Hesitation, surging and crap mpg.

[Lawrence]

Hi all, my hesitation problem has got significantly worse recently.  MPG has dropped (140 miles put me between E and 1/4), it still hesitates badly when opening it up and it's also started running really rough on constant throttle.  For example, get up to 5-6k in a lower gear (it's still there in high gears, just less noticeable) and you can feel it surging like it's running ok for a second, then missing, then ok etc.  After my 50 mile run home downpipes 1 + 2 were 220C and 3 + 4 were 170 so something definitely isn't right there.  It's also spitting a lot of black shite out of the exhaust which is presumably my hard earned, half burnt petrol  :'(

It's over-due a service so I want to get oil + filter, air filter, plugs changed this weekend - I changed them ages ago when it was hesitating, but not this bad and none of them had any effect - but what else can I check?  Carbs have been balanced recently and were as close as we could get them and it's had new plug caps a week ago.  I also trimmed the leads recently, couple of months back.

I would like to get a known-good set of carbs on it as I have a gut feeling that they're the problem but a) don't know much about them and b) use the bike every day so can't really afford it to be off road for any amount of time (unless I can borrow the blackbird again, maybe this is a good excuse )

So, anyone got any idea of things I can try?  Hopefully this won't turn into another Red98-style epic....

TLR
Bike hesitates, what's broken?

Ta very much 

[Lawrence]

Also, CR8E or CR9E plugs?

[darrsi]

Try a quick TPS check to eliminate it.

[elbrownos]

CR8E for UK
This is the best deal I could find when I bought plugs a few weeks ago. £17.20 for 4
http://www.ebay.co.uk/itm/1x-Arctic-Cat-...OC:GB:3160
How did you measure your downpipe temperatures?

[Lawrence]

TPS check was done when we did the carbs, was fine.

Temperatures were taken with one of these

Ordered some stuff for the weekend.  I did take #1 plug out yesterday and the ceramic was a nice brown colour, I haven't checked 3/4 but I will now...

#4 is exactly the same as #1.  It was a bit rusty round the bottom though (oo-er) so I'll check the drain holes when I put new plugs in too.

[darrsi]

Mine was fine too, then checked again recently and was out, not sure why?
It may not be your main cause but if it's set wrong it does make the bike jittery so won't help matters, so check it anyway, it only takes seconds to do.

[red98]

yep check the colour of the plugs...nice golden brown is what you want...when the carbs were balanced did you take them off and check/clean the jets.....check air filter for condition and blockages.....that should keep you busy for a while ...

[darrsi]

Black smoke > burning fuel > bad MPG > hesitation


Seems to point towards a blocked air filter?

[red98]

Black smoke > burning fuel > bad MPG > hesitation


Seems to point towards a blocked air filter?

thats what iam thinking DARRSI  [size=78%]........service should have been done before the balance to get the best results [/size] :\ might be worth checking again after you have serviced it  [/size][size=78%] [/size]

[darrsi]

I s'pose if you balance the carbs when the fuel/air is wrong you're actually making things worse?

[red98]

could be.....well worth checking again,even just to cross off the list 

[Frosties]

I'm thinking more along the lines of coil pack(s). Less noticeable above 6k Rpm due to changing over to main jets on the carbs......just my 2p worth.

[darrsi]

Shall we just cut out 50 odd pages and say it's the regulator?  :lol

[red98]

Shall we just cut out 50 odd pages and say it's the regulator?  :lol

:lol  no no no no...thats just not fair  :\ ..........service items,carb balance and then parts swap....its the cheapest way 

[nick crisp]

[quote author=darrsi link=topic=10010.msg103435#msg103435 date=1379968979]
Shall we just cut out 50 odd pages and say it's the regulator?  :lol

:lol  no no no no...thats just not fair  :\ ..........service items,carb balance and then parts swap....its the cheapest way 
[/quote]


More like just an excuse to buy another Fazer...

[red98]

[quote author=red98 link=topic=10010.msg103521#msg103521 date=1380010783]
[quote author=darrsi link=topic=10010.msg103435#msg103435 date=1379968979]
Shall we just cut out 50 odd pages and say it's the regulator?  :lol

:lol  no no no no...thats just not fair  :\ ..........service items,carb balance and then parts swap....its the cheapest way 
[/quote]


More like just an excuse to buy another Fazer...
[/quote]




:lol :lol  a very good excuse,fooled swmbo  .........but thats not hard  :rolleyes

[Lawrence]

I'm thinking more along the lines of coil pack(s). Less noticeable above 6k Rpm due to changing over to main jets on the carbs......just my 2p worth.

Could be, would be worth finding a known-good set to try out.

I'll do a compression test too at the weekend, may well not have the time before then.  I have run it without an air filter to see if it was that causing the problem but it was exactly the same.  Looking at my notes the air/fuel filter were done 21k ago so probably due by now 

[darrsi]

[quote author=Frosties link=topic=10010.msg103418#msg103418 date=1379967394]
I'm thinking more along the lines of coil pack(s). Less noticeable above 6k Rpm due to changing over to main jets on the carbs......just my 2p worth.

Could be, would be worth finding a known-good set to try out.

I'll do a compression test too at the weekend, may well not have the time before then.  I have run it without an air filter to see if it was that causing the problem but it was exactly the same.  Looking at my notes the air/fuel filter were done 21k ago so probably due by now 
[/quote]

Sounds like K&N time 

[Lawrence]

Part way there...

Took the coils off to check resistances, checked first one and it was ok.  Checked the caps (NGK SD05Fs that went on a few weeks back) and they're 5k ohm, which is half what Haynes reckons they should be.  Checked the originals, after digging them out of the bin, and they were all 10 ± 0.4 Kohm.  Stuck them all back on, re-assembled and it's much better than it was.  Still hesitates around 7k but pulled through it and then right up to 12k.  Shall see what the mpg is like tomorrow, hopefully it'll be better as it's costing me an extra £15-£20/week at the moment.

Oddly enough I don't remember it getting worse when I fitted them otherwise they'd have come straight back off  mash 

These are the ones I got and as it turns out they're wrong so don't buy them.

[darrsi]

Part way there...

Took the coils off to check resistances, checked first one and it was ok.  Checked the caps (NGK SD05Fs that went on a few weeks back) and they're 5k ohm, which is half what Haynes reckons they should be.  Checked the originals, after digging them out of the bin, and they were all 10 ± 0.4 Kohm.  Stuck them all back on, re-assembled and it's much better than it was.  Still hesitates around 7k but pulled through it and then right up to 12k.  Shall see what the mpg is like tomorrow, hopefully it'll be better as it's costing me an extra £15-£20/week at the moment.

Oddly enough I don't remember it getting worse when I fitted them otherwise they'd have come straight back off  mash 

These are the ones I got and as it turns out they're wrong so don't buy them.

Loads of us have got them, including me?