Low rev uneveness. - SV650.org

21-01-10, 08:23 PM

Hi everyone,

I have been suffering with the infamous front spark plug getting wet and mis-firing, I thought i sorted this after i read on here that if i clean, replace and refit the spark plugs that it would sort out this problem. It did, until it rained and it started to mis-fire again. Im getting used to the mis-firing in the wet, and doesnt bother me to much.

But.....

Lately ive been riding with friends in the dry with no problems, as long as i have the idle to around 1500-1600rpm, if i have it any lower it seems to "hunt" for the revs ( needle bouncing up and down from 1000 to 1300 ) and sounds very disconcerting. Also it seems that when ive been for a ride for a while and i drop off the throttle ( at a set of lights or whatever ) the rev counter drops to 2000 then slowly comes back down to idle after around 5-6secs. It also seems i cant wham on the throttle anymore as it jerks and buckaroo's me to calm down.

I have been reading around and been searching for quite a while now as to try and fix these problems. But ive had no luck and yet again call upon the .org to try and help me.

also ive come into some moneys and am thinking about getting a full engine service, Will this include sensor calibrating, cam adjustments etc? and what is a resonable price for this? Im also thinking about getting a PCIIIusb and getting it mapped by HM Racing in orpington, has anyone here delt with them? and would you recommend them?

Thanks for your time .org its much appreciated.

21-01-10, 11:32 PM

Hi

I think you need to do a bit more to properly solve the wet front spark problem - suggestions include adding a bit of grease to the seal around the front spark plug and/or getting a fenda extenda fitted (cheap and quite easy to do). do a forum search on it and you will find numerous threads.

I used to have the same problem but did both suggestions and haven't had it since even in the heaviest rain. riding the bike when it happens really isn't fun or safe so you'd best get this sorted before taking it out again.

i don't know about the dry problems you are having but someone with more bike knowledge will surely help out.

Spanner Man · 22-01-10, 07:30 AM

Good morning.

You don't state the mileage of your bike, but obviously if it hasn't been serviced for some time, it would definitely benefit from a good going over.
The cost of a good service would obviously depend on the mileage. For, if it is going to need it's valve clearances checked/adjusted it's going to take longer.
When sealing the front plug cap against the wet, it's important to make sure the cap is screwed onto clean HT lead. So, after removing the HT cap from the lead, carefully snip off 1/4 of an inch or so of lead before re-attaching the HT cap.

For your info, if I was just servicing the engine, I would charge between 2 & 3 hours labour. This would include checking, & adjusting the valve clearances, throttle body balance, TPS adjustment, coolant change, & spark plug & air filter inspection/replacement etc.

Cheers.

23-01-10, 03:14 PM

Cheers Spanner Man and Emcf, ill definatly do what you guys have suggested,
My bike has done just over 16000 miles now and went to the shop today and they said that doing vavle clearances and checking the resistances on the sensors etc will be around £120. and ill definatly get them to make sure everything else is okay.

Spanner Man, could my bike be idling lumpy due to my bike not having the baffle in, i have a Delkevic stubby pipe and i hardly ever ride it with the baffle in, could a PCIII sort it out?

23-01-10, 05:06 PM

warning - Plug Imminent

You maaaay need the throttle bodies synchronised, it should idle happily at 1300 rpm (my curvy idles at about that, no problems...when cold, it is at just over 1000 rpm). I dont think having just a baffle-less exhaust would mess up your fueling, certainly not to the extent you are experiancing.

Now, I may be starting to say this one too many times...but what the heck. Spannerman is a good guy to go to if you need some work done that you can;t easily do yourself - he's done a few things to my bike and I'm dead fussy about who gets their hands on my SV.

21-01-10, 08:23 PM	#1
BomBalong Guest Posts: n/a	Low rev uneveness. Hi everyone, I have been suffering with the infamous front spark plug getting wet and mis-firing, I thought i sorted this after i read on here that if i clean, replace and refit the spark plugs that it would sort out this problem. It did, until it rained and it started to mis-fire again. Im getting used to the mis-firing in the wet, and doesnt bother me to much. But..... Lately ive been riding with friends in the dry with no problems, as long as i have the idle to around 1500-1600rpm, if i have it any lower it seems to "hunt" for the revs ( needle bouncing up and down from 1000 to 1300 ) and sounds very disconcerting. Also it seems that when ive been for a ride for a while and i drop off the throttle ( at a set of lights or whatever ) the rev counter drops to 2000 then slowly comes back down to idle after around 5-6secs. It also seems i cant wham on the throttle anymore as it jerks and buckaroo's me to calm down. I have been reading around and been searching for quite a while now as to try and fix these problems. But ive had no luck and yet again call upon the .org to try and help me. also ive come into some moneys and am thinking about getting a full engine service, Will this include sensor calibrating, cam adjustments etc? and what is a resonable price for this? Im also thinking about getting a PCIIIusb and getting it mapped by HM Racing in orpington, has anyone here delt with them? and would you recommend them? Thanks for your time .org its much appreciated.

21-01-10, 11:32 PM	#2
emcf Guest Posts: n/a	Re: Low rev uneveness. Hi I think you need to do a bit more to properly solve the wet front spark problem - suggestions include adding a bit of grease to the seal around the front spark plug and/or getting a fenda extenda fitted (cheap and quite easy to do). do a forum search on it and you will find numerous threads. I used to have the same problem but did both suggestions and haven't had it since even in the heaviest rain. riding the bike when it happens really isn't fun or safe so you'd best get this sorted before taking it out again. i don't know about the dry problems you are having but someone with more bike knowledge will surely help out.

22-01-10, 07:30 AM	#3
Spanner Man Member Mega Poster Join Date: May 2005 Location: Sunbury Middlesex Posts: 1,396	Re: Low rev uneveness. Good morning. You don't state the mileage of your bike, but obviously if it hasn't been serviced for some time, it would definitely benefit from a good going over. The cost of a good service would obviously depend on the mileage. For, if it is going to need it's valve clearances checked/adjusted it's going to take longer. When sealing the front plug cap against the wet, it's important to make sure the cap is screwed onto clean HT lead. So, after removing the HT cap from the lead, carefully snip off 1/4 of an inch or so of lead before re-attaching the HT cap. For your info, if I was just servicing the engine, I would charge between 2 & 3 hours labour. This would include checking, & adjusting the valve clearances, throttle body balance, TPS adjustment, coolant change, & spark plug & air filter inspection/replacement etc. Cheers. __________________ Spanner Man http://stewarts-motorcycles.co.uk/default.html Last edited by Spanner Man; 22-01-10 at 07:34 AM.

23-01-10, 03:14 PM	#4
BomBalong Guest Posts: n/a	Re: Low rev uneveness. Cheers Spanner Man and Emcf, ill definatly do what you guys have suggested, My bike has done just over 16000 miles now and went to the shop today and they said that doing vavle clearances and checking the resistances on the sensors etc will be around £120. and ill definatly get them to make sure everything else is okay. Spanner Man, could my bike be idling lumpy due to my bike not having the baffle in, i have a Delkevic stubby pipe and i hardly ever ride it with the baffle in, could a PCIII sort it out?

23-01-10, 05:06 PM	#5
Alpinestarhero Guest Posts: n/a	Re: Low rev uneveness. warning - Plug Imminent You maaaay need the throttle bodies synchronised, it should idle happily at 1300 rpm (my curvy idles at about that, no problems...when cold, it is at just over 1000 rpm). I dont think having just a baffle-less exhaust would mess up your fueling, certainly not to the extent you are experiancing. Now, I may be starting to say this one too many times...but what the heck. Spannerman is a good guy to go to if you need some work done that you can;t easily do yourself - he's done a few things to my bike and I'm dead fussy about who gets their hands on my SV.