First ride update

[Z1B Alan]

Ok folks a quick recap, Bike is a Z1B standard in all respects running last 2 years no bother until Newtronics ignition died along with a coil. .
Over winter fitted Dyna S after checking correct advance unit with Jeff Suunders two new coils {the genuine one's from Z Power} newplugs {Densos} and finaly a voltage reg/rectifier as this was found to be faulty, This may have contributed to the ignition failure so I am told by the electrical tech's in work.
The problem as reported before is a missfire / unwilling to rev above 4500 rpm. The bike starts and runs up to these revs ok. So for I have changed the plugs {no improvement} stripped and cleaned the carbs [no improvement} stripped the fuel tap and cleaned out the tank {no improvement} and checked the fuel tank breather is clear. Note I never found any debris in the tank /tap/carb's to suggest a problem so am now at my wits end in the search for an answer.
Could my problem be a faulty coil/coils or faulty Dyna S trigger unit any ideas as to what to try next most welcome because I don't have any left.

[PAULJAC47]

Hi If you still have points system fit this first and try, i believe you can leave dyna coils on,get hold of a Gunson tester and observe each cylinder ignition in turn by screwing tester into plug hole,have you set up timing with a strobe you say you have cleaned carbs but i had an indentical fault to this and it was a partially blocked main jet looked ok to the naked eye but when measured the internal diameter was less on one than other three,get all jets ultrasonically cleaned...Cheers Paul J..

[ROZZER]

My money is on the Dyna S our kid. Will check timing with strobe on Thursday when I come down, if you remember we had to adjust pick ups to extreme of adjustment to get correct timing right. Can you get the coils checked in work beforehand? Gonna bring my old advance /retard unit and try that, see if any different, your A/R unit looked different to any on Z1 enterprises pages so it may be down to the rotor, sure Jeff will send the alternative to try. Sounds like timing is way too retarded in not wanting to rev.
Wonder if anyone has heard of faulty Dyna S pick ups, normally ultra reliable but you never know.

[Pigford]

Dyna have had some problems with quality in recent years... the stuff is now made in the Orient

My Dyna 2000 packed in... the main "blue box" threw a wobbly..... Sent it back to USA & they replaced it after checking it out

Valve clearances OK

[Z1B Alan]

This is where we are now Dyna S found to be slightly retarded so re-timed spot on also swapped the coils. The bike now revs better however it still seems a little reluctant to rev cleanly to the red line. Attention now seems to turn to the carbs with details as follows mains 115 pilots 15. When I bought the bike I was told the carbs were offf a z1 the exact model I am not sure as the jetting does not tie in with any particular carb listed in the Clymer manual. So from the photos could anyone tell which carbs they are and comment on the jetting in relation to my problem as listed in previous threads.I must say the bike dose not seem to be running rich. Starting to get a little desperate now Just to add we have also checked the valve clearences and all are O.K the bike ran fine the last two years could not draining the carbs over winter really have caused these problems?. Especially after so much effort went into cleaning them the other day.

[Pigford]

Hmmm, mains 117.5 or 120..... pilots 17.5

If not drained over winter....... could well be blocked...... Float heights.... fuel tap...... blockages.....

[Z1B Alan]

Fuel tap is Pingle and flowing faster than money from my bank account, float heights were set by our kid {John Roscoe} last year. But plaese keep the ideas coming.

[Pigford]

Mice in air filter

NGK plugs

[northman]

Now this might sound silly but...I had a very similar problem on my 1000a1 last year. Did all the usual stuff like you did, electrics and fuel,new this, that and the other. All good, and me still pulling my hair out. The bike had a really bad misfire at a certain point in the rev range. It turned out to have a hairline break in the positive feed from the battery. The metal was held together by the insulation, and externally nothing could be seen. And the bike ran fine until reaching about 4-5000 rpm. I reckon that when a certain frequency of vibration was reached the crack in the wire opened, leading to intermittent sparks. Made a new lead, and problem solved (thank f#ck)!

[ROZZER]

Just to re cap what we have done to the bike to date, Dyna S fitted and timing checked by strobe- spot on. Coils changed, plugs changed (Denso's), fuel tank drained, fuel tap checked for shite/flow, carbs cleaned out but no dirt evident and all airways run through using cellulose thinners, valve clearances checked all OK, carb rubbers OK and tight, new air filter fitted, new fuel filter fitted, fresh fuel used.
Bike runs great up to 6k then reluctant to rev , it will rev higher if you roll throttle on very slow, try opening it quick and it just bogs as if starved of fuel (or overfuellling?). Dunno what to do next, it appears carbs are off a Z1R but I didn't have time to take em off to measure (I live 160 miles away from our kid). Jetting is 15 pilots and 115 mains, mains seem a bit large for std motor on a 900 but plugs don't appear to show running rich, if anything they were sooty around the outer thread section but insulator was very pale brown/white which suggests running weak?
I reckon Alan should run the bike as is for a couple of hundred miles and see if running fuel through improves the situation, I now think that its a fuel issue rather than ignition cos if Dyna was iffy it wouldn't run good at any revs, being just a magnetic trigger it shouldn't run any different over 6k than at tickover, unless anyone knows different?
If that don't work I will have another go at the carbs when I come down for the Donington show.

[PAULJAC47]

This sounds like you are not getting enough fuel when the main jet cuts in my B is running 117.5 mains!! try raising rhe needle a notch to see if matters improve and check all holes are clear in emulsifier tubes sometimes jets look clear to the naked eye but are blocked partially internally.Cheers Paul J..

[Pigford]

Yep, sounds weak.........

Bung in some 120's to see if it improves......

As a rough check (not always conclusive) go along at 6000rpm --- put choke ON---- then whack throttle open.... see what happens.

If it dies as the slide is opend further, that probably means too much air to fuel