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Discussion Starter · #1 · (Edited)
help with knocking! NOT PLUGS!!

Mechanics..help!

So I've got a 2005 SV650s (i know it's a suzuki, but i've got a 636 too and i'm kinda partial to kawiforums...) and I have a knocking problem. It's a v-twin, by the way, in case you didn't know. So when the bike is running, either in neutral or in a gear with the clutch pulled, if I snap the throttle, the motor knocks one time before it starts accelerating. Only once.

When I'm riding it, if I accelerate smoothly, there are no problems, but if I get on the throttle hard, it will make a slight continuous knocking noise until I either let off or the bike catches up to the amount of gas I've given it.

That is the best way I can describe it. Could it just be that the timing is off? If so, can anyone explain how to adjust it? If not, what else could it be? If I can't figure it out, I'll have to take it to the stealership, but I'd rather fix it myself.

Thanks
 

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What grade of gas are you using (octane)?
 

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Discussion Starter · #3 ·
been using 87. that's what the manual calls for...well a minimum of 87. i put 89 in it last night when i filled up. i dont think octane is the problem, though. does the timing get off easily on these things? the bike's only got 41XX miles on it...

[Edit]: This is only the second time I've filled the tank, so all I know is 87 octane. The gas station I filled up at last night is 2 miles from the house, so I didn't really get a chance to see if the higher octane did anything.
 

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Discussion Starter · #4 ·
bump
 

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Powerhungry
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i think my 4wheeler does the same thing. under a load, with too low of rpms, i get a pretty solid knock also. but, its only at those specific times. ive never really worried about it.

any way you can get a sound clip?
 

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using a higher octane fuel may help, though it might not be the cause, or fix of the problem. Maybe something has slipped in your timing somewhere? or maybe the last service it had, they timed it incorrectly? If using a high octane fuel fixes it, I'd leave it at that. By high, I mean around 98. If something has fucked up though, it could have slipped to the degree that no octane of fuel will stop knocking.
 

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Powerhungry
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spark knock is usually a higher pitch. sorta tinny sounding.
but, agreed, if higher octane fixes it..than it was spark knock. but...i really doubt thats it..

altho, without hearing it..i cant say for sure either way...
 

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Discussion Starter · #8 ·
it's gonna be hard to get a sound clip of it, but i'll try.
 

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does it happen even after the bike is warmed up? my brothers vulcan has the same issue sometimes. i just know not to gas it without "warning" the motor. silly fuel injection and computers. just go back to carbs :thumbup:
 

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i was gonna suggest your spark plugs could be fouled...its probably misfiring, which creates the knock, you might also have fuel filter issue's, so yes, using a cleaner fuel is better
 

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Discussion Starter · #11 ·
does it happen even after the bike is warmed up? my brothers vulcan has the same issue sometimes. i just know not to gas it without "warning" the motor. silly fuel injection and computers. just go back to carbs :thumbup:

yeah it does it even when i'm warmed up.
 

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Discussion Starter · #12 ·
i was gonna suggest your spark plugs could be fouled...its probably misfiring, which creates the knock, you might also have fuel filter issue's, so yes, using a cleaner fuel is better

well a lot of people have suggested spark plugs, so i'll change them out this weekend. the bike doesn't have many miles, though. they are 3+ years old now, though, so I guess it won't hurt to change them.


can anyone tell me how to check the timing? anyone have any links to DIY's??
 

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whens the last time you had the valves checked?? & have you checked the CCT???

wait do the twins even have a CCT??
 

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Discussion Starter · #15 ·
whens the last time you had the valves checked?? & have you checked the CCT???

wait do the twins even have a CCT??

i've never checked it. i've only had the bike a month or so and am working on it slowly cuz i'm in school right now.

how do you check the valves? i thought timing might be off. how do you check either/both of them? my dad told me you check timing with a timing light (go figure). i don't know about valves. i seem to remember a DIY on kf, though. did someone put one up for valve synch?

i'd like to do the work myself to save money and also because i like to work on bikes. any guidance?
 

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checking valves and timing is a bitch unless you have the proper tools, and they are expensive...and to have a shop do it is also a pain in the ass, cause of laber...i've had to check timing on a damn golf cart the old fashioned way of just taking it apart...and it took damn near 3 hours to pull everything apart and check it and get it right...

but if you have the time and feel the need, you should be a service manual for the bike and it will show you

Also, spark plugs can foul up just from sitting too, so if its 3 years old and has few miles on it, that could be the case.
 

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Discussion Starter · #17 ·
cool, thanks. i've got the shop manual for the SV but it's not the most helpful one i've ever seen.

i'll change the plugs this weekend and i'll try to get a vid of it up tonight. i just got back from school and ama going to chill for a few minutes..
 

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Discussion Starter · #19 ·
wait, it sat for 3 years? what does the gas look like? has it been drained, and the tank flushed out? could be alot of nasty old fuel, and water in there.

no, i don't think it sat. if i knew that, i would have checked the gas. the kid i bought it from said he rode it around.
 

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no, i don't think it sat. if i knew that, i would have checked the gas. the kid i bought it from said he rode it around.
ah. ok, i read back. i just seen 3 years, and was thinking it SAT, that long.

does it do it, while in neutral too? or only when riding, with a load against the motor?
if it will do it in neutral, record a sound clip.
 
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