1978 KZ1000-A2 "Barn find"

Focus on the pilot jets. Use a guitar E string or strand from a wire brush to clear them.
Steve

Yea, noticed the pilot jet on carb #1 wasn't clear. Thanks for the tip about the guitar string. I tried using a strand of a stranded electrical wire today, but it's not strong enough, and I was out of carb cleaner.

So cleaned the carbs again today. Pilot jet was completely clogged on #1, and a bit on #2. Thanks for the tip about the guitar string. It worked a treat. Running much better now. Still need to dial them in a bit. Also took off the front brake caliper and cleaned it up today. Compressed air works a treat to get out the piston, but it still scares the bejeezus out of you when it finally pops. I was going to give the caliper a coat of paint, but I'm still not sure what I'm going to do about the brake lines yet, so I just put it back on for now.

Package arrived today from Z1parts. Ordered late Tuesday night, arrived Thursday afternoon. Bunch of rubber bits.

Unsexy update.

Got the fuel cap back on the fuel tank for now, now that I have a new gas cap gasket.

Also installed the airbox with the new hoses. Reinstalling a carburator with the stock airbox will make you rethink every life decision you've ever made. I left the clamps off for now. Dreading how many times I'm going to be removing and reinstalling that carb by the time I'm done.


Also started tearing into the rear master cylinder as the rebuild kit also showed up. However, the old piston is seized inside the cylinder. Has anybody ever dealt with this problem before? For now, I've just set it upside down and loaded the piston with liquid wrench, hoping it will come out when I get back to the shop on Saturday.

Great progress. As for the MC, soaking it is you best option. Take the cap and brake line off and get your penetrating oil in every hole you can. Try heating cycles, only propane, not cutting torches. You can also strike the piston sharply, only trying to break the corrosion and not trying to push it deeper. Remember to remover the internal c-clip in the bottom before trying to remove the piston. I’ve rebuilt a few that were really stuck... patients is your friend. Once it does move it will come out. Just need the first move to break the corrosion bond.

Instead of using compressed air to remove the brake cylinder try using a grease nipple and a grease gun. Far less explosive.

Yet another update.

I had tried heat cycles and striking the piston to loosen the corrosion without any luck. After coming home for dinner, posting my last update, and searching these forums, I ended up going back to the shop. I’m the kind of person who needs to do something or I’ll lay awake all night thinking about it.

I tried the compressed air trick without luck. BUT, I have a rebuild kit with a new piston, so I ended up getting the old one out with a threaded tap. YAY! The primary cup in my rebuild kit looks a little different than the one that was in there, so I opted to re-use the original.

I was thinking my next step would be to rebuild the rear caliper, but seeing as the rear wheel needs to come off for that, I may just wait until I’m ready for new tires. Currently leaning towards Kenda Retroactives, but not certain. I’m open to recommendations.

A little tricked that I found on a search here was to roll the air ducts from the air box to the carbs over on themselves before installing the carb rack. This gives you much more room for wiggling the carb rack in place. Then use a hair dryer or heat gun to warm up the air ducts and unfold them while they are warm, one at a time and they almost naturally go right over the intake on the carb. It's another one of those "Why didn't I think of that ideas?" One more thing, warm the air ducts up a bit before trying to roll them over. It works much easier doing that first than doing it with cold ducts.
Rick H.

Well I'll be darned. I'm sure the wife is going to be upset when her hairdryer suddenly goes missing.

Pretty slick idea. Drilling and threading the piston and pulling it out.

Kaylinator wrote: ...I was thinking my next step would be to rebuild the rear caliper, but seeing as the rear wheel needs to come off for that, I may just wait until I’m ready for new tires. Currently leaning towards Kenda Retroactives, but not certain. I’m open to recommendations.

If the rear piston is seized or nearly so, it might not release pressure on the disk when the brake pedal is released. Test before Ridin' by applying & releasing the brake while spinning the rear wheel.

Re: tires, we're partial to Conti Twins in OEM sizes.

Good Ridin'
slmjim & Z1BEBE

Hopefully this isn’t coming to late but before you assemble the rear MC you need to run a 5/8 ball hone in the bore to break the glaze and give the seals a way to seat. I’ve had good luck with a 320 grit.