Noise On Left Side?

Hey guys. I have a "Noise" In the left side of my engine. The older techs at my work say its normal? Sounds to me like the primary drive chain inside the engine. And I have been told this is what it was. Wanna see what you guys think.

Is this normal?


BTW...when idle is at 1300 or more it smooths out till high rpm range only under 1300 R's.

Well, IMO idle should be around 1300. These are old machines so can´t expåect them to run as smooth as new, modern bikes. Also you could check the cam chain tensioner. It might be stuck thus leaving too much slack.

Is this a "rattle" that goes away over 1300 rpm? If so, check your starter clutch for loose bolts. Pull the stator cover and reach behind the rotor and see if you can move the starter clutch. If you can move it any at all, pull the rotor and tighten the bolts, or replace them if they show any damage. You will need to loctite them too. I am assuming the 750 4 has the same set up as the 1000 4....chris3

ill check that out next chance I get...

From what you describe it does sound like primary chain noise, my 650 does it too - only cure is a new primary chain which will require splitting the cases. The noise is fairly normal for the 650s/750 fours and not really anything to worry about, I have never seen or even heard about a primary chain breaking.

The 650s/750 fours do have a different starter clutch setup than the big bikes, they have the starter clutch sitting on the secondary shaft behind the crank - the primary chain is what ties the the crank and the secondary shaft together through the starter clutch.

The pic below shows the primary chain and starter clutch on a 650 engine with the secondary shaft half removed - as you can see the chain is about an inch wide and not likely to snap.

Thats what i figured...run er till she blows...lol