Sprint tapping noise

[bigbird]

Hi all
My sprint has just developed a tapping/raterling noise from the engine, it happens when im going along in gear and back off the gas between 2000rpm and 5000rpm,It sound like top end.
Im no expert so any advice would be great.

[zippythehog]

Does it make the noise with the engine cold only or also when hot?

When was the last valve adjustment?

It could also be a leak in the exhaust manifold/gasket area.

[bigbird]

Hi & thanks zippythehog

It does it when its hot or cold.The temp gauge does move but it never gets out of the cold range (is this normal?).I've not done the valves yet its on my todo list, I've only done 2000m since I've had it. It a real fine bike, real easy the ride and eats miles.

[zippythehog]

big,
I'm not a mechanic. My sprint seemed to run cold too. I recently had the fan come on after some city riding, so, I think they tend to run cold. The manual says that the thermostat should open at 85 degrees (I'm guessing this is Celcius).
About the tapping, since it does it all the time, I would think that it is a valve train problem. But since you say it only does it on trailing throttle, it seems the valve train would be an unlikely candidate. Maybe a leak in the induction side?
Another guess would be slack in the timing chain? I think that checking the timing chain tension is part of the valve adjustment service intervell (18k if I'm not mistaking).
zip

Re running cold, mine runs right down in the cold part of the gauge unless sitting in traffic when it rises to a third of dial before fan cuts in This appears to be normal

[RacingGreen]

Ditto on cool running with my 95.

[bigbird]

hi zip
cheers for the advice i think I'll start with a valve check and go from there.Thank saxman that make me feel better knowing your runs cold to.Do you think this might have something to do with the tapping noise (lack of lubrication)?and would covering part of the radiator help warm things up a bit?

[Toothpick]

Same cold running on my '95 Sprint.

[sailfish]

My gauge indicates "low" most of the time also. It's not so much that the bikes run cool, it's more that the gauge has poor resolution and really isn't all that useful.

Regarding the noise, it's probably time to take it in or dig in. Start with valve clearances and work your way out from there. Check everything, chain tension, the torque on the caps retaining the cams, the sprockets, etc. You haven't said how many miles are on the bike or miles since the last valve adj. Is this an 885cc machine? Might it be a 1998 model?

Good luck.

[bigbird]

hi sail
yes it is a 885 98/99 why do you know somthing i dont?

thank for the info, i like the idea of digging in.