Engine Tapping Behind Clutch

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]

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.

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]

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

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.

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?

Originally Posted by Torn-Thorax

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]

Originally Posted by Torn-Thorax

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.

[TSM]

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.