Cold starting

[Z1B Alan]

Ok folks this is the story.
Purchased the bike fitted with carbs from a Z1R [My bike is a Z1B} the bike always sufferd from a missfire at 4000 so I have purchased a set of correct carbs serviced them and fitted them to the bike. Thanks to GEZ635.
Bike now runs much better with no missfire and pulls strong through the rev's.
My problem is the bike will only start on 2 cylinders from cold and after 20=30 seconds fire up on the remaining cylinders a problem that was not there before, Is this a common thing or can it be cured the carbs have been cleaned, float heights set, balanced with mercury gauges where shoudl I start to look to cure what is only a minor glitch.
Bike is Z1B standard in every aspect apart from new Dyna S.

[bigmac103]

I had the same problem with cold starts too, it was always 2 and 3. After cleaning plugs it would run fine. I checked the voltage at the coils and found it to be around 8 volts. I did the rewire and fitted the relay and it did help. But after a while the coil burned out, nothing to do with the new wiring I just think it was on it's way out anyway. I then fitted the Dyna green coils, points were already Dyna S, the bike starts with no problem now and seems to have a new lease of life!

[Pigford]

Wot he said

Theres been loads of discussion re: latest breed of 'naff' spark plugs now-a-days, which are prone to fouling on older machines

Just need to change them regularly

[Garn 1]

BigMac, you could have nailed Allen's problem. The problem may be a slow breaking down of coil(s). It is very hard to "nail-down". One tends to blame carbs, petrol and or plugs. Even when you you check the voltage at the coils you don't know the voltage on the road. They can break down erratically. I also fitted a DynaS ignition and a "coil direct voltage" relay and had a lot of trouble finding the breakdown of coil. The last thing I wanted to blame was a new Dyna coil and I kept trying other items.

I have recently had a Dyna coil break down in this fashion. The coil had a short between the primary and secondart windings.
BTW, I have sent the defective coil back to Dyna for a warranty claim. Still waiting, however, they have received it !
RegardZ.

[Z1B Alan]

Thanks for the replies I have changed the coils for new ones and swapped these for spares I have so I think I can remove the coils from the equation however would you recomend new plugs As the problem is on two cylinders it dose point to the coil would it be worth a direct earth to the battery just to rule out that

[bigmac103]

After reading the Denso plug thread and discovering that cleaning plugs damages them I would renew the plugs every time.

[floydsz1]

obvious thing to do with the plugs is put no's 1 and 4 into 2 and 3 and 2 and 3 into 1 and 4. then see if the same cylinders dont fire. That should tell you if the plugs are ok or not. Mine used to do it after i had rebuilt the engine but after 1000 mls now its ok. When you start it from cold and they dont fire try pulling the plug cap off the plug slightly and rest it on the plug so as if its not pushed on properly. Do this while the engine is running.This should make the plug fire, after a few seconds when its warmed up abit push it back on.
This is all i did with mine, dont worry you wont get a shock though you can use pliers if you dont trust me,