View Full Version : Engine Tapping Behind Clutch
Torn-Thorax
03-01-07, 02:41 AM
So It took my sv2000 into the local shop last week, to get fixed whatever was making this troubling racket, and they tell me today that they have adjusted the fuel mixture to resolve "poor running and some backfiring" and that now the tapping is "much quieter"
First off, this garage is the best place around, I trust them, but people here at the forum know thier bikes. I'm told by the garage that "high mileage engines just make some noise" and that I should not worry. (By the way, the bike only has 18k miles on it) The valves were checked, and are fine, and the cam tensioner was reset with no change to the problem.
It there another common noise that might be associate with poor running? (the carbs were balanced, just not with a good mixture)
Do I keep riding it with this faint tapping noise?
Do I have them tear open the rear cylinder and poke around the cams?
-Getting expensive
northwind
03-01-07, 09:52 AM
I'd be very skeptical, if I was you. "High mileage" is just nonsense at 18,000 miles... And the mixture adjustment on the SV carbs is only for idle and very low revs, the only way to adjust the mixture otherwise is to physically change parts... Not saying they don't know what they're doing, but a lot of people presume that the mixture screws are some sort of "master" adjuster, which they're not. It could well be that it was off at idle and they've fixed it- shouldn't cause noise though.
But, bikes do make some noise, a bit of rattle's fine really. So it might be nothing to worry about.
Torn-Thorax
03-01-07, 06:05 PM
Well the guys also said they had to drill the carbs. Something about the o2 censors i think. The bike was backfireing alot and they said that was fixed, so they must have done something other than mess with the idle adjuster. I just replace the choke cable and cleaned the carbs last month, so i know its not dirtyness. (these problems existed before last months work)
Anyway. I havent actually heard the current level of engine noise. I pick her up on saturday. Might post again then.
TT
northwind
03-01-07, 09:47 PM
You do not have 02 sensors :) But to be fair, it does sound like they did more than just balancing it.
I had a rattly clutch once, i found out that 2 of the barnett springs i had in had broken, they were only around 1000 miles old
Just an idea, not sure if its the same problem as yours :?
Torn-Thorax
04-01-07, 03:34 AM
now that you mention it, the mechanic did say he thought it might be Barnett springs. He said it was not, and that the noise was coming from inside the engine - right behind the clutch.
Torn-Thorax
06-01-07, 05:59 PM
Ok, I picked up the bike an hour ago and talked to the mechanic. He said he drilled out the O2 adjuster screw plugs, and adjusted the mixture. The engine noise persists, and its really not any quieter. Power has noticably increased, and it runs better overall, but the noise still bothers me even thought the mechanic says its nothing to worry about. The noise used to be isolated but now seems to origonate from both cylinders. Gah, I cant spend anymore cash on this.
When the they checked the valves, would they have noticed if there was a broken spring?
Do i really just drive on with the noise?
netsurfer
06-01-07, 07:03 PM
even thought the mechanic says its nothing to worry about.
Will he stand over it if the engine blows up due to whatever the noise actually is?
I'd say try for a second opinion somewhere else.
Pete
northwind
06-01-07, 07:23 PM
Ok, I picked up the bike an hour ago and talked to the mechanic. He said he drilled out the O2 adjuster screw plugs, and adjusted the mixture.
That makes sense- that's the idle mixture screws he's playing with. Did he suggest that it'd have noticably affected the entire range? if he did, you need to not use that garage ever again :) If not, then he's probably done you a nice little tweak there- US bikes come with undersized pilot jets for emissions reasons so a tweak on the screws can help pickup from idle. They can be set up wrong fromteh factory, and very occasionally wander off setting as well. But (yes, overstating here) those are idle mix screws and have only the tiniest imaginable effect anywhere over a couple of thousand RPM.
Have you got an aftermarket air filer, since i put my K&N and then the BMC Race (also dont have the foam on the underside of the tank), i hear more rattling from the engine, but its the noise from the valves back trough the airbox along possably with the cam chains rattling. Mine is on 28-29 and its still running fine engine wise.
Torn-Thorax
07-01-07, 05:36 AM
Northy, he didnt say anything about the entire range, but the improvent in the bike's running is miraculous. The backfire only occured when I opened the choke during warmup. (so at low RPMs)
No all intake stuff is stock. But my air filter was aparently in bad shape.
Could all the backfiring and lack of air caused some kind of damage? Becuase my noises didnt start untill put this other set of carburetors on this thing about 1000 miles ago. (maybe i should have mentioned that before)
Torn-Thorax
07-01-07, 06:24 AM
Oh, and one more thing. The replacement carbs are ones from a California bike with the EVAP system. I plugged the EVAP hole on both carbs thinking that would be all that is required to make it just like its predecessor. I hope that was ok.
I'm so exhausted with the technical problems of this bike. But I guess its my own fault, as I should have been a more cautious buyer.
What was wrong with your old carbs? and were are they?
Torn-Thorax
07-01-07, 04:19 PM
I had a cracked float bowl, and it was cheaper to just buy a whole set of used carbs off ebay.
northwind
07-01-07, 10:44 PM
Northy, he didnt say anything about the entire range, but the improvent in the bike's running is miraculous. The backfire only occured when I opened the choke during warmup. (so at low RPMs)
No all intake stuff is stock. But my air filter was aparently in bad shape.
Could all the backfiring and lack of air caused some kind of damage? Becuase my noises didnt start untill put this other set of carburetors on this thing about 1000 miles ago. (maybe i should have mentioned that before)
I reckon that the biggest difference you're feeling is from the carb balancing- a bit of a backfire with the choke isn't that uncommon, since basically what the choke does is give you a horribly rich mix for a while :) It almost certainly won't have caused any damage though. It's also quite possible you had a bad seal around one of the intake mountings, that's very easy to do and could cause misfires- and it'd be most evident at lower revs.
I'm still skeptical about the rattle, and it really baffles me to hear your bike described as high miles, but I'm not convinced that your mechanic's incompetent any more, on the plus side ;)
Torn-Thorax
08-01-07, 03:04 AM
I balanced the carbs, not more than a month ago. Really, I just want to know what the hell that noise is, and if its going to kill me when the engine siezes as I'm driving down the interstate. From all that ive read here on the forums, the sv is of quality build, and as long as you give it oil, it shouldnt sieze....hopefully.
...the sv is of quality build...
:lol: :lol: :lol:
Noises form an sv engine!! Mine rattles pops n bangs quite happily. I personaly wouldnt worry about it. I feel that its quite a noisy engine? I have a rattle at the momnet. I thought it was the clutch but its a bolt on the exhaust. Sounds like a very quiet Dry clutch.
AS said before i dont think a rattle would be caused by any thing in the carb region.
Somethings that havent been asked.
Does the rattle get louder with engine speed?
Does the rattle speed up, or is it constant with engine speed?
Is it really noticable when riding or more so at idle?
Does the rattle disapear when the clutch is pulled in?
Torn-Thorax
08-01-07, 05:09 PM
Rattle does speed up, but does not get louder.
Does not dissapear when clutch is pulled, it might be quieter though. I will check when I go out today.
Torn-Thorax
08-01-07, 05:27 PM
And no, it's not noticable when riding.
northwind
08-01-07, 07:12 PM
Right, well, if it was mine... I'd weigh up the cost of splitting the engine and having a root around inside, with the cost of a new engine, and then I'd ride it as it is. If there's something drastically wrong with it that'll destroy it some day, well, chances are it's not economic to repair anyway with a used motor being fairly cheap. And the chances are it'll not be a problem anyway. So I'd cross my fingers and ride on, I reckon.
But, that's just my opinion, wouldn't want it to sound like a recommendation :)
Sorry to be a little simplistic. Its not something like one of the bolts on the clutch come loose and clipping the inside of the clutch cover? Before splitting the engine, id check everything simple 1st. Do you know anyone that knows about bikes that could give you a second opinion? What could be worrying you others wouldnt wouldn't think twuce about. Is there anyway of recording the sound? Sometimes theset hings work.
Torn-Thorax
09-01-07, 12:48 AM
There is no difference when the clutch is plulled in, I checked.
The mechanic disassembled the clutch at the garage, found no problems.
Yea I can record the sound, ill figure something out tomorrow and PM you.
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