Author Topic: Hesitation, surging and crap mpg. (Read 14939 times)

Lawrence · « **on:** 23 September 2013, 06:09:05 pm »

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....

TL:DR
Bike hesitates, what's broken?

Ta very much

Lawrence · « **Reply #1 on:** 23 September 2013, 06:18:23 pm »

Also, CR8E or CR9E plugs?

darrsi · « **Reply #2 on:** 23 September 2013, 06:18:36 pm »

Try a quick TPS check to eliminate it.

elbrownos · « **Reply #3 on:** 23 September 2013, 06:24:29 pm »

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-2009-366-4x4-Automatic-NGK-Yellow-Box-Spark-Plug-CR8E-Genuine-/390589778571?ssPageName=ADME:L:OC:GB:3160
How did you measure your downpipe temperatures?

Lawrence · « **Reply #4 on:** 23 September 2013, 06:33:31 pm »

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 · « **Reply #5 on:** 23 September 2013, 06:55:38 pm »

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 · « **Reply #6 on:** 23 September 2013, 07:11:31 pm »

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 · « **Reply #7 on:** 23 September 2013, 07:54:53 pm »

Black smoke > burning fuel > bad MPG > hesitation

Seems to point towards a blocked air filter?

red98 · « **Reply #8 on:** 23 September 2013, 08:00:06 pm »

Quote from: darrsi on 23 September 2013, 07:54:53 pm

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 · « **Reply #9 on:** 23 September 2013, 08:22:10 pm »

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

red98 · « **Reply #10 on:** 23 September 2013, 08:25:13 pm »

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

Frosties · « **Reply #11 on:** 23 September 2013, 09:16:34 pm »

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 · « **Reply #12 on:** 23 September 2013, 09:42:59 pm »

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

red98 · « **Reply #13 on:** 24 September 2013, 09:19:43 am »

Quote from: darrsi on 23 September 2013, 09:42:59 pm

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

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

Hedgetrimmer · « **Reply #14 on:** 24 September 2013, 09:24:46 am »

Quote from: red98 on 24 September 2013, 09:19:43 am

Quote from: darrsi on 23 September 2013, 09:42:59 pm
Shall we just cut out 50 odd pages and say it's the regulator?

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

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

red98 · « **Reply #15 on:** 24 September 2013, 09:29:30 am »

Quote from: nick crisp on 24 September 2013, 09:24:46 am

Quote from: red98 on 24 September 2013, 09:19:43 am
Quote from: darrsi on 23 September 2013, 09:42:59 pm
Shall we just cut out 50 odd pages and say it's the regulator?

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

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

a very good excuse,fooled swmbo

.........but thats not hard

Lawrence · « **Reply #16 on:** 24 September 2013, 10:37:22 am »

Quote from: Frosties on 23 September 2013, 09:16:34 pm

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 · « **Reply #17 on:** 24 September 2013, 11:00:45 am »

Quote from: Lawrence on 24 September 2013, 10:37:22 am

Quote from: Frosties on 23 September 2013, 09:16:34 pm
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

Sounds like K&N time

Lawrence · « **Reply #18 on:** 24 September 2013, 07:03:03 pm »

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

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

darrsi · « **Reply #19 on:** 24 September 2013, 07:19:36 pm »

Quote from: Lawrence on 24 September 2013, 07:03:03 pm

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

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?

Lawrence · « **Reply #20 on:** 24 September 2013, 07:21:29 pm »

That's why I bought them, they were recommended on here. Haynes says the resistance of the caps should be 10Kohm, those are 5. Swapping them back (and that's the only change that was made) had a huge impact on how it ran.

darrsi · « **Reply #21 on:** 24 September 2013, 07:33:22 pm »

That's very interesting!!!
I wonder if that might be a reason why my bike's slightly unhappy around the 3000rpm mark at lower speeds?
I've always blamed the short end can!

Gonna have to see if i've still got the originals to try, 'cos i'm certainly not gonna pay £52 each for new ones?

Lawrence · « **Reply #22 on:** 24 September 2013, 07:37:09 pm »

Sod £200 for a set, that's not far off what my bikes worth

I'm sure NGK will have something suitable, just a case of finding the right one.

Fazerider · « **Reply #23 on:** 24 September 2013, 07:39:01 pm »

As Darssi says, lots of us are using the NGK plug caps. There is nothing wrong with having a 5k ohm resistor instead of 10k, the thing's only there to stop radio frequency interference and the value is not critical. If those caps really are causing the problem it'll be due to breakdown of the insulation i.e a faulty one... or tracking due to dirt/moisture... or not having a good connection to the plug or ht cable. The value of the suppression resistor being 5k rather than 10 is not the problem.

darrsi · « **Reply #24 on:** 24 September 2013, 07:39:45 pm »

I never knew it was all so complex, i just thought caps were caps?