Z1B Refresh for 2022 Events

[kawasaki_man]

I've started a refresh on my Z1B so that it should be in good running order to attend as many Z1 50th Anniversary events next year as possible. The plan was to have a rebore & new pistons to +0.5mm on a spare barrel that I had purchased some years ago and had no broken fins. At the same time I would sort out / replace worn cam idlers and cam sprockets to hopefully reduce engine rattle.

The rebore and pistons were done a year ago, however I decided to replace the front cam guide and that's where the problems started. The recessed crosshead screw had been glued into the barrel and its removal revealed the boss in the camchain tunnel to be badly cracked. I tried to effect a repair that did not work and the boss parted in two. Fast forward until August this year. I started a dialogue with Dave Ennis (Buzzard) to see what might be possible. The problem was gaining access to the boss area to build up weld. The first part of the repair was done by a coded aircraft welder that Dave knows, this was then finished by Dave with milling, drilling and tapping in his workshop. I'm happy to say that the barrel arrived back with me on Tuesday so the Z1B refresh is finally back in motion. Some pictures of the dilemma and solution!

1. Initial damage to camchain tunnel boss

2. Damage made worse...

3. Buzzard at work

4. Worked completed on the repair

[kawasaki_man]

The strip down of the bike started at the end of September, removing all the usual parts to enable the barrel to be removed. Engine will remain in the frame. I decided to replace the stator since this was the original one, noticed one wire was showing bare wires and also hoping that a new stator will help to stem the usual oil leak around the rubber seal for the gen wires.

Once the head was off I was able to inspect the cam idler sprockets and found the front one had lateral movement to the extent that the sprocket would slide apart, the result has been some groves being cut in the camchain tunnel.

damage from idler sprocket (2).jpg (208.32 KiB) Viewed 8730 times

A couple of days ago I managed to remove the old block which has had a couple of broken fins ever since I have owned the bike. Removed the pistons (standard size) and inspection showed some carbon build-up on 1 & 3, 2 quite light and 4 almost no build up.

[kawasaki_man]

Cleaned up the repaired barrel, heated to 150 DegC and the liners dropped straight in. Should be ready to start engine reassembly shortly.

oven (2).jpg (197.46 KiB) Viewed 8646 times

block (2).jpg (208.51 KiB) Viewed 8646 times

[Philippe]

Hi kawasaki-man

I see you're doing a great job! Make sure you replace every part of the distribution system(sprockets, guides, chain, tensioner, roller, and rubber blocks,... ). Don't forget anything! The engine will run very smooth afterwards.
Your bike is worth every penny you invest in it.
Keep up the good work.
Greetings from Belgium
Philippe

[kawasaki_man]

Thanks for your encouragement and words of advice Philippe. I often look through your posts on your projects for tips and technique, very helpful.

Today I worked on the installation of the new IMD pistons, I found the circlips quite a bit stronger and thicker than the kawasaki ones. I needed to develop a better technique for putting them in. Easy to practice on the first 4 circlips when pistons are still on bench, it seemed easiest to have the free end of circlip positioned over the cut out in piston and then push the circlip around the grove once installed. It worked OK and now the new IMD pistons, rings and gudgeon pins are all ready for the barrel.

As per Philippe's advice I have the cam parts purchased for some time already and the other day painted some easy to see marks on the APE sprockets, otherwise seeing the marks in a dark garage can be a bit frustrating.

[r3sc]

Hi,

That motor is looking great. I’m just on with stripping my A1 and my engine needs some serious cleaning.

Could I ask, who’s cam chain hardware did you buy? Did you get the kit from Zpower?

Keep up the good work.

[kawasaki_man]

Hi,

That motor is looking great. I’m just on with stripping my A1 and my engine needs some serious cleaning.

Could I ask, who’s cam chain hardware did you buy? Did you get the kit from Zpower?

Keep up the good work.

I purchased the adjustable cam sprockets (APE) and the top idler gear assembly(APE) from Suzuki Performance Spares in Wisbech.

The rest of the cam parts came from Z-Power, Kawasaki parts or pattern, other than the 2 cam idler gears that are Liska and slightly different design. (Photo attached)
I hope this helps and your A1 rebuild progresses smoothly.

liska sprocket (2).jpg (68.92 KiB) Viewed 8580 times

[kev edwards]

Nice bit of progress, the Liska type sprockets are noisier than the stock type, i re-furbed my own.

[kawasaki_man]

The job that I least like is putting the barrel back on, always makes me nervous. This time I used the special Kawasaki tool that I recently managed to find on ebay, however the one I have is really for the 1000cc engine, but with care it can be used. As usual first attempt I did not have it done up tight enough, so it tends to fall down a bit letting the rings come free. Second go and a bit of prodding got it done. The only advice I can give is go slowly and if there is any resistance check if a ring is not going in the bore.

First photo with the compressor jig, second photo job done and engine rotated to check all is ok.

[kawasaki_man]

How time flies, I've managed some time working on the bike over the past few days, cleaned up the head, fitted the new cam idler sprockets and I am using a Vesrah gasket set for this rebuild. Annealed the copper washers and then fitted the head and it is now torqued down. Next task is to change the cam sprockets and get the cams and timing set.

[r3sc]

Your barrels and head look really nicely cleaned.

I hope mine turn out as well!

Spot on!

[kawasaki_man]

Decided to crack on with camshafts and timing today. Removing the old cam sprockets was difficult since the securing bolts had been treated to permanent thread lock. Needed to get a large wrench out to stop the camshafts turning. New sprockets fitted and treated to non-permanent thread lock. Installed all the relevant shims with a few size changes to keep things in the 0.1 to 0.15mm range. Set the cam timing at TDC 1&4 and fitted the cam caps and torqued them down, then on with the new top idler. Once this was fitted could rotate the engine to check that all was timed correctly, happy to say that after one rotation of camshaft the marks on sprockets and crank TDC marks were still lined -up. Happy with that outcome. Also can check the cut outs on the end of the camshafts are level with cam cover surface and point outwards, a quick visual reference.

[kawasaki_man]

I'm just completing the refresh story...I got a bit sidetracked with a bike trip to Turkey, round trip of 6,000 miles in May & June of this year.

The engine was largely completed last winter, the remainder of the jobs to do in spring where to replace front and rear wheel bearings, repaint front hub in correct colour and change both tyres for Avons. As usual things never go to plan! I had a problem with one damaged front spoke when removing it so ended up replacing all the front spokes. I also found a minor leak on the front brake which meant having to replace the brake piston which had a small pit just where the seal was sitting.
A few pictures of the work in progress below:-

[kawasaki_man]

1st May 2022, bike completed and ready for first start, fuelled up, new fuel hose fitted with inline filters. The carbs were leaking like a sieve on the T pieces. (The carbs had not been touched since last ride 2 years ago!). Quickly ordered and fitted the 2 new T pieces and fuel leaks banished. Ready to start the bike now on 10th May (i'm off on the Turkey bike trip on 16th May, on Yamaha Tracer), so not much time to get bike sorted since I've booked the bike to the Crich Tramway event!

Z1B was OK on the first 18 mile test run, just needed to sync the carbs as bike was running a bit rough, This would finally get done on 28th June and bike was ready for Crich event just.

Turkey bike trip (16 May to 27th June)
In Romania on the Transfagarasan Highway

Back in time to attend the Crich Event on the Z1B

[chrisNI]

Good job bike looks really well