Torsti

E: Solved. It was the primary drive damping gear.

Ok. Greetings from Finland.It's my first post here.

I bought my VTR a couple of weeks ago and I've wondered a strange "knocking" noise when bike idles. Noise cannot be heard when driving but it's always there when bike idles. Even if it is cold or warm. I haven't had a chance to compare my bike to another.

Idle noise

VTR whining after repair

inderocker

Does it go away when you disengage the clutch?
Does it go away when you bring up the RPM's from idle?

Torsti

No. Pulling clutch does nothing to sound.
Forgot to mention, valves have been checked about 8000 miles ago. Everything was fine there.

Torsti

It can be heard to about 3000rpm. Above that it cannot be heard or goes away.

inderocker

Sounds like CCT's (cam chain tensioners) to me. Do a search for more details.

Torsti

I've read a lot about CCT:s and I've already ordered new tensioners. Maybe I'll check the valve clearances even though they should be checked. At least I've been told so.

8541Hawk

If the noise is just at idle and low RPM it could be the carb slides opening and closing. They are rather large and do make a "hollow" clunking noise at low RPM which is just a normal SH noise.

If you have a stethoscope (or the old screwdriver handle trick) you can try to locate where the noise is coming from. But a CCT "should" make noise all the time.

Changing the CCTs is a good thing though. Not so much because of all the paranoia caused by some of the threads here but because you really don't know how they were treated by the previous owner. Checking the valve clearance is also a good thing while your are in there and I always double check that on a new to me bike.

You didn't say if you were installing auto or manual CCTs. IMHO either works fine. There are just a few "rules" if you run the auto (or stock) CCTs. 1) Don't let the bike sit and idle on the side stand. 2) Don't slam the throttle shut from high RPM. 3) Don't lug the motor, or try to keep it above 3k RPM in most situations.

Have fun with your new bike.

Torsti

The noise comes only when the bike runs idle. I tried to pinpoint the noise with a large screwdriver without significant results.

I bought stock CCT's, because I didn't find APE's in European Union on eBay. Finnish customs doubled the price of Factory Pro-made emulsion tubes to my previous GSF1200, so that's why I didn't buy APE's from USA.

Tweety

Make manual CCT's out of the stock one's instead... Much better and a lot cheaper...

Torsti

Well, I'll try new ones first as they are already ordered.

8541Hawk

I would bet it's the carb slides then, try putting the screwdriver right on the carb bodies......

Torsti

New CCT's installed and valve cleareances checked. All OK, but the sound is still there. I think the next solution is louder pipes.
It was a bit difficult to align marks for front cylinder TDC pushing the bike on sixth gear.

I found out that Honda had made front TDC aligning mark to rear cylinder camshafts. One crankshaft turn is half turn at camshaft. So 1 1/4 crankshaft turns, which is required to put front cylinder to TDC, is 5/8 turns at camshaft. Just put the little circle above R-I mark pointing left after you have set the rear cylinder to TDC. Much easier to look for that mark than looking the tiny F-mark on flywheel. Of course you have to look the R-T mark on flywheel when setting the rear cyl TDC.
Hope you understood my meaning, since I'm not native english speaker.

nothing

well if the cct's didn't do it, and you bought the bike just a couple weeks ago and didn't have the valves check 8000 miles ago yourself, that would be my next plan of action.

8541Hawk

........ Carb Slides.........

Torsti

It was the clutch. Noise goes away when clutch is disengaged in first gear. I did not notice this before because I tried to engage and disengage the clutch lever in neutral position.

Torsti

Finally solved, thanks to www.superhawkforum.com