The New And Improved Unofficial R65 Forum V2

Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: BooG on June 27, 2016, 01:18:01 PM

Title: Fuel filter
Post by: BooG on June 27, 2016, 01:18:01 PM
I am about to install an in-line fuel filter after having cleaned out the gas tank. I am assuming I can install just one filter in the hose out of the petcock,(before the splitter), to serve both carbs, or do people install one filter for each carb?
Thanks.
Title: Re: Fuel filter
Post by: Oconner on June 27, 2016, 01:24:47 PM
yep that's where mine is.
Title: Re: Fuel filter
Post by: SoloLobo on June 27, 2016, 01:47:23 PM
No need, as there should be a filter on the intake for the petcock
Title: Re: Fuel filter
Post by: BooG on June 27, 2016, 02:51:09 PM
There is indeed a new mesh filter on the petcock inside the tank. Advice seems to be to install a paper filter as well, rather than another mesh one, which would be doing the same job as the in-tank one.
Title: Re: Fuel filter
Post by: Bob_Roller on June 27, 2016, 03:17:19 PM
I installed a paper filter in the line between the fuel tap and splitter .

Before I did this, when ever I removed the float bowls, I always had fine gritty sediment and a few globs of water in the carb bowls, since using the extra filter, this hasn't returned .

Also something that gets overlooked, is the rubber gasket on the fuel cap .

If the gasket is bad, it can allow water into the fuel tank, as it collects there until there is enough to go out the drain for the area .

Not a bad idea to check the drain to make sure it's not clogged .
Title: Re: Fuel filter
Post by: montmil on June 27, 2016, 04:48:35 PM
Quote
No need, as there should be a filter on the intake for the petcock

In-tank filters over the petcock straws. So why do I find the occasional grungy bit in my inline filter? Several owners have removed their petcock/s to discover there's no mesh filter to be found.

I use the tapered, conical filter with a ceramic insert on all three of my Airheads. Lawn mower shop style. Never a problem with grit screwing with the float needle and creating a drippy mess. Cheap insurance.
Title: Re: Fuel filter
Post by: nhmaf on June 27, 2016, 07:56:47 PM
The key thing is for the filter to have high enough flow rate to not impede the filling of the carbs under situations with wide throttle openings.  If the filter is too small, it might not flow fast enough - so just be aware of that when shopping.
Title: Re: Fuel filter
Post by: thrang on June 28, 2016, 03:40:05 AM
Before I replaced the fuel tap and sealed the inside of the tank I always ran a disposable in-line filter between the tap and splitter. I never ran into flow problems but I did make sure to replaced the filter every 5000 miles.  
Title: Re: Fuel filter
Post by: montmil on June 28, 2016, 08:17:38 AM
 [smiley=whistling.gif]
Quote
The key thing is for the filter to have high enough flow rate to not impede the filling of the carbs under situations with wide throttle openings.  If the filter is too small, it might not flow fast enough - so just be aware of that when shopping.

The single small, ceramic-core fuel filter feeding both Bings allows my R65 to exceed The Ton. Fuel flow does not appear to be insufficient.   ::)
Title: Re: Fuel filter
Post by: Tony Smith on June 30, 2016, 01:25:10 AM
Quote
The key thing is for the filter to have high enough flow rate to not impede the filling of the carbs under situations with wide throttle openings.  If the filter is too small, it might not flow fast enough - so just be aware of that when shopping.

Exactly what happened to me when I thought I'd be clever and use a lawnmower shop sourced disposable filter.
 
I now rely totally on the in tank mesh filter, yes it does let stuff through, but nothing big enough to clog a jet.
Title: Re: Fuel filter
Post by: wilcom on June 30, 2016, 09:47:45 PM
Quote
The key thing is for the filter to have high enough flow rate to not impede the filling of the carbs under situations with wide throttle openings

I was always pretty bad about running with 1 petcock open and I ran into a situation where my R80 (1982RT) would starve for fuel unless I opened both, (head wind and run'n hard.


 I thought it just wouldn't feed enough with just one open but it sure could have been those TA filters. I have used those small cone shaped filters for ever.

The R80 was the most thirsty of any Beemer I have owned, wouldn't crack the high 30's  normal riding and run'n hard it would drop into the mid  20's     :-[............... Makes the 50+ mpg of the R65 feel like a modern ecomobile  :D
Title: Re: Fuel filter
Post by: Luca on June 30, 2016, 10:43:17 PM
I use a John Deere AM116304 sourced from the parts room at work.  Actually, it's an aftermarket replacement for the JD filter.  Flows plenty fine.  The only problem I've ever had with in-line filters is sometimes they get airbound and won't flow fuel using gravity alone.  When that happens I can usually fix it by flicking/shaking the filter.
Title: Re: Fuel filter
Post by: Warbucks on July 03, 2016, 07:01:49 AM
When I restored my tank the mesh filter was rotted out and I did not bother to replace it. That is possibly why I do not have reserve at the petcock. I'm not sure about that, but it's of no concern to me.

I installed an aftermarket fuel filter (recommended for a 6 cylinder car engine) between the petcock and the T junction before the fuel enters the Bings. As you can imagine, the filter is quite large and very noticeable. In saying that, it does the job nicely and I no longer care what it looks like.

That's just the kind of guy I am.  [smiley=beerchug.gif]
Title: Re: Fuel filter
Post by: badgertom on July 03, 2016, 04:45:04 PM
I installed a "see through" pastic filter so that I can monitor flow to the carbs. If there is an engine problem I can easily rule out flow to the engine.