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View Full Version : Wet Misfire & Starting Trouble.


fri-sv
03-01-08, 12:54 AM
Hey, im new to the forum, but was hoping some of u might be able to advise on a problem ive been having with my bike recently, ive had a look at previous posts but cant quite find an exact problem like ive been having.

basically since i got the bike in june, an sv650 99' (curvy) when its got wet, from rain or from been washed, the next time i came to start it i have had quite bad starting problems, a misfire i think, where only one cylinder has been firing. but it always sorted itself out after i turned it off waited half an hour and started it again.

last week it happened again and this time it wont get going properly at all, it turns over fine but wont catch, so i gave it a little bit of throttle and it eventually did, then it will hang at 3500 revs on the choke and there doesnt seem to be a problem. but as soon as i back the choke off it seems to misfire, if i leave it it stalls, if i rev it, it revs really slowly, and then sometimes the exhaust starts popping lots like its backfiring loads. ive tried keeping it on the choke for longer and shorter periods of time but as soon as i let it off it starts having problems, and its difficult to get it started, although it does seem to run ok on the choke at first once i eventually get it started. if i keep the throttle open a long way it will keep running but doesnt fire properly, i also noticed that if i do rev it, the revs build up much slower than normal, but at 6000revs the other cylinder seems to suddenly fire up and it revs properly.

sorry about the long post i hope that makes sense, ive been trying to start it lots and am getting quite worried about it now, any advice on what it could be causing the problem or how to rectify it would be greatly appreciated, thanks alot.

ASM-Forever
03-01-08, 01:04 AM
Search for water in the front plug....cured with either a fender-extender/lube. :)

Its possibly the most infamous issue with the SV...so there will literally be more info than is possible to read.

IMHO there may be more to it than that, but from the little you have said, i can't diagnose further.

ASM-Forever
03-01-08, 01:05 AM
Double post- meh.

fri-sv
03-01-08, 01:07 AM
sorry if i didnt give enough info, am not really very technically knowledgeable about things yet, would it help taking the plug out cleaning/replacing it maybe?

ASM-Forever
03-01-08, 01:21 AM
Don't worry, i'm no mechanical god either. ;)

Search for "water front plug" and that should get you a whole heap of advice.

fri-sv
03-01-08, 01:30 AM
thanks, found some similar stuff, dont know why i couldnt find it when i searched earlier, will have a go at getting the plug out tommorrow, hope this isnt a stupid question, but do i need to take the radiator anf fairings off or can i get to the plug without removing anything else?

ASM-Forever
03-01-08, 01:32 AM
I didn't have my SV long enough, before i wrote it off, to do much spannering. However i'm pretty sure that with the right socket the rad stays on.

Stig
03-01-08, 07:50 AM
You can leave the radiator all connected up (hoses), but you will need to undo the mounting bolts so you can drop it the required inch or two for access.

It does sound like a wet front plug and yes taking it out and giving it a clean will help no end. The best thing you can do is get fender extender to stop the water getting that far up the engine.

Biker_Billy
03-01-08, 09:31 AM
When you are putting the plug cap back on, it might be worth coating it in silicone to stop the water ingress. I had this on mine from washing it, touch wood, using silicone has stopped it so far...

As others have said, a fender extender will be very useful to stop the spray when riding.

Billy.

dyzio
03-01-08, 09:41 AM
click1 (http://forums.sv650.org/showthread.php?t=81046&page=2)
click2 (http://forums.sv650.org/showthread.php?t=97695)
hope this will help

sv-robo
03-01-08, 09:45 AM
Search for water in the front plug....cured with either a fender-extender/lube. :)

Its possibly the most infamous issue with the SV

most folk would agree with that.

Biker Biggles
03-01-08, 08:40 PM
Thats all good stuff that any SV owner needs to know,but I think your problem is different.A wet front lead/plug will misfire because the spark is shorted out,so the bike wont run better on choke.What you describe is a very lean mixture,possibly caused by an intake air leak.Are your carbs and airbox seated properly,or could there be air getting in somewhere?And yes,you should get the plugs out to see what they look like.They will probably tell you what is wrong.