Z1 as a project?

[royhall]

Fantastic job Dave. And to think I very nearly bought that before you. I didn't because I thought 9k was too much. Who's the fool now then, ME. Beautiful looking bike.

[kevski]

That's a great job Dave, credit to you, keep an eye on the tap i had three in a row that let by, i put a Pingel on in the end.

[Andrew-S]

Stunning job Dave, and I'm sure it'll become your favourite child very soon! 

[Bryanj]

I remember those well, did quite a few accident jobs and always enjoyed the test rides

[MrDavo]

Thanks for your comments, much appreciated.

Fantastic job Dave. And to think I very nearly bought that before you. I didn't because I thought 9k was too much. Who's the fool now then, ME. Beautiful looking bike.

I thought £9k too much too Roy, which is why I paid £8.5k!! He was asking £10k at the time, no offers. He dropped to £9k no offers later. I persuaded him that a lot of people were selling toys first to make ends meet during Covid (him included), depressing the market. He had priced up the absent parts, he reckoned another £3.5k to finish it, which turned out to be about right, including the exhaust set. So it owes me around £12k, still a lot of money, but a sight less than I could probably sell it for, I certainly couldn't buy one as good for that.

Test riding showed the tickover to be 'chuggy', with a lot of noise from the clutch in neutral. Time for a tune up.

I had a go at strobe timing and synching the carbs yesterday. My cheapo Gunson neon timing light proved to be utterly useless, I couldn't see any marks at all, even after I painted them yellow! My mate Mark says you can use these, but only looking close up in near darkness. A year or two back, an old chap I know who used to be a rally mechanic gave me a bunch of his old tools, as he was moving into a flat, he wanted them to go to someone he knew would use them. A root around in the garage revealed an old Crypton Powerflash he'd given me, with 12v leads to a battery and an inductive pickup. Once I had it all worked out, what a difference! It turns out my static setting was a touch advanced, we'll see what the difference is like when I go out next.

Mark lent me a big fan, and a set of vacuum gauges. Here we are set up, with the chain oiler tank pressed into service again.



I got the 4 carbs about equal at a steady throttle, however I seem to have adjusted all 4 off their stops, as the idle adjustment screw had a gap that it didn't have before. The adjuster screw on #1 carb is a bit broken, I'm going to order a new one, but it may have to come from the USA. I've got them as near as I can for now, I'll have to do it again when I change the adjuster.

[royhall]

You may have to adjust them all back to a bit to get it back on the idle adjuster. This is the really hard part of a restoration getting everything working at it's best. Can sometimes take weeks of adjustment and trial to get it right. Keeping good notes of where your baseline start point is then what adjustments you made from there compared to what the trial outcome was can be an enormous help.

[MrDavo]

Yes, I think it might take a lot of faff and adjustment to get it spot on, but already it’s running so much smoother. No more doom laden clatter from the clutch at low revs, so that’s a result.

It ticks over, but only with me holding the throttle open a tad. Let go and it dies. Come to think of it, I had several bikes in the past that were always like that, particularly the ones that had full race cams etc. It’s the first time I’ve ever synched carbs myself, but I’m pretty sure that I should have left one carb alone and adjusted the others, as it is they are now all off their stops. I’d turn them all back an equal amount and have another go at vacuum synching but as one adjuster is broken I’m going to do it again once she is run in. By then the replacement adjuster should have come, unfortunately I could only find them in America.

Having fun putting the miles on in the good weather, now at 260 miles. Today I had my first cheek clenching encounter with a big bump on a corner, but that’s 1970s suspension for you.

[MrDavo]

Well my running in was going well, 350 miles in a week after getting the Z1A back on the road after a long sleep as an unfinished project. The bike is running perfect (apart from a poor tickover when hot sometimes) but I think my valve oil seals are shot.

Saturday I did 100 miles running round the Peak district, I met a lot of people who have had a zed at some time in the past. When I got home, I noticed, to my horror, a load of oil in the ends of #1 and #2 pipes. Also, the oil level had dropped from Max to Min in only 100 miles, a bit steep. When I started from cold, I noticed a puff of blue smoke, but absolutely none during riding. I hoped it was due to overfilling - I had topped up to the top mark in the sight glass, however I would expect some oil in the airbox, and there was none.

Sunday I didn't top her up, I cleaned out the pipe ends with paper and brake cleaner, and went for a test ride. This was the result:



The upside is that those two pipes will never rust from the inside. I should watch for drivers behind me putting on their wash / wipe. Its also on the rim, chainguard and the back and front of the number plate.

I'm guessing that, as the engine was rebuilt an unknown time ago, that the valve oil seals have perished and failed. When I stop on a ride I use the sidestand, which probably pools oil on that side too. If it were bores or rings, I'd expect smoke and oiled plugs if it were using that much oil. the fact it's not oiling plugs makes me think specifically exhaust valve seals, the oil is going straight into the pipes without being burned.

I've seen the Suzuki Viton seals recommended on the Z1OC forum, I'll order a set, also I need a Vesrah top end gasket set, can anyone point me at ones which have the split head gasket (typical Ebay blaggers are advertising sets with single head gaskets as fitting all 900s), if not I can get a full set from Z Power. Never had the head of one of these before, I have a shop manual, but there may be questions. I'll check the valve clearances before I take the head off, to see how accurate they were and give me a heads up if I need extra shims.

[Bryanj]

No more difficult than an sohc except you have to count the cam chain links between cams, we always used to set on tdc and paint mark the links where the cam marks are

[MrDavo]

Yes, and the upside is not having to take the engine out, as you know Z1 top ends will come off with the engine still in the frame.

[Bryanj]

Do you know if it wasre bored?

[MrDavo]

Do you know if it was re bored?

Yes, no documentary proof (of anything) but I could see brand new pistons and valves when I shone a torch down the plugholes. I would expect a lot of smoke if it were burning that amounts of oil, there is none at all, just the oil in the pipes.

[royhall]

I had a similar problem on the 350F losing oil and coming out of two exhausts. After 2 head rebuilds it turned out that the head was cracked. It was impossible to see even with Dye-pen so I took it to an NDT place and they confirmed it was cracked. Something to do with eddie currents, all witchcraft to me. I spent a lot of money on that head before the crack was found. Managed to get a very low mileage one from the states and it's been perfect ever since. Hopefully it's not that on yours but very worth checking out before you start spending money.

[Bryanj]

True, check valve stem to guide cearance whilst in bits the 750F2 suffered badly just like your kawa when they wore

[royhall]

Just another thought, that's a lot of oil in 100 miles check the breathers are not blocked. Long time since I had a 900 but I think I remember it being underneath the air filter. Worth a check.