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Fuel Filter or no fuel filter

Posted: Mon Aug 02, 2021 10:38 am
by Gossamer
Bikes been running good but on way home last Thursday lost power.

Wouldn't idle took a lot of throttle to get it moving.

Diagnosed it as no fuel to the right side cylinder.

Disassembled carb, cleaned out quite a bit of varnish residue. Did the left side as well, not quite as bad but still there.

So now that I'm running gas thru it and some cleaner(lucas or seafoam) since I knew there was residue I couldn't get out after it's 40 year slumber. I'm guessing the sloshing around and the cleaner is loosening up the residue.

So started thinking, should I get some inline fuel filters and put them in?

The R69 carbs are ridiculously simple to disassemble and clean out but would a filter help?

I would appreciate feedback from your experiences.

I have around 450 miles on it since the restoration. Had a few hiccups but otherwise really enjoying the bike.

Re: Fuel Filter or no fuel filter

Posted: Mon Aug 02, 2021 11:03 am
by schrader7032
I run filters from Vech on my R69S as well as my R25/2. Nice to see fuel flowing when I turn on the petcock. Not exactly easy to see them while riding. If you're concerned about fuel flow, you can measure ccs/min before and after to see if it's an issue. Duane discusses fuel flow and restrictions at the bottom of this page:

https://w6rec.com/bmw-petcocks-everbest-karcoma-germa/

Re: Fuel Filter or no fuel filter

Posted: Mon Aug 02, 2021 11:25 am
by jwonder
No fuel filters on the fuel lines but I run a filter in/on the petcock. There are many ideas here but no filters works for me.

Re: Fuel Filter or no fuel filter

Posted: Mon Aug 02, 2021 1:51 pm
by weh8127
Bing offers a brass tank screen that slips on over the petcock pipes inside the tank. That will keep out the big stuff and isn't so likely to impede fuel flow as in-line filters.

Bill Husted
Barre, MA

Re: Fuel Filter or no fuel filter

Posted: Mon Aug 02, 2021 5:06 pm
by Twocams
I have 6 motorcycles 1969 to 2018. They all have some kind of fuel filter. E10 (ethanol gas) is the worst & filters wont keep it "all" out. And ethanol collects water within 24 hrs? So I put some fuel additive in them cause I cant ride them all at same time, for some reason. :roll: Of course everyone does their own thing....right. :shock:

Re: Fuel Filter or no fuel filter

Posted: Mon Aug 02, 2021 7:58 pm
by jwonder
I wanted to be a bit more clear and follow up on my previous message.

I make sure I have a good, clean filter in the petcock and I clean it every time I change my oil. Knock on wood I have never had a clogged carb yet since I started to clean it at that interval.

These are the ones I am referring to for the /2’s.

https://bmwclassicmotorcycles.com/inde ... 6124084115

Re: Fuel Filter or no fuel filter

Posted: Wed Aug 04, 2021 2:44 am
by R68
Fuel filters are like prophylactics: some folks needs two, the one in the petcock AND a second in the fuel line hose. At my age, I only need one!