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304065 304065 is offline
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Join Date: Dec 2001
Posts: 9,549
I suppose a narrative update rather than just an itemized list of receipts would be fun.

I had a great time riding the bike to work in the summer and fall. The run from home to office is all of 12 minutes and parking not an issue on either end. Traffic was not bad although rush hour still rush hour.

The bike handles great and it's easy to negotiate the City. Even ran into some other airhead/oilhead owners on the street! The bike is a conversation piece which generates compliments even from random drivers at stop lights.

I took it out to Motorcycle Works in Brooklyn, to the owner Tom Pfeiffer, who has been in the business for 46 years. To say he has seen it all would be an understatement. After getting to know him a bit I found him to be an invaluable resource for all things airhead.

Turns out the fork seals were leaking oil onto the front brakes so the bike would not pass inspection. I scheduled a service appointment for those-- while not particularly complicated, the thought of pulling off the front wheel in the street in late fall just did not appeal to me. So it was out to Tom's shop in Brooklyn for the work.

Tom also went through the bike and came up with a list of other items to do, the inevitable issues that present when a bike sits for a long time. The clutch cable was from another bike entirely, and wasn't adjusted right. Turns out that airheads have an easy clutch, I thought it took an Iron Hand to operate these bikes, wrong! Once he put the new cable on and adjusted it right the clutch was smooth and easy to operate.

He also synchronized the carbs and adjusted the idle to perfection. It now idles at 900 rpm like the Factory says it should.

There are a few other things to fix- the swing arm boot is cracked and needs to be replaced at the time of the next spline lube.

The biggest thing Tom found was wear to the timing chain. About five minutes after startup once the oil warms, you can hear a very distinctive metallic tapping that is the timing chain flopping around.

The '81 has a simplex, single-row chain and hydraulic tensioner which is not that complicated compared to the chain tensioning system on a later 911. Actually there is an oil feed to the piston that pushes on the tensioner rail, and that oil spills out of the tensioner to lubricate the chain.

I decided to pull it apart to take a look. The first thing I realized is that after you get the front engine cover off, you're looking at the alternator rotor and stator and the ITU ("Bean Can") below. You remove the stator then pull the rotor with the special hardened rotor-pulling bolt, it fits on the nose of the camshaft with a tapered fit, then the intermediate housing will come off.

Except in my case the front exhaust crossover pipe was in the way. Went to take it off and it was rusted in place, the clamp on one end was missing entirely and the other one encrusted in rust. I wasn't about to remove the exhaust nuts to remove the crossover pipe, as these are likely frozen in place and will need to be carefully cut off with a grinder to avoid damaging the threads in the heads. So I just cut the crossover tube with a grinding wheel and was free. It had to be replaced anyway.

Once that was clear I could get the intermediate housing off to expose the timing chain. I disassembled the tensioner by removing the e-clip at the top, there was a LOT of slop in the chain.

So I'm going to order the parts this winter and fix this up right. I will change the crank sprocket at the same time. Probably going to leave the cam sprocket alone and resist the temptation to install a Siebenrock cam and lighter cam sprocket, if only because the R65's lifters are a hollow type, the pushrod actually goes INTO the lifter and touches on the inboard end to accomodate the narrower motor- and the lifters are NLA as far as I can see. So will leave that for a later project.

When Tom was tuning the carbs, he noticed that the idle jets did not have any O-Rings! The carbs are due for an overhaul, when I drained the float bowls for winter storage there was accumulated crud, not loose, but these will be vapor blasted.

Will post an update when that work begins.

'66 911 #304065 Irischgruen
'81 R65
Ex-'71 911 PCA C-Stock Club Racer #806 (Sold 5/15/13)
Ex-'88 Carrera (Sold 3/29/02)
Ex-'91 Carrera 2 Cabriolet (Sold 8/20/04)
Ex-'89 944 Turbo S (Sold 8/21/20)

Last edited by 304065; 12-23-2020 at 05:59 AM..
Old 12-23-2020, 05:42 AM
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