Loud noise upon startup

[Roger_Lucas]

Hi all...Just received my "new to me" '83 R65LS
Put it on the charger overnight, good to go. Checked oil...good!
Fired it up and WOW...thought a rod was coming through the case.Very noisy
Sounds to me like in the interm of it being shipped on a truck, etc. it somehow lost oil pressure.
Shut it down, restarted, shut it down, restarted...good.
Didn't let it run long in the process, thinking it needed to build up oil pressure.
Any thoughts?  It was ok starting up after that.
Thanks.

[montmil]

When the bike is shut down, oil pressure is lost; the engine does not maintain oil pressure unless the oil pump is operating.

Have you changed engine oil and filter to establish a maintenance baseline?

Have you checked valve lash? 0.004" intake and 0.008" exhaust.

Monte

[Roger_Lucas]

Monte...No and No.
The po just had carbs rebuilt and valves checked.
I am from now on going to assume nothing was done.
I started a list on what to get Friday. On it is oil, filter, etc.
Was worried when I at first heard the noise.

[nhmaf]

Maybe the bendix was sticking on the starter motor.  The starters are often forgotten about and they do need maintenance every 10 years or so.

[Rob Valdez 79 R65]

Don't ever trust a previous owner.  
Maybe if he is your best friend since childhood and he has been an airhead owner for 30 years.

Maybe.

Assume nothing has been done, and go over it with a fine tooth comb.

Such as:

• remove the rear wheel and check the final drive splines for wear and lube
• change all of the fluids
• drain the fuel tank completely and remove the petcock and make sure there is a screen covering the inlet tubes
• re-torque the heads and adjust the valves

and a thousand other things. (At least slide the gear box back and check out the input splines)

If it is a nice bike, you probably paid some money for it.  Isn't your investment worth it?

[Barry]

All engines start with no oil pressure but the oil light should go out very quickly. Depending on temperature maybe in less than 1 sec and with no great change in noise levels.

The only other thing I can think of that has not been mentioned is excessive compression in one cylinder due to oil or fuel in the cylinder. Was the noise accompanied by any smoke ?  

Even if the oil has obviously just been changed you might want to check the filter has the shim, O ring and gasket in the right order as this will result in low oil pressure if it's not been done right. No need to drain the oil to do this. You can lean it well over on the side stand and remove the filter cover for the loss of very little oil.

[Roger_Lucas]

Thanks all for your collective words of wisdom. I intend to do all of the above. I've owned one LS previously & a K75 that I also went through.
I have the clipboard and checklist on it, and ready to get started.
I just was not ready for the "noise" when I started it for the first time.
I am getting a list ready of things needed and heading over to Bob's BMW to get re acquainted with the parts department. Thanks again for thoughts and solutions.

[Bob_Roller]

I'm wondering if it was noise from the cam chain, with the first start up, the automatic cam chain tensionser, which uses oil pressure to push  a piece of rubber against the chain to take up the slack in the chain didn't have any oil, and the cam chain was slapping around until the tensioner finally got some pressurized oil  and quited things down .

[Roger_Lucas]

All things are possible and probably were.  Today, started fine.Soooo. probably a little of this and a little of that...cam chain possible...tipped on side and oil and gas in one jug also possible.....Anyhow, going to change oil, filter, drop pan(Old gasket looks ancient) clean strainer, etc.
Great forum guys, thanks again 8-)

[montmil]

OK, Scrat

Looks like you've now got a handle on it. Check everything. Trust but verify.

Be sure and start a maintenance log for everything that you do to the bike. The log will then become a valuable reference tool as you develop the bike into a reliable farm implement.

Monte

[Rob Valdez 79 R65]

Since you mentioned replacing the oil pan gasket, I will remind you again of the fragile threads in the block.
Don't overtighten these as it is easy to strip them.

The best tool for the job is one of these:



http://www.amazon.com/PALM-RATCHET-DRIVE-mechanics-4137com/dp/B000T6FB18

But since you have owned an airhead, you probably already know this.

And check & retighten them a few times for 500 miles or so after the installation, to catch any loosening fasteners.