XS650 engine rattle - help needed please

[surfer]

My xs650 has developed an engine rattle sound. It seems to be coming from the top of the engine. Blowed if I know what it is. Can anyone help please?

It isn't a cam chain as I have just had a new one put in. The cam chain is adjusted properly and this has been doubled checked. The old one was really worn and knackered. Compression in both cyclinders is ok. The bike has no trouble in acclerating or reaching its top speed.

The only things that I can come up with that it might be are piston slap which is unlikely as the rattle sound does not appear to be consistent, and or worn cam bearings. The cam shaft itself appears fine.

What do you reckon? And should I be really really worried?

[Macktheknife]

As I recall it they often had a rattle even when new, if your compression is ok then it is unlikely to be piston slap, possibly cam bearings but what kind of rattle?
Did the rattle start just after the new chain was put in? possibly a different adjuster used that is causing the noise.
Worry? give it a while and see if it settles, then decide.

[surfer]

As I recall it they often had a rattle even when new, if your compression is ok then it is unlikely to be piston slap, possibly cam bearings but what kind of rattle?
Did the rattle start just after the new chain was put in? possibly a different adjuster used that is causing the noise.
Worry? give it a while and see if it settles, then decide.

Cheers for the reply; will see if the noise settles down.

[Pussy]

You could remove the rocker cover ( easy to do with the motor still in the frame, just remove the top mount) and make sure the cam is dead central. It is possible that the cam may be slightly to one side. I saw this happen many years ago, with a consequence of uneven wear on the chain guides

[Motu]

Not likely cam bearings on an XS650,they have substantial double ball bearings each end.Pull the tensioner out and have a good look at it,they have a sprocket which runs un the chain,this could be worn or out of aligment,also check the chain guides......which you can't unless you pull it apart again.Check the advance retard mechanism for play,and also the shaft - this too runs in neelde rollers each end,they get dry and sticky.Rest assured that no noise in an XS650 is cause for concern,they are way over engineered and can be destroyed only by immersion in the crater of Mt Doom.

[NighthawkNZ:Me]

most likely one of the chain tennsioners needs a tweek... but as stated these were pretty rattlely even when new...

[Pussy]

Not likely cam bearings on an XS650,they have substantial double ball bearings each end.Pull the tensioner out and have a good look at it,they have a sprocket which runs un the chain,this could be worn or out of aligment,also check the chain guides......which you can't unless you pull it apart again.Check the advance retard mechanism for play,and also the shaft - this too runs in neelde rollers each end,they get dry and sticky.Rest assured that no noise in an XS650 is cause for concern,they are way over engineered and can be destroyed only by immersion in the crater of Mt Doom.

The 447 series engines ( about '74 onwards) didn't have a sprocket on the cam chain tensioner, it's just a rubber covered alloy guide, neither was the advance rod supported by needle rollers, just plain bushes. The early 256 series engines had what you described

[Motu]

Yeah,15 years with an XS1 is where I'm coming from.....

[Pussy]

Hey Surfer, try to work out what model engine you have. There were several different camshafts fitted to the 650s over the years, and several different valve clearance settings too. The 650 donk can sound a bit rattly with incorrect valve clearances. I've had three 650s over the years( many years ago) , TX650, TX650A, and XS650D. Great bikes, would love to get one at some stage again, for old times sake

[surfer]

Hey people cheers for the feedback.

The bike is a 1982 special, if that helps. Not sure of the model number.

I was told the valve settings are set at 3 and 6. But at some stage I should reset them to 2 and 4.

[surfer]

Hey people cheers for the feedback.

The bike is a 1982 special, if that helps. Not sure of the model number.

I was told the valve settings are set at 3 and 6. But at some stage I should reset them to 2 and 4.

I'll add a bit more to the above; I think it is a 1981 SH heritage special. it was registerd in 1982.

Would the inlet valves make nosie if they were set to .003 rather than .0026 in? If so will this damage anything if I enjoy the rattle sound?

[Alive]

You have an XS so you have probably already heard of Motorcycle Graveyard in Waiuku.

If not, give Andrew a call on 021 1068693... He specialises in XS's and knows a whole lot about them

[surfer]

Thanks for the reply, been there and done that. He wasn't sure what it might be, hence my post.

[Pussy]

I presume it is the electronic ignition model, with the oil level sight glass?

[surfer]

I presume it is the electronic ignition model, with the oil level sight glass?

It has the oil level sight glass but is a points system. (At some stage I plan to pop an electronic system in but need to save moolah first.)

I did have problems with getting an accurate wiring diagram for the bike as the wiring seemed to be an amalgamation of what was on the SH and late XS650E models (Clymer manual). I managed to make up a new loom which works just fine using the two diagrams.

I am slightly confused still as to the model; the engine number begins 5AP. Any ideas?