bike will simply not fire up!!!!

[PAULJAC47]

Hi 70 psi is a bit low over 100 more like it up to 150 hot,put a tea spoon of oil down plug hole and re-test if it raises a lot suspect worn bore/rings.Start logically check fuel flow to carbs,take out drains and make sure all carbs have fuel.and all same height of fuel use manometer method,next make sure battery is fully charged and able to spin engine quickly, ,check static timing and strobe timing fit Denso plugs NGK are rubbish,if cam cover off check valve timing,check secondary resistance on coils with multimeter should be same on 1 and 4 as 2 and 3,make sure if you have messed with wiring left hand set of points fire 1 and 4 coil,Zeds will run with a whiff of fuel and a bit of juice this is bound to be something daft,Cheers Pauljac...

[jakeymara]

Had to put my mind at rest about compression. Just taken the bike off the lift and gave it a good kicking over, all pots are 100 to 120 psi on a stone cold engine, so that should rule that out!

I bought the bike with the Dyna S already on it, so I have no installation manual etc. What should be a typical coil resistance, approx 5 ohms...ish?

I understand Dyna make a number of coils, but I am not sure what model of coil these are. All I can say is they are green stating "Dyna Coil" on them.

Battery is above 12 volts so is good. Will take your advice and try some Denso plugs if you say NGK are rubbish.

[Pigford]

Green = 3 ohm
Grey = 2.2 ohm, both OK for the Dyna S & a Zed

[jakeymara]

Blimey Pigford what don't you know!! Just shows I know diddly squat about these Zs, but learning all the time.

Green is 3 ohms, ok I will go with that.

[Rich]

"This just tells you if fuel is at the correct level" which is exactly what you want to know. Float height doesn't tell you the condition of the needle or seat.

[compo z1r]

Blimey Pigford what don't you know!! Just shows I know diddly squat about these Zs, but learning all the time.

Green is 3 ohms, ok I will go with that.

jakey have you got it firing yet

[jakeymara]

I have not had much time to look at her since Sunday, I am working through it slowly and methodically.

As recommended I am going to try new Densos on her, which I ordered yesterday. I spent what spare time I had last night checking out the ignition/ Dyna S system. Which seems OK, voltage test seems fine so modules are switching on and off as the magnet rotates, but the multimeter packed in on the ohm test (primary and secondary circuits). Hope to jump through the ignition hoop tonight by borrowing my dad's meter, as an ex electrician his meter is better than mine.

All being well, it will be down to messing with the carbs it cannot be anything else after that.....joyous Jap carbs, not one of my fortes I have to say.

[stephen lavery]

having the same problem,doing me head in. fitted denso plugs charged battery again,also jumped her with car battery getting a good spark. cleaned carbs fresh fuel. have great compression. squirted fuel down plug holes it tried to fire up when i done this. but wasnt to be. I KNOW HOW YOU FELL AT MOMENT.

[jakeymara]

Steve I can symathise. but at least my Benelli Tornado is back from the dealer on Thursday so I cannot wait.

Checked out the Dyna S modules, they switch on by measuring the volt drop across the coils with the magnet away and facing each Dyna S module.

Primary reisitance is Ok at 3 Ohms, but secondary resistance baffles me. Dyna say about 13.5 to 14.5k Ohms for secondary resistance. I have 21.6k Ohms on one coil and 76k Ohms!!!! on the other. All the plugs still spark though, but does it mean the coils are stuffed?

[stephen lavery]

my bike had been striped over a year ago. compression was bad, cyl,s were honed new s/s valves, guides, cam chain and battery.i fitted a new boyer ign about 4 months before strip down. got this advice from classic motorcycle mechanics.( i know now dyna is the only way) checked carbs again. feel i should stay away from the big zed for a while or i might do something very stupid!

[knut]

jakeymara , it sounds like a fuel problem,were the plugs dry or wet when you checked them ?

[jakeymara]

Knut, the plugs had a splattering of fuel on them when I last had the carbs on and turned her over.

I would subjectively gauge not enough to get it the engine going. I have always suspected fuelling. But I have acted on other advice given on this thread, in case it was something else. I just want to avoid messing with the carbs if at all possible. But if the ignition system, in particular the secondary resistance values as given earlier are deemed fine, then it has to be fuelling, there is nothing else it can be.

Steve just walk away from it and come back to it later. I would hate to hear of you doing any damage to the bike. If you have a Z, it is best to have other bikes to use in the interim.

[PAULJAC47]

Hi if you think there is not enough fuel going into engine,one trick i have used is to blow gently down each carb vent pipe(fuel tap on),this will force fuel into the engine,give it a go I have used this on bikes that are hard to start with some success in past,Cheers Pauljac...

[Ginger Bear]

I ended up completely filling the engine and exhausts with petrol trying to start the car. I am mentally scarred by it.

Feck, Im not surprized!
My Haynes manual suggests 1/8th of an inch below the bottom edge of the main carb body.

[BShaw]

I feel for you. A few years ago I had the same problem after leaving fuel in the carbs over winter, I buggered around for a couple of weeks then because of work decided to give it to a mate to sort for me, loaded Zed in the van and drove it the couple of miles to his place, unloaded bike had a chat jumped in the van and went. I got about half a mile and he rings me with the sound of my bike revving in the background and him calling me a tosser. So put yours in a van and drive it round the block. SORTED.
Every year now I flush fresh fuel through before trying to start and jump it from a car battery.
Baza