Z1-B resurrection after 43 years

[ADRIAN H]

Mark Kelleher of MK Classics can sort it out. He is near Reading Berks and highly recommended. You can find him on here as needaz1100r.

+1

[needaz1100r]

Mark Kelleher of MK Classics can sort it out. He is near Reading Berks and highly recommended. You can find him on here as needaz1100r.

No pressure then

[wheelysteve]

I know you like a challenge !

[steve452]

Mark very kindly replied with a PM and I sent him some details of the issues.

However, before going fully down the route of out-sourcing I thought I would just re-check the ignition timing. Lo and behold it was out. Not sure how I managed that but it was about 10 degrees retarded. Anyways I reset statically and it is now spot on. In an attempt to try and cure the misfire on #2 I had previously swapped the plug with #4 plug. No change, misfire stayed on #2 cyl. I checked the HT lead as it entered the Dyna coil and it seemed very loose so I expanded the lead connection a bit (considering the cost of these coils this is a shit way to connect the HT leads) and got a tighter connection. I then checked the voltage at the coil primary input, which was about 9.7 volts. After cleaning the connectors from the switched 12v line and the bullet connectors etc (I had made up my own wires and terminals) and running the power for the pickups through the switched 12v line for the front brake switch I found I now had 10.2v at the coil primary connector. Weirdly, the 12v switched double female connector from the harness (which supplied the original coils) was giving 12.3v via the battery negative post. I checked the resistance of the wire to the coil primaries and they were both around 0.5ohm. My physics ain't that good so maybe the electrickerys amongst us can explain the voltage drop.

Following this I then tried to set the idle mixture using the idle drop (aka lean drop) method. These Yoobtooters who do it must have ears like a bloody bat because I can't detect slight changes in revs whilst turning the Pilot Air screw in and out. The tickover is uneven anyway so it was a waste of time. I got it to sort of tickover at about 1000rpm so tried to sych the carbs. Just adjusting a single carb seemed to send the others into a frenzy so I gave up with them sort of 10Hg ish within each other (ish). And #2 is still misfiring.

I decided to stop when what seemed like smoke started to rise from around the number two plug although that's probably the remains of various cleaning products burning off and the engine by this time was bloody hot.

Next move is to swap the leads on #2 and #3 plugs to see if the misfire moves.

Any further advice most gratefully received.

[steve452]

Finally got out on the Z1-B with the missus. Filthy, dirty, covered in oil, but she's good with the kids (apologies to Tommy Cooper).

Finally went for a run round the block as I'd sort of got it to tickover at 1000ish yesterday. Seemed to run like a pig but to tell the truth I can't tell what it's supposed to run like, not having ridden it since 1977. Also, I'm used to a 400bhp Ninja H2 so may be spoiled as regards acceleration.

Anyway, emboldened by it not blowing up immediately, I took it for a 2 mile run down to the local Esso to fill up with luvverly Esso Supreme (supposedly Evil-nol free in this area). Upon restarting my old friend the oil light refused to go out. Recalling a comment from the forum when this happened before, I turned off the ignition and kicked it over a few times (to release an air lock under the switch?) but to no avail.

I gingerly rode it back home with my left hand hovering over the clutch lever. It didn't seem to be running any differently than before, but when I got it home and took off my skidlid with the engine still running it seemed to be making a lot of rattling noises (possibly need to readjust the camchain tension first off). I also took the opportunity of checking the battery whilst the engine was running and recorded around 14.4v on tickover.

So tomorrow I will be mainly doing oil pressure switch stuff. When I first got an issue with the oil light staying on last year I think I ordered a spare from Z-Power. If so I will replace the one currently installed (which is the 1975 original). Firstly though I'll fire up the bike again and do an oil pressure test just to make sure.

Whilst the bike was warm yesterday I did another compression test (previous one was done cold) and got #1=150psi - #2=140psi - #3=135psi - #4=150psi. Service limit in the manual is 100psi so I'm quite pleased with those figures. I also found that the #2 spark plug (where the misfire was occurring) had a bent HT screw terminal and the white insulator above the nut also looked slightly bent although it could be my eyesight.

[steve452]

Yesterday I re-adjusted the cam chain tension and then started the bike again. No choke and fired up immediately and ran at 1000rpm. Oil light went out immediately it fired up! There is still a rattle from the top of the head which I am assuming may be tappet noise. I may have to re-adjust the gaps again. I set the clearances previously to approx 0.10mm inlet and 0.15 exhaust. Is this correct or should they be closer to 0.15 all round?

Using the take-off just above the breaker plate I did a pressure check. Got about 1.5psi on tickover at 1000rpm, rising to 6psi as I revved it. Are these normal figures?

Discovered that I had not previously ordered an oil pressure switch from Z-Power. The switch I have is the original (bike build date is Jan 1975) and I'm wondering if it is sticking on when the engine has been turned off and then started hot (eg after stopping to refuel). Does anyone know if this is a possibility?

Based on your answers I may just replace it with a new genuine one from Z-Power. They are not cheap however and I'd rather not spend £40 odd quid if there is a more likely alternative to this issue.

As always any help from you guys will be very much appreciated.

Just for your delectation pic shows Granddad and Grandson sitting together

[ADRIAN H]

Service manual bullitin - 1974 Valve clearances should all be between 0.11 - 0.14mm.

[steve452]

Thanks Adrian. I've got this SB but cannot understand a word of the process

It seems to be designed for people who can't subtract

I'll recheck the clearances some time this week.

[Al]

Using the take-off just above the breaker plate I did a pressure check. Got about 1.5psi on tickover at 1000rpm, rising to 6psi as I revved it. Are these normal figures?

As discussed previously that is around about what the manual says if I'm not mistaken. Too low for the J model (@2.8 PSI) but i believe correct or a little low for the early bikes.
They run on volume not PSI as the critical value so even with 6 or even 1.5 PSI it indicates that you have volume flow operating. The actual measured PSI you will see depends on a great many things like; age temperature quality and condition of the oil in its lifespan, condition clearance and wear in the oil pump, condition and quality of filter, condition and wear in the other bearings in the motor which are fed by the pump (example the one behind the clutch) etc etc. Interestingly, the big end roller bearings are fed by centrifugal force and not by pump pressure or flow rate unlike the mains which have a direct feed through oil galleries!!
Does it have the correct oil filter? I believe there may be two different sorts but i think it will be obvious if its the wrong one.
Is there,... a small spring steel shim type washer and a short coil spring below the oil filter? Normal thing when replacing filter is to accidentally discard the thin steel shim type washer as it looks just like part of the filter!!
Did you check the condition and operation of the ball and spring pressure relief valve?
Did you have the oil pump apart?

Going to try to get to Popham Sunday. If i can find it and you i will bring my oil pressure switch and you can try it as an alternative.

AL

[steve452]

Going to try to get to Popham Sunday. If i can find it and you i will bring my oil pressure switch and you can try it as an alternative.

AL

Thanks for that Al, but the oil light seems to behaving normally now. I took a trip up to the Fox and Hounds in Fair Oak on Monday for the monthly VJMC meeting and it went out immediately after start up. It also stayed off until I restarted it upon leaving, then went out again.

A number of people have mentioned that the bike needs to have a few decent runs to settle down and then check everything again (nuts, bolts, clearances etc).

As I posted to Adrian H, I will not be taking the bike to Popham or anywhere else until I can more or less guarantee its reliability.

Really appreciate the offer though and all the advice.

See you Sunday. I'll probably be hanging around the VJMC stand drinking coffee

[Al]

Thanks for that Al, but the oil light seems to behaving normally now.

Serious, well done its a start. I will be under the clock tower at 1.00PM wearing the obligatory check scarf and plus fours, so easy to spot.
If its raining i will be at home.
AL

[steve452]

Unfortunately, never made it to Popham. Weather was not too good and realised I would be walking around a muddy field in the rain for an event I would have to leave at 10:30am, but more importantly I would be mixing with a lot of people who may or may not have C-19. As I was due to travel to my 7-month pregnant, and unvaccinated, daughter's baby shower at lunchtime I thought it was too much of a risk.

Anyhows, I rechecked the carbs off the bike (sixth time!) and some of the float heights were wrong, so I reset them, put me left leg in, shook them all about, drained them and checked again and they were still OK. Gave everything that moves a short spray of WD-40 Silicone and refitted them to the bike.

Today I rechecked the valve clearances which had last been checked cold last October. Obviously during the various start-ups since and the 15 or so miles I've managed on the bike the valves have settled into the seats and the clearances had changed a tadge. Using my new supersonic Starrett feeler gauge I got the following readings (installed shim size in brackets)

EXHAUST: #1 = 0.14>0.15 (2.90)/#2 = very snug 0.15 (2.85)/#3 = 0.14>0.15 (2.70)/#4 = 0.16>0.17

INLET: #1 = 0.12>0.13 (2.60)/ #2 = 0.10>0.11 (2.70)/#3 = 0.09>0.10 (2.80)/#4 = 0.09>0.10 (2.80)

I'm hoping these are near enough OK but would be grateful if anyone here could concur or not.

Now to order a new cam cover gasket from Z-Power and give it all another go after changing the oil and filter.

[zed1015]

Most of those are ok.
the two or three inlets around 0.9 /0.10 are too tight .
0.10mm is minimum so i'd fit the next size thinner shim in those to get back up to around 0.15mm.
The ones on the wide end at 0.16/0.17 are fine.

[steve452]

Many thanks Rob. I'll order 2 x 2.75 and 1 x 2.65 shims from Z-Power.

On another point, I'm running Dyna S coils with the wiredgeorge setup, and using their carbon-cored radio-suppressed HT lead. The caps are NGK and are marked 5Kohm. Am I double-suppressing here and would that weaken the spark at the plug?

[zed1015]

Many thanks Rob. I'll order 2 x 2.75 and 1 x 2.65 shims from Z-Power.
Am I double-suppressing here and would that weaken the spark at the plug?

You must use only one source of resistance otherwise you will reduce spark intensity.
Running two sources of suppression is kinda defeating the object of the wired George bodge too ( sorry ! Wired George "Mod" )