no start no spark

[user 16790]

I've recently had carb troubles on my 1991 that got sorted out at my local shop, it took quite a while to get them balanced correctly but they were done great (I watched),
when I rode the bike home I noticed a noise that I'd not heard before, when shutting off the throttle at around 2500 - 3000 rpm there was a noise like a tyre rubbing on a mudguard (very audible), lightly touch the throttle again and the noise went away, pull the clutch in and the noise halved but was not gone, no noise at idle at any revs, just at the stated rpm in all gears, other than the noise the bike rode brilliantly,
I checked over a few things that might cause the noise like items not quite aligned after the carb work but all was good, the following day I rode the bike and still all good apart from the 'coasting' noise, I put the bike back in the garage for the night,
the following day I go to start it from cold and it will not start, it turns over really fast and you can smell it getting fuel, I check the sparkplug and it is wet with fuel, check for spark and there is none, try another plug and no spark, no sparks at all,
any idea why the sparks would stop all together after it worked ok the day before, I mentioned about the noise above just in case it is related, my local shop will come and collect it again but it would be nice if there was a possible culprit that I could tell them about,
my local bike shop owner has had several Vmax's and currently still has one,
thank you for any help as I am absolutely useless with electrics

edit. I just remembered that when the bike was first being looked at and running seemingly on only two cylinders, the spark plugs were checked and with the caps removed and the ht lead was put on the cylinder head all sparks were more yellow than blue which was thought strange at the time, maybe that was the beginnings of failure ?

 

[one2dmax]

You can check the pickup coil? Unplug the connector under the seat and measure the ohms on the wiring going down and to the pickup coil on the left.

 

[user 16790]

thank you, I'll give this information to bike shop mechanic, I do not have any measuring equipment and wouldn't know how to use it if I did, I 'll see if I can watch how they do it

 

[Fire-medic]

Here you go. A less-than $10 Harbor Freight electrical meter should work.

The last page is for use on the 1985-'89 pick-up coil, with 5 wires. The 1990-2007 pick-up coil only has two wires, so it's much-easier to read.

The pick-up coil reading is 110 ohms plus or minus 15%, so the minimum would be ~94 ohms to maximum 127 ohms. Just use the probes one on each of the two leads in the single plug Sean shows. There are aftermarket replacements for the OEM pick-up coil, which is pricey.

Pickup coil V-Max VMAX VMX1200 Yamaha (regulatorrectifier.com) $130

 

[user 16790]

although I have no spark at all now, would a failing pick up assembly be likely to cause the bike to have yellow sparks at each cylinder or could that be something else, if so what else could cause that, or is a yellow'ish spark normal for a Vmax

 

[MaxMidnight]

although I have no spark at all now, would a failing pick up assembly be likely to cause the bike to have yellow sparks at each cylinder or could that be something else, if so what else could cause that, or is a yellow'ish spark normal for a Vmax

This is speculation but I would say not; the pick-up coil provides the signal to the ignition control unit (ICU) to say when to fire the plugs. The ICU and plugs have their own power supply and therefore apart from the fire signal do not rely on any power from the p/u.

A weak spark would be more indicative of old or failing components or high resistance in the circuit.

Quoting from Haynes any of the following could be the culprit:

• Low battery voltage
• Spark plugs defective, dirty or worn out
• Plug caps or HT leads defective, Donald ducked or dirty, in particular where the HT leads fit into the coils and screw into the caps.
• Plug caps not making good contact
• ICU defective
• HT coils defective
• Engine cut off or side stand switch
• Wiring issues between:
  • Ignition switch and kill switch
  • ICU and kill switch
  • ICU and coils
  • Coils and plugs
• Dirty or poor connections between ignition system components
• Immobiliser (if fitted) not disarmed (been there! )

 

[user 16790]

ok thank you, lots of things then, maybe I'll just try to sell it as a project
I just can't do electrics

 

[02GF74]

You're not having much luck since you decided to sell (the bike is telling you it does not want to go!!)

IIRC the last thing done were the carbs being cleaned at your local garage, for that, unless I'm wrong, no electrical connections need to be disconnected/reconnected. It is possible they disconnected the battery as a precaution so I would suggest checking the battery terminals are clean and tight.

To get a weak spark at all 4 plugs should rule out ignition leads or coils as it is unlikely for them to have all failed at the same time.

Also check that battery is fully charged and clean spark plugs or fit replacements - cheap enough.

 

[user 16790]

battery is good, it turns over really fast, no connections were undone,
the guy who owns the bike shop has his own Vmax and also lets me do stuff on my bike there as I've done them a lot of favours over the years including making a hole in the floor for the mot brake testing equipment, he will help me out and I try to learn but I just have a mental block when it comes to electrics, I've ruined 2 multi meters by connecting them wrong in the past,
I was hoping to get a narrowed down possible problem but it seems there are lots of things that are possible, while the shop doesn't charge me a lot for the time (sometimes nothing) I can't afford to buy a lot of bits as a recent £4000 vet bill has wiped us out, I now need to sell the bike to pay it off

 

[user 16790]

I spoke to my shop and they let me borrow their multimeter to take home and test my pick up coil, but first they showed me how to use it and left it set on the correct setting/position, they also gave me a used coil from another bike to take home so I could check that I was using the multimeter as I was shown so that I'd know that I was using it correctly what ever the reading was on my bike,
so as in the photo above given by Sean I tested the wires inside that connection plug, I tried it several times and the reading on the multimeter never changed from what it showed with out touching anything,
my shop tells me I have an open circuit but before buying a replacement coil I should check the length of wiring just to make sure one hasn't broken, when and if I take it off they will test it again for me just to be sure, they are a great shop
do I have to drain the oil out to be able to remove the generator cover ?
just need to wait for a warmer day that allows my joints to move freely before attempting the job

just for interest, this is our dog after his operation, unless circumstances change I will have to sell the bike to pay off the bill, I will keep hoping

 

[MaxMidnight]

Do I have to drain the oil out to be able to remove the generator cover ?

No, but you will loose a little so a drip tray underneath will be prudent.

If you haven't taken the generator cover off before I've attached the starter clutch 'How to', the first part covers removing the generator casing.

 

[user 16790]

thank you

 

[user 16790]

hello, just an update on my no spark issue, finally got the bike to the shop where they replaced the pick up coil and the bike started instantly, now the shop is going to sell it for me, thank you to all for all your help and advice

 

[Fire-medic]

In 29 years of multiple VMaxes I've replaced two pickup coils. Two different bikes. It happens, and you're no-go until it's replaced. Glad you got it done. Good luck with the pet.

 

[VMAXXIMUM]

I too, have a no spark, no start problem. I shut it down Sat. night when I parked it and Sunday morning no spark/no start. I have verified the pick up coil is good. The Ignitech has power in and power out. The cops are energized. The coil's are obviously not getting grounded. Could it be anything else besides the Ignitech?

 

[02GF74]

How are you checking the cops are energised?

The cops have one wire that is power and another that I'd switched to ground.

If you put a voltmeter on the switched wire, it should be at around 12v. If the engine is turning, the switching to ground will result in a lower average voltage depending on the response time of your voltmeter. Ideally you want a' scope on it to see it switching.

Alternatively you should see a led flash when wired to power and other end to switched wire (with drop resistor).

Ensure battery is fully charged and not starting to fail, from what I read, vmax starting is sensitive to battery condition.

 

[VMAXXIMUM]

Problem discovered. I hooked my old ecu up and presto it fired right up. Bad ignitech. Time to email Sean