750 Katana Resurrection

[Suzukian]

If you fill tubing with sand, and weld caps at the ends, you can bend it without the pipe crumpling.

[KiwiAlfa156]

If you fill tubing with sand, and weld caps at the ends, you can bend it without the pipe crumpling.

Yeah, I got the pipe and the sand. I'll use the pipe that came on the bike to get her on the road. Want to ride her to an historic bike race meet in early March.

[Suzukian]

I think that chain guard came out great. It has functional beauty to it.

[KiwiAlfa156]

Got her running about an hour ago.

A couple of problems, leaking carbs and and oil leak at the head gasket.... Think one of the o-rings hasn't sealed...

[Suzukian]

You're well on your way, even with these minor problems. You did a fantastic job on this bike.

[KiwiAlfa156]

I thought I was being so careful... The seal looks damaged and I doubt I'll find a replacement, which is a problem as I don't want to risk leaks and pressure loss. So a new gasket has been ordered.

The carb leaks turned out to be the o-rings in the fuel gallery tube between carb 1 and 2. So replaced these with the appropriate rings from my o-ring kit. Two of the drain plug seal washers were aso leaking, so I renewed these too. Didn't have the correct size washers so made some using thick gasket paper, cut with a 10mm and 6mm hole punches. Pressure tested the whole shebang overnight using the auxiliary tank hung way above the carb set. Nice and dry after 8 hours. Note to self about doing this testing before fitting the carbs over a freshly painted engine....

I'm finally getting excited about finally riding this thing. I guess extended period resto/rebuilds happen either because you're time-poor, or have no deadline or pressing need to set a deadline, or any combination of the above. Also when starting with something a bent and abused as this Kat, it's basically eating the Elephant one spoon at a time, so the focus is very immediate. And it's only now after (briefly) running it, with not much left to do, that I've started imagining actually riding it.

[KiwiAlfa156]

Well, as I write, it's Easter Sunday in New Zealand. It seemed an appropriate day to finish the resurrection of the 750S Katana. It's not road legal yet, and I don't have time today for a cheeky spin, but I've been up and down the drive a couple of times. So I'll call that the first ride .





In the past couple of weeks I've fixed the oil and fuel leaks, replaced the head gasket, set the mixture screws and balanced the carbs.

When I first ran it there was a distinct cam chain noise and not much chain slack, with the top end off I rocked the crank back and forth while pulling on the cam chain, front guide removed. It suddenly gave me extra links worth of slack . I think the chain had a static 'bubble' of slack hanging beneath the crank sprocket. As the crank rotated, the chain jumped a position. But the guides held the chain on the sprocket so the slack remained under the crank and maintained the timing relationship between crank and cams. It never turned into chain jumping teeth, throwing the timing out and trashing the valves. Reassembled the cam noise is gone. So the oil leak was serendipitous.

[Suzukian]

Very very nice!!

[KiwiAlfa156]

Very very nice!!

Thanks, buddy. Appreciated

[allojohn]

Congratulations Darryl, simply stunning. Your knowledge and skills have been a delight to follow... a lesser man would have turned away from this machine as a lost cause.

[Suzukian]

To be honest, I appreciate seeing all the work you put into this. You ended up with a beautiful bike, and you did it. It was a mess, but what you did, your workmanship and craftsmanship had me glued to this thread.

[steve murdoch]

You should be very proud of what you accomplished here.
Great looking Kat.

[KiwiAlfa156]

Thanks fellas, for your kind words, I'm very humbled by them. Every build I've done has been an exercise in attempting to do more 'in house'. Learning from mistakes and thinking about what could have better. I'm a great believer in learning all your life.

So I'm currently out on a sneaky test ride. Which has been really satisfying. Just letting her cool before putting a few more miles on her on the way home.




The chassis work was a success and she tracks true with hands off the bars. And has that on rails feeling/feedback. Engine is being run in, but feels strong. Varying the revs/load, etc. Spun her up to about 5,000 rpm. Pipe sounds awesome. I'll do video at some stage.

[Rob S.]

Just letting her cool before putting a few more miles on her on the way home.

Are oil temps high?

[KiwiAlfa156]

Are oil temps high?

No, just part of my 'running in' routine. Fresh rings and hone, recut valve seats. I like to vary revs and load (no lugging) and do a few heat cycles for everything to bed in.