I have a 1989 sportster 883 that has just started making a rattling sound when under a load. The noise is not there while the bike is in neutral and it seems to go away at higher rpms. It only happens when the engine is hot.

Any ideas ?

 

check chain tension before digging deeper.

 

Thanks for the suggestion , but that was the first thing i checked and it is within spec.

 

Ping or knock maybe?
Have you changed anything latley?

 

+1 The described symptoms sound like ping.
Fill up with premium octane gas and see if that changes things. Drain the existing fuel is necessary.

 

Thanks for the suggestion but it's not a ping. it is knock at low rpms and only when the engine is hot. Maybe i should let it cool off more often ?

i only run premium.

 

No i haven't changed a thing. It only occurs when the engine is hot , and i run premium gas always.

It was really noticeable this past weekend while riding in the mountains , especially going uphill.

 

I'd check the primary chain again. Check it in multiple spots. Not just one.

 

Thanks , i took your advise and adjusted the primary chain. Turned the adjustment screw about 1/4 turn. Noise went away !

Thanks Again

 

Cheers!!