. Once its in the frame you will not be able to remove the valve cover. You might wanna look into the 750 motor. I also believe people are putting 750 top ends on 650 bottom ends. Some people are also into boring out there 650 motors. But i would believe its cheaper just to get a 750 top end.

private eyes wrote: ...78 kz650...heard a loud bang, motor locked up, and shut off...also a mystery why I was burning through like 3 gallons of fuel a day ....

Possibility of gasoline having intruded into the crankcase and diluted the oil.

Would assure float valves and overflow circuits are properly functioning.

Good Fortune!