Knock knock

[Lord Stig]

I finally isolated where the noise is coming from on my AT this morning. It's coming from the nearside of the top end of the front cylinder, and the sound is a rhythmic knock. I'm assuming I have lateral play on the cam, though I haven't yet tried the trick where you listen to see if the sound changes when the bike is leant one way or the other. I was wondering how common this is in ATs - who else has had this experience? If you've had it and it turned out to be something less serious than the cam you could cheer me up. Not being of the sunniest dispostion this morning I doubt anyone will though.

The cam runs directly in the head, so unless I get phosphor bronze inserts put in I'll have to source second hand heads and cams. The inserts route and the replacement heads will both be expensive and will mean the bike being off the road while I still need it. I'm thinking this expense and hassle on an engine and gearbox that has done 81,000 miles might not be so wise. Does anyone know of a low-ish mileage (i.e., 50,000 or less) complete engine for sale? An engine swap might be the quickest and, in the long run, cheapest solution.

And no, I don't want to put a Fireblade or Firestorm engine in. If anyone has used a 600 or 650 Transalp I'd be interested to hear what problems there were though.

Stig (AKA Marvin the paranoid ATdroid).

[iswoolley]

Bad news indeed Mr Stig. Does seem like more wear than we'd expect from an 80k engine. I take it you've changed the oil occaisionally, and not run the bike upside down for a prolonged period?

[Lord Stig]

Yep, oil every 4,000 on the dot, no upside down stuff, though does the Wall of Death count....

The engine is normally run in two hour blocks (less start up wear than a bike with fewer miles), but a lot of that is 80-90, so a brief oil blockage could have caused broblems. I had a similar noise a while ago though, and it went away (I followed Yen's advice and turned a deaf ear). I've never heard of intermittent wear, but I believe in the Surrey Panther.

There's an engine on eBay at the moment and I've put out feelers for ones in breakers too. I should be able to find one without too much of a problem, and I don't think the demise will be that rapid (I hope).

Stig

[YEN_POWELL]

I'd ignore it again. Listening closely to the engine (especially in a garage) can make you hear horrible noises. Have you tried the screwdriver or metal rod or stethoscope to islote the noise further?

Lateral play on the cam was infamous on big Suzuki GS750 and 850s and they lasted forever.

[Lord Stig]

Not yet Yen, but the noise is REALLY easy to locate by ear even without being an owl. It's a definite knock, and I can't think of anything else in that location that could do it, although it does seem slightly odd that the offside is quiet (maybe it relates to some odd AT interpretation of the offside rule). Probably because the cam chain runs in that side.

Strangely enough I came across a 'fix' for V4 Hondas here http://www.magnariders.com/html/TipT..._Bulletin.html. This is nothing more than a hole and obviously doesn't cure the wear, but does make the sound go away. I don't think it's going to explode in the near future, so I probably have time to locate a less worn engine. If it goes away again, all the better!

Stig

[YEN_POWELL]

I know I keep saying this, but that is where the deep plug is, the cause of me getting new camchains a few years back. However, I remember you , but I thought I'd mention it anyway.

[Lord Stig]

Yeah I'll check again in case it's worked loose some how. It's a spot on position for the front plug, plus I recently had it out to do the balancing. Maybe clutching at straws, but it feels better to clutch at something rather than nothing. What did yours sound like though? This sounds like someone tapping the valve cover casing with their knuckle (or what I imagine that would sound like if the casing was free from the head). It'd be ironic if you changed the chains and I changed the whole engine just for a loose plug!

Got new tyres ordered for Saturday, hell I might as well buy some new wheels....

Stig

[Carport]

Strangely enough I came across a 'fix' for V4 Hondas here http://www.magnariders.com/html/TipT..._Bulletin.html. This is nothing more than a hole and obviously doesn't cure the wear, but does make the sound go away.
Stig

This fix from Honda was also used on VFR750's right up until the last ones in about 1997.

Mine was done under warranty and worked a treat

[YEN_POWELL]

Yeah I'll check again in case it's worked loose some how. It's a spot on position for the front plug, plus I recently had it out to do the balancing. Maybe clutching at straws, but it feels better to clutch at something rather than nothing. What did yours sound like though? This sounds like someone tapping the valve cover casing with their knuckle (or what I imagine that would sound like if the casing was free from the head). It'd be ironic if you changed the chains and I changed the whole engine just for a loose plug!

Got new tyres ordered for Saturday, hell I might as well buy some new wheels....

Stig

Can't remember actually, I know it was really hard to track the noise down to a specific area though. Don't spose you've got a leaking tappet inspection cover or a hose fallen off or a carb balancing screw missing?

[Slimie]

If the fix for the other bikes just makes the noise dissapear it would seem that there's no danger of the engines self-destructing so I'd go along with Yen and suggest ignoring it.

Whenever I ride for a mile of two without earplugs ('cos I forgot!) I think my bike's about to fall apart. As soon as I put them in everything's peachy!!

As someone much wiser than me once said, "Just ride it"!

Cheers
-Simon

P.S. If, heaven forbid, it does explode no guarantees have been expressed or should be inferred in the above, oh and YMMV!