Topic: What have I done....

[Patrick]

So I was in third gear, WOT. Just as I hit red line it happened.... I passed a swarm of bats outta hell.

This K0 750 is a screamer. Because of the really hot cam and the big bore, it doesn't have much torque below 4,000 rpm. At 5,000 rpm, however, best make sure there is nothing solid directly in front of you if you twist the throttle hard. It.Is. Fast. Scary fast. I'm loving it.

It starts easy and idles better that a K0 is supposed to idle. It stops as well as the rebuilt (pads, lines, orings) 1970 vintage brakes can stop it. I'm almost ready to paint. I am that confident that it will be fine.

My son already has adopted the K5, but I keep it at home and ride it every day. The K0 is worlds of fun, but I am not ready to turn it into a daily driver. First I need to replace the fork springs and back shocks. Nothing like a little wobble and bounce on two wheels at 80 mph to really focus the mind.

I think I just might take off the turn signals from the K0. Who needs them? I'll be moving too fast for cars to anticipate my moves anyway. Just a blur, really, with bats outta hell bouncing off the windshield.

And it's winter in Texas - riding season.....

Patrick

[sparty]

What did you do?  You just found the definition of fast!  I too found out what a hot cam, big bore, high HP CB750 feels like, it is, like you said, scary fast.  Enjoy and be safe.

Sparty

[mattcb350f]

Nothing like a little wobble and bounce on two wheels at 80 mph to really focus the mind.
Patrick

  well put. 

[Patrick]

Thanks, Matt. Sometimes I stumble on a good combination.

And Sparty, this engine has impressed me so much I'm thinking of pulling it, getting the head ported and putting in better rods. I wonder how much power is there.....

Patrick

[andy750]

Nice report Partick and for a moment there I thought you had blew the engine! I liked the "bats out of hell boucing off the windshield" part....very well put 

What rods do you have in at the moment? Stock? I did that after getting my head mildly ported and its leaking after a 1000 miles...I hope you have better luck!
Enjoy and keep us posted!
cheers
Andy

[RRRToolSolutions]

It's there, but it doesn't come out of hiding until the revs hit 8,000 and they'll hang around for almost 2,000 rpm.

These are the readings from my butt dyno. The front will start lifting around 8,000 and starts dropping at the 10,000 mark. Based on what I know of torque and horsepower - I'd guess the peak torque is made in the 8,500 area and falls quickly after 9,500. You can work backwards to derrive at this. Knowing horsepower is torque x rpm/5252 - you know that the rpm side of the equation is there at 10,000, but the front falls fast afterwards, so the only thing missing has to be the torque. A quick shift to the next gear at 10,000 puts the bike back into the meat at 8,500.

I find this to be very livable and practical. A heavily modified two stroke on the other hand is a pain in the butt to ride. It has a powerband about as wide as a gear change and nothing on either side. When you say "what have I done? it could be 10 times worse. I've been there.

Gordon

[Patrick]

I know what you mean about the two-stroke power band. In my misspent youth I raced a Bridgestone 200 that was heavily modified. I had the head ported, put on way oversized carbs and cut back the rotary valves so that instead of shooting fuel for about 120 degrees of crank spin they were NOT shooting fuel for about 120 degrees. That bike was an absolute screamer - between 10,000 and 12,000 rpm. Below 8,000, mopeds could pass me. If I revved over 12,000 rpm I would blow the rotary valve seal - a 25-cent part that took six hours to replace.

But for that 2,000 rpm band nothing could touch that little sucker. Nothing.

Patrick

[RRRToolSolutions]

Patrick, I've got a 1974 H2 that is heavily modified - I'd always wanted something I had to respect. Now every time I look at it - I ask "what have I done?". It's no fun to ride, it's not safe, and is not sellable. It's money I I could have put into a nice Z1 that could be ridden. The Kaw riple bug will bite you and you either love them or hate them - but you always love hearing stories that surround each and every one.

Back to your 836 - these are so practical and deliver very respectful performance for 30+ years old machinery.

[Patrick]

My Bridgestone was a '69 that was built specifically to beat a Kaw triple 400. It destroyed it. Sadly, the bike could only race. You had to run it WOT all the time or it fouled the plugs within 10 to 20 miles. That's when I learned you can clean fuel fouled plugs exactly one time. When they foul the second time they are shot. No riding around town on that little bike. It was only good on a half mile oval.

One interesting thing about that Bridgestone. Because of the balance of the frame and motor the front end did not come off the ground, no matter what. It made it very effective off the line. That's where I won most races.