Engine stuttering in all gears

After running without a problem for at least a couple of weeks my bike has decided that enough was enough and has thrown it's toys out of the pram again so I'm back begging for more advice!

In the last couple of days my 2000 SV650S has been stuttering quite badly between about 3k and 6k rpm, it happens in all gears and while cruising or accelerating. It just feels like a momentary loss of power followed by it immediately picking back up again, but it is doing this pretty constantly over the rev range.

Has anybody got any suggestions as to what I should be checking to start with? I was planning on changing the oil on Monday, I'm not sure it needs doing and I'm certain that it won't make a difference but I was planning on doing it anyway, but assuming that an oil change doesn't help, what should I be looking at/for.

Thanks.

[Geodude]

Im not that much use compared to the mechs on here but just a suggestion whats the condition of your chain and sprockets and hows your plugs? Clever people will be along soon with a better idea im sure.

[MrMessy]

Have you done any work on the bike before this started? Check plug condition, plug leads, fueling any breather pipes blocked. Choke operating O/K. Any loose wiring connections to coils etc?

Is your chain adjusted?

Chain was adjusted about 3 weeks ago, although I will check it tomorrow.
Sprockets are a bit worn but nothing major at all, due to be replaced in about 2000 miles.
Spark plugs haven't been checked for about 6 months so I'll give them a check.
General wiring/pipes haven't been looked at yet but I'll give them a going over although all was fine a couple of weeks ago.

Will update this thread once I have done a bit more investigation.

Anybody who read my last post that I just deleted, ignore it, I'm an idiot!

Took the bike out for a proper test ride after adjusting the chain tension and properly lubing it and the problem is still there.

It sounds like the engine is bogging down, the bike feels like it just stops accelerating momentarily, and I hear a low pop from the exhaust. It also happens far more frequently when the engine is labouring, so when accelerating from low revs it is worst but it is much smoother if I'm over about 6.5k rpm, I can still feel it stuttering but it feels less severe.

Am I right in thinking it sounds like it is misfiring as to me that would explain why it is smoother at higher revs?

I will get the spark plugs out tomorrow and check them as in my mind they seem like the most obvious cause of this problem, but I may well be wrong.

[maviczap]

Originally Posted by MrMessy

Have you done any work on the bike before this started? Check plug condition, plug leads, fueling any breather pipes blocked. Choke operating O/K. Any loose wiring connections to coils etc?

Like he said, this is a fuel or ignition problem, its not something that can easily be diagnosed over a few posts.

Could be something as simple as a spark plug, but taking it to a garage might sot things out quickly, as it sounds like you're not experienced in fault finding?

Long time since the last update, but I hadn't had a chance to do anything to the bike.

Having had a proper listen it is misfiring all the time, so it's not just when the engine is under load.

I'm changing the spark plugs this afternoon as when I took them out they were pretty badly corroded, however the company I bought the replacements from sent CR9E plugs instead of CR8E.

So, simple question, is there any real disadvantage to running with CR9E plus?

Thanks.

[TamSV]

8's a hotter plug IIRC. 9's should be alright. I've used both in the SV.

If they start fouling up switch back to 8's but I'd be surprised if you had a problem.

Thanks.

Well having given it a bit of a test ride on my way down & back from work it all seems to be peachy now, misfire seems to be gone and all is good.