Another Stutterer

[red98]

I have a similar issue to you the bike pulls fine then hits a bad spot like the fuel of spark is been turned off from around 6 to 10,000 rpm.
light throttle no issues at all and it pulls Up to 6000 fine, from cold it's much better.
And I have a ticking noise similar to a spark arking I'll be taking the leads apart shortly !!!.
Glad you sorted it

Sent from my Nexus 7 using Tapatalk 4 Beta

easiest way of seeing if its arking......wait until it gets dark,easy to spot then 

[littlejohno]

I'll be checking later annoying the neighbours lol

[unfazed]

[quote author=unfazed link=topic=8360.msg82628#msg82628 date=1371679583]
Check the rubber plugs on the vacuum take of points as they can crack and go unnoticed.
Check the wires to the pickup where it enters the alternator cover.
It is good idea is to take all connectors apart and spray with WD40 while checking for chaffed wiring.
A common place for corrosion is on the fuel pump connector and the pickup up connector.

Hi Unfazed. I checked the Vacuum plugs when I did the carb balance. They look ok. Visually checked the loom from the Pick Up Coil we're it comes out of the LH Engine Cover. Also had a look at the connectors under the LH side cover. Nothing obvious there.
The Haynes manual states if you want to replace the pick up coil as its part of the Alternator it has to be replaced as well. Need to be sure it's the problem as that will not be cheap to buy.
[/quote]
Unfortunately it is the same across many Yamahas I had that problem with aserow some years ago and had to replace the alternator at a cost of £275 becaus of a low insulation on the pick up coil circuit.
Was going to recommend checking the plug caps as your source of the problem but I see Darrsi got there before me. The plug caps can arc to the head and is a very distinctive sound as you noticed. The biggest issue with the caps is that it can become very intermittant and often happens for a short while after washing the bike and disappears until the bike gets dirty again due to the build up of dirt around the caps.
I changed the caps on the 400 some time ago with NGK straight ones for this reason, but the symptons were slightly different in that it slowed as if the brakes were binding.
Glad to see you got to the bottom of it.

[Buzz]

Remember to cut 5mm or so off the end of the HT lead before fitting the new ones, gives a nice new shiny contact for the screw in the cap. 


I use the exact same caps as darssi so they're fine...much better than paying £50 a quid a pop like you would for the official Yamaha ones!

[littlejohno]

Leads cut still no better

[CRH]

.....sell it to red98 he might be able to make a good one owt the two!! :rolleyes .......

[red98]

.....sell it to red98 he might be able to make a good one owt the two!! :rolleyes .......

you jest CRH.....i do look on ebay for "accident damaged fazers"  fairly often.....could swap parts,solve stutter,then break the spares bike on here  [size=78%] [/size]

[littlejohno]

I'm determined to fix it ive never been beaten yet >