Starting your bike after a few days layoff!!

[MrRiden]

The clear fuel filters will almost always show an air bubble on initial installation. A few taps with your fingers on the filter should dislodge any bubbles. They may reappear but you should not see the filter go completely dry. Bob and Ed previously mentioned the enriching circuit in the carb. Check your float bowls, the enricher fuel pickup jet and the bowl gasket itself. also have a look at this thread: http://www.bmwr65.org/cgi-bin/yabb2/YaBB.pl?num=1240083062
rich

[nhmaf]

That "hole" under the tank is not a vent - it is to direct the overflow if the tank is overfilled..   Many people remove the hose that was there initially as it is another nusiance to deal with when removing the fuel tank, but if you ever overfill your tank or fuel sloshes up there in the indentation around the cap you'll be squirting gasoline down on the engine and into the starter cover area - not generally advisable.   IF you don't put a hose back on that "hole under the tank", be careful about filling your tank and stop at the bottom of the "neck" in the fill hole.    Otherwise, get some clear fuel line hose and stick it onto that short pipe under the front of the tank and run the hose back toward the battery box and then down the frame tube so any excess gasoline is spilt behind the hot and electrical bits (and preferably to the side of the rear tire).

 

The venting of the fuel tank actually happens through the filler cap.
Sometimes they do plug up as they rely on small holes at the base for the cap for air/fuel vapors to go up in the cap and escape either through the key slot or an area under the top plastic cap part.  

[Justin B.]

Cleaning the "screen" in the tank should be a semi-routine maintenance procedure .  As these tanks get older the factory lining tends to flake off and clog up the screen...

[beemer]

Cleaning the "screen" in the tank should be a semi-routine maintenance procedure .  As these tanks get older the factory lining tends to flake off and clog up the screen...

Luckily i didn't find any debris in the tank,but i have also done the tank cap mod and the flow is much stronger now,also checked the enrichment system in the bowls and all clear,so hopefully all should be ok.

[R65_Mark]

I had the gas tank off my ’84/5 R65 today and happened to measure the overflow drain outlet boss on the underside.  It is 8.0 mm (5/16-in) diameter.  Like montmil above and others, I fabricated a drain pipe from 5/16” fuel line to discharge near the rear tire to take any future overflow away from the electrics and hot spots around the engine.  Peace of mind.

Here's the fitting I used:

McMaster Carr
Black nylon single-barbed 90° elbow tube fitting
Inside tube diameter 5/16"
Part No. 5463K17
Approx. $6 for 10 before trade discounts

Mark