Odd, very infrequent misfiring issue

[northwind]

Here's a weird one... For about 30 seconds on the way to work and on the way home on friday, I had a loss of power- it felt exactly like it was losing one cylinder, and it also felt and sounded exactly like it was out of fuel, though that doesn't really fit the bill as it takes off again when it stops exactly as usual- so I doubt the float bowls are draining. Definately not a wet plug. I've checked the obvious suspects- kinked fuel line, negative tank pressure, and just on the off chance I've checked the plugs and fuel filters, all look fine. I'm pretty sure it's keeping one cylinder running, and as soon as it stops, it's absolutely fine. No particular conditions to tie the two, and it wasn't carb icing. I doubt it's rust in the tank as the tank is already petsealed. I did have the tank off and the plugs etc out last weekend for a valve clearance check and some other tidying up, but it's done about 200 miles since and only started with this on friday...

Any options I'm missing out on? It might never happen again but it was annoying, so I'm trying to chase it down. Oh, there were no low-power issues, the bike started strongly the next time I started it, and no telltale dancing needles etc. I tried flicking the lights on and off while it was happening in case it was a drain issue but apparently not. I did have a random flat battery last week during a ride but to be honest I'm blaming rider incompetence and excess load for that!

My bike exhibits those symptoms when it is dangerously hot and it stops you from revving to save the engine.

But then yours is a SV and you live in Scotland, so thats probably not your problem.

Originally Posted by northwind

Here's a weird one... I did have a random flat battery last week during a ride but to be honest I'm blaming rider incompetence and excess load for that!

Had same thing a few months back. Stripped and checked EVERYTHING! Even stripped and visually and electrically checked the wiring loom front to back, soldering the crimped multiple connectors along the way. Eventually traced to a naff generator, which fried the reg/rec, which naffed the battery......BTW, all electrical tests I carried out at home came back within normal range. It was only when tested under load at a specialist auto electricians that the faults showed up!!!

An expensive and time consuming month.

Hope this helps.

Mines a pointy but I had a similar problem and it turned out to be a faulty throttle position sensor . I don't know if the curvey has one of these or not . Hope this helps .

[Biker Biggles]

Ignition coil or HT lead breaking down under load or when hot?Faulty plug?

[northwind]

Originally Posted by ASM-Forever

But then yours is a SV and you live in Scotland, so thats probably not your problem.

My SV's been dangerously hot, even in Scotland. Well, OK, I caused a small electrical fire... But you didn't say how it had to get hot

All ideas go into the list of things to check if it keeps happening... Cheers forks.

alarm / immobiliser cutting in.

(if you have one)

It may have a bit of **** in the bottom of/floating around the float bowl that it will now pick up from time to time in the main jet ...

[northwind]

Originally Posted by DoubleD

alarm / immobiliser cutting in.

(if you have one)

I do, but I threw it down the garden last year in triumph after taking it out, and I'm not sure where it landed

I'm tempted to just sling a load of carb cleaner in it and see what happens next... Blue's suggestion seems pretty likely, or something like it.

Loose coil connection?