Z1-B resurrection after 43 years

[Al]

The blurb states that you fit it by removing the oil gallery bolt on the side of the engine. I'm guessing this is the one just to the upper right of the clutch cover (92066-021).

Thats it, fits after you remove the plug at the base of the barrels, RHS, above clutch and timing covers.
Somewhere i have the switch that i removed from mine. It was working when i took it out. Unfortunately that was 12 years ago and i cant vouch for it now or i would happily send it to you as another form of test.
AL

[steve452]

Update #645 from the Sunnybike Care Home.

Finally fired it up again after resolving the carb issue (pissing out fuel on #2 overflow). Could not work out what the hell was going on (had swapped out just about everything in the carb including the float bowl!) and this issue had haunted me since last year. Finally swapped out the float unit itself from my spare set and worked first time! No overflow and fuel level was spot on. Go figure.

Anyhows, it fired up on the choke and spluttered and coughed but eventually ran. Took the choke off and adjusted the idle down to about 1300-1400 with the throttle stop screw (but see below) and it sort of ticked over.

#1 cylinder was spluttering like hell and judging by the temperature of the pipe and exhaust (cold) was not firing. It was kicking out shitloads of smoke but there again I did smother the bores with rebuild lube. It was getting late (17:30 is 30min warning in the care home for dinner ) so I've left the non-firing #1 cyl issue for tomorrow.

One oddity I noted which I'd be grateful for advice on is regarding the static position of the Throttle Stop Screw. Manual says there should be a 10mm gap between the screw head and bracket (see pic) but if I set it to this on mine there is a gap of about 3 or 4mil between the end of the screw and the bracket. Have I assembled something wrongly?

[steve452]

Finally got out to the garage to set up the carbs with my super-duper Carbtune Pro and my 50 year-old Gunsons Colortune and two cooling fans. Managed to get it starting on the choke and eventually ticking over at about 1500 revs although still coughing and spluttering, particularly on #1. However, as the engine warmed up it became pretty obvious that no matter what I did the revs kept rising, and eventually it was ticking over at about 5000! At this point the pilot air screws were only 1/2 turn out having started at the recommended 1 1/4 turns out. The throttle stop screw was not touching the throttle bar, and the closed-throttle stopper screw was not fouling the throttle quadrant. There was still a small amount of play in the twistgrip and I'd previously checked that all the relevant screws and clamps were tight. And I also checked to make sure I'd installled the air cleaner (which is genuine). I'd already had the vacuum gauges connected and #1, #2 were miles too high and #4 was too low. #3 was running about 22" Hg which is in spec. Every time I adjusted the vacuum the revs shot up, and I eventually got them all within about 10" Hg when I gave up as the revs were going mad and waking the neighbours. In a flash of inspiration I turned the choke on and the revs dropped immediately. I could get the idle down to about 2500 by using the choke but putting it full on would stall the bike. Obviously it's running massively weak but I have no clue as to why.

Any help would be much appreciated as I frankly haven't a clue what's going on.

I'm running Dyna S coils and breakers, OEM cams etc and all the static ignition and valve timing and shims have been checked and should be OK.

I did a cold compression check and got (from #1 to #4 in order) 110, 122, 115, 137. Engine has done around 22,000miles.

Help!!!

[wheelysteve]

By throttle stop screw I assume you mean the screw to adjust the tickover revs. If this is not touching the throttle shaft and you still have revs, then 1 or more of the slides must be bottomed out and forcing the throttle shaft to open all the throttles. I would suggest removing the carbs and setting the synchronising on the bench using a .7mm or thereabouts piece of wire under each slide until they are all exactly at the right height ( after having set the throttle screw approx 10mm out).

[steve452]

Could the possibility of one of the slides being bottomed out be checked in situ by removing the carb top caps and manually lifting each slide to see if the throttle shaft then moves?

[wheelysteve]

Trouble is , once you start adjusting the slide heights "blind", you can't be sure where they are . At least on the bench you can set them as a datum to work from. If you are struggling to balance the carbs on the bike with vac gauges, I would check to see if one or more of the carb mounts are leaking air in at the head. I had a similar issue to you on my Z1r and after completely buggering the the synchronising , I had to remove the carbs, set them up on the bench and refit. I then spayed brake cleaner at the joint where the rubbers meet the head and found one drawing in air. Removed the carbs again and re-sealed the rubber to the head, refitted carbs and then I was able to synchronise them with the gauges.

Hope this helps

[steve452]

Many thanks for the advice. I did set up the carbs on the bench originally using a .6mm wire which was the closest I could get to the recommended spec, although I couldn't find the notch that is described in the SM.

I would hope the inlet rubbers aren't leaking as they are brand new genuine parts from Z-Power.

Looks like I'll be bench setting them yet again (5th time!).

[Philippe]

Hi Steve

practice makes perfect !
Try to attach a weight on the wire you're using.
The notch in the slide is very tiny and sits on the engine side of the slide, at the bottom.
When performing a static synchronisation, loosen all the adjuster screws of the 4 slides, put the idle screw as described and go for it.
When the wire is in the notch of the slide, hang the carb you're working on, over the edge of the workbench and slowly adjust the slide by turning the adjuster screw in.
At the moment the gap is the thickness of the wire, the wire will fall out of the carb and then you can gently fasten the nut without moving the adjuster screw.
Do the same procedure with the other carbs.
I hope you succeed. Good luck!
GrtZ
Philippe

[steve452]

Cheers Philippe. I will do this.

Mind you on first reading I thought you said hang the CARB off the bench on the wire and adjust until it falls off Had visions of the carb bouncing across the garage floor!

Many thanks for the advice.

[Philippe]

Hi Steve

I know, my English isn't that good. .. but giving you the advice of dropping your carbs on the floor...I would feel deeply ashamed if I had written that. Fortunately I didn't
All the best with synchronising your carbs !
GrtZ
Philippe

[steve452]

Well I couldn't find a decent enough length of wire so I used one of those ties that you twist onto freezer bags the measured about .67mm. Couldn't attach a weight as it was too short so pulled it with one hand whilst turning the adjuster screw with the other. Those notches are practically invisible but I reckon I've got about as near as I'm going to get with my 69 year-old eyesight (see pics of two of the throats after adjustment). I then hit another problem with the "closed throttle stopper" screw (see pic and SM graphic). The SM says turn the screw until you get a gap between 1.5 to 2.0mm. In fact this gap is for the earlier carbs. Mine should be 2 to 3mm as noted in the SM Supplement. The widest gap I could get was a tight .35mm. Still it is what it is and I've now got to the stage where if this doesn't work when I reinstall them tomorrow then there's going to be some scientific experimentation regarding the bounceability of 28mm carbs off a steel garage door. These carbs are doing my head in.

[wheelysteve]

The shaft may be twisted. You can check it, but of course this means taking them to bits again

[steve452]

The shaft may be twisted. You can check it, but of course this means taking them to bits again

Got the shaft out without pulling too much apart. Have checked it against a straight edge and rolled on flat glass. It's definitely not bent or twisted within reasonable limits (certainly not enough to give the symptoms I had on tickover). One odd thing I noticed though was that when adjusting the closed throttle-stopper screw it requires you to adjust it up as the lowest throttle slide has just reached the top of the throat. Looking into the throats when doing this both #3 and #4 carbs are just at the top of the throat but #1 and #2 are about 2 to 3mm below the top so clearly visible by about the same amount. I've rechecked all the adjustable bits but cannot find any issues. Is it possible that the throttle slides are different lengths or are seated differently? All the carbs components bar the float bowls of #1 and #2 are from my original set (#1 and #2 float bowls are from an original 217 set which I bought for spares).

[steve452]

Finally decided to strip and partly rebuild the carbs...again! This time have managed to setup the initial slide height using .7mm RC model aerials. Managed to get the carbs sync'd-ish (they're quite close at about 3000 revs). Have a misfire on 4 and it's ticking over very unevenly at 1000 revs but better at about 1400.

Have decided to cut my losses and hand it over to an expert to do the final set-up. Can anyone recommend someone who will check the timing, charging circuit etc. and then set up the carbs properly so I can get this bloody bike on the road and running properly, without costing a complete arm and leg.

Preferably someone not a million miles from Southampton as I may have to hire a van or trailer.

[wheelysteve]

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.