A couple of days ago the bike began to idle a little strangely. Sometimes low, sometimes high, but usually low and cutting out occasionally.

Then she just started to run real bad at low revs. Sputtering and backfiring until I opened the throttle right up. A quick run up the highway would fix this though, then she would run OK.
Yesterday, she was hesitating and backfiring all day. Even when she had warmed up...

Today she wouldn't even start.

There's plenty of battery power to turn the engine over.
The plugs are sparking. I did take them out for a look, and they are quite dark and wet.

I thought I might have gotten some bad fuel. I filled up at a servo I don't usually go to.
I drained the tank and inspected the fuel - nice purple ULP colour, no water.

I've re-tensioned the timing belts too.


Any ideas guys?

My limited mechanical knowledge means I'm not much help...... but I can be sympathetic. 

Someone will be along shortly to offer an  opinion.

Is yours a FI model?

Yep, 2000Sie.

And to make things worse, the car is off the road too. I'm half way through an engine conversion.
I need the bike to get more parts for the car and I'm getting dangerously low on beer 

Just a query, what grade of unleaded are you using...?    I had a similar problem early on, premium unleaded (98) was the cause, by switching to 91, or 95 max cleared it out eventually. Am sure someone here with much more knowledge than me will help you soon. Oh yes, and definately steer awya from ethanol blends, they will definately play havoc with it.

brian

Did you try a new set of plugs?  If your current ones are dark, they won't be providing a very good spark, which will only cause them to foul more.

Quote from: suzyj on September 22, 2010, 11:40:33 AM
Did you try a new set of plugs?  If your current ones are dark, they won't be providing a very good spark, which will only cause them to foul more.

Ditto!! Like she said! 

NGK Iridiums are exy but perform better for longer!

Have you checked your air filter?  If the plugs are dark and wet to me it suggests that there is a rich mixture setting, which on older bikes would be like riding with the manual choke on!  I would check around the intakes and the air filter to make sure nothing is fouling.  Throttle cables attached ok? Nothing loose? Next get some new plugs like Suzyj recommended.  After those basics I think you start heading in to the murky world of coils, injectors etc etc.

Quote from: dragonworld on September 22, 2010, 01:26:02 PM

dragonworld are sexy and perform better for longer!

Quote from: Brian W on September 22, 2010, 11:27:28 AM
Just a query, what grade of unleaded are you using...?    I had a similar problem early on, premium unleaded (98) was the cause, by switching to 91, or 95 max cleared it out eventually. Am sure someone here with much more knowledge than me will help you soon. Oh yes, and definately steer awya from ethanol blends, they will definately play havoc with it.

brian

Sorry to thread jack..... Brian, i am useing 98 octane in my S4R and since the mid pipe install it has been backfiring as you know. I tried my first tank of 95 this week and am 1/4 of the way through it with similar symptoms.

Would you suggest giving 91 a go?


p.s. Thylacine is an interesting name for your baby...... I dont mind Tassie Tiger

Quote from: cakeman on September 22, 2010, 02:33:42 PM
Sorry to thread jack..... Brian, i am useing 98 octane in my S4R and since the mid pipe install it has been backfiring as you know. I tried my first tank of 95 this week and am 1/4 of the way through it with similar symptoms.

Would you suggest giving 91 a go?


p.s. Thylacine is an interesting name for your baby...... I dont mind Tassie Tiger

guys to further thread jack again can you be more specific with the brand of fuel you are using?  I use premium unleaded in my S2R 1000, and find that the fuel from BP service stations are the best IMHO.  Then from there it goes down.  Whilst I dont suffer the backfiring I do notice performance and mileage issues when using other fuels. 

Quote from: Mr.S2R on September 22, 2010, 02:53:15 PM
guys to further thread jack again can you be more specific with the brand of fuel you are using?  I use premium unleaded in my S2R 1000, and find that the fuel from BP service stations are the best IMHO.  Then from there it goes down.  Whilst I dont suffer the backfiring I do notice performance and mileage issues when using other fuels. 

Generally what ever i can get, its usually Shell or Caltex

OK, so I pulled the plugs again this morning and cleaned them up as best I could.

On starting it sounded like she fired twice, then backfired, then nothing.

Quote from: cakeman on September 22, 2010, 03:03:22 PM
Generally what ever i can get, its usually Shell or Caltex

ah ok - I am not impressed with the quality of the fuel.  I think you will find others will agree what you put in to your baby counts also!

Quote from: Yellow Meanie on September 22, 2010, 03:08:03 PM
OK, so I pulled the plugs again this morning and cleaned them up as best I could.

On starting it sounded like she fired twice, then backfired, then nothing.

mate sorry to sound like a broken record but how old are the plugs? Cleaning may seem the right thing to do but plugs do eventually break down.  If you get new plugs you are eliminating one part of the problem.  Also check the gap - make sure that is correct when you install new plugs.  Check the leads also to make sure they are not 'leaking' i.e. you will hear an electric snap if the leads have a crack in them and are earthing out on the motor or frame.

Success 

After another go she fired! Real rough though, with LOTS of backfiring - the whole suburb would have heard it...
Above about 4000rpm she was ok.

I checked the timing belts again, now she's running ok above 3000rpm. Still backfiring down low and will not idle.
The fuel is very low, so I'll go and fill up at my local servo.
And go and get some new plugs too 

What fuel would you suggest mrs2r?

She's now running better than ever!

I checked the timing - again.
The air filter is clean.
The air box lid has temporary been replaced by a couple of zip-ties. In an attempt to lean-up the mixture slightly...

There is a Shell servo just around the corner from my house, so I filled up with 95ron PULP.
After filling up, she spluttered a bit going up the hill towards the 100 zone.
The 100 zone allowed me to do a bit of WOT - heavy breaking - WOT, then some sustained high rev cruising.
After a couple of kays I was back to a 60 zone, and she was running like normal.

I went to 3 different bike shops in town as well as Ripco. None have Iridiums for a Monster.

On the way home, I thought I'd ride past Roxy's work. She obviously heard me coming, because she was at the window waving madly    I stopped for a chat and she caught me looking more naked than usual - I was in such a rush to leave, I didn't bother putting the belt covers back on 

Anyway, by the time I got home, I reckon she was running better than ever. Even with the old plugs (which were new a few months ago).


So, I'll put it down to bad fuel, and the timing.