The New And Improved Unofficial R65 Forum V2
Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: Bob_Roller on June 27, 2007, 07:09:51 PM
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I reinstalled both carbs today, along with replacing the fuel lines and fuel filter. There's been discussions about how fuel filters restrict fuel flow, and possibly cause problems at highway speeds. I was going to drain the fuel tank and remove the petcock for cleaning, so I decided to check the flow rates for no fuel filter, and fuel filter installed. The results that I got were : no fuel filter petcock ON: 7.8 gallons per hour, no fuel filter petcock on Reserve: 13.6 gallons per hour, fuel filter petcock in ON: 7.4 gallons per hour, fuel filter petcock on Reserve : 12 gallons per hour. I figure at legal highway speeds here in Arizona (75 mph) that I'm probably at 1.8-2 gallons per hour fuel consumption. So it doesn't look like the fuel filter is going to cause any problems for me at least. I am using a common clear plastic filter with a sintered filtering element. I also tested an old filter with 3 years on it, and the results were within 5% of a new filter. Yeah , I was really bored today, but somebody has to do the testing to blow the generally accepted myths away ! Also, after draining the tank with the petcock on reserve, I got 60 ounces of fuel out of the tank with the petcock removed, so there is a little under a half gallon US of 'unuseable' fuel left in the tank when reserve is depleted.
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Bob,
I admire your thoroughness. Good to know that the filter will flow several times the engine requirement when maintained. I did at one point have a fuel starvation problem, that turned out to be improperly set floats. I'm still not comfortable with the plastic filters tho. Now for your next quest: What is the average airspeed of an African swallow? :)
rich
who has cut his reserve tube flush
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Good work, Bob. I would send you a Mars bar in the mail, but I'm afraid it would be a molten mass by the time you received it. You probably have to eat your chocolate fast there, don't you?
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Yeah Rob, chocolate lives a hard life here in the northern Sonoran desert in June, the half life of ice today is about 45 seconds. It's only 109 F. at 5 :45 pm, wait till next Tuesday, it's forecast to be 115-117 F., but there's always the relief, that it will be a dry heat!
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Rich, average speed of an unladen african swallow is about 24 mph.
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Kudos to you, Bob, for having the patience and scientific method to
do this experiment. I've been told, and have theorized that there
was probably a quart of gas trapped on the far side of the tank
after reserve. your test indicates that there can be even more over there -
so, if one is running low, has hit reserve and still no gas station in sight,
it IS beneficial to stop, tip the bike onto the petcock side, and free up those
precious ounces of go-juice.
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Bob, great test and it proves to me that my gut feeling about "clean" fuel filters severely slowing down fuel-flow was way overblown. If you want to stir up a hornets nest post your testing results on boxerworks, I'm sure Ausherman and cabal will waste no time giving you a good hiding...
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Justin, I already posted over here, just waiting for the incoming rounds!
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He, he, he... Put on yer Nomex(r) drawers, buckaroo, gonna git powerfully warm whar yer goin'! [smiley=flamethrowingsmiley.gif]
You already have two responses...
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Even though I'll probably never put one on my bike, I applaud Bob's work so that those that do want to use them, do not have to worry about interferance. At least, not with that particular brand... ( ;) )
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Yeah Rob, chocolate lives a hard life here in the northern Sonoran desert in June, the half life of ice today is about 45 seconds. It's only 109 F. at 5 :45 pm, wait till next Tuesday, it's forecast to be 115-117 F., but there's always the relief, that it will be a dry heat!
i have felt that dry heat! it doesnt matter! still feels like your in a oven. hot is hot no matter how you say it.
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It makes a difference Jon. Baking is better than stewing, though neither are good options.
I use the filter that Snowbum recommended on his web site.
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Well, Bob, your boxerworks thread has remained fairly sedate. The only person you seem to have "poked with the proverbial stick" is Munger. He seems to think you are purpoxely dodging his questions. I am sure he is trying to bait you in one direction or another so he can pounce...
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Like a cat...playing with a mouse...!
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Yeah, I'm getting to the point where I only check boxerworks threads a couple times per week and rarely reply anymore. I have came to the conclusion that if I have a question I'm better off researching and going by my gut feelings than posting a question over there and then having to wade through several days of smart-ass replies, etc.
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The reason I havn't responded to my post, is that I lost inter-net access last Thursday evening, and Cox Communications is telling me it may be up to 4 weeks before I get it back, also don't have telephone service or cable television service. Looks like a construction job went terribly bad, I lost electrical power at the same time for 22 hours. One good thing, the refrigerator and freezer got cleaned out like it never has before. I'm at work, and I finally was able to log in today on this site, but Boxerworks comes up as restricted site category : Tasteless ! I have to admit I too have grown weary of the antics on Boxerworks, and I think that unless I have no other choice, fuel filters was my last post there.
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The Airlist is the place for nearly pure tech stuff.
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Bob, hope you get your internet issues straightened out and maybe you can lobby for a few months of free service for your troubles. I know I have done that with other ISPs.
I don't think any of the lists are very "tolerant", I also subscribe to the list put out by ibmwr.org and a lot of personality conflicts, sniping, and nit-picking... The older I get the less tolerant of this type of crap I become - well, less tolerant in general. That is one of the main reasons I quit the computer service/support biz after over 25 years and decided to totally switch career paths. ::) Although being a machinist is a lot more physically demanding I only have myself to blame if I make a boo-boo and I don't have to answer whiny-ass questions from bone-heads.
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Justin, I've been an aircraft mechanic on commercial type aircraft for about 31 years, so I know a bit about turning a wrench, and even with minimal maintenance manual help, I've done a decent job of maintaining my R65 for the last 26 years, and 80,000 miles. But it's nice to have access to 'real world' problems that defy anything described in the available manuals on the R65, but like you said the 'antics ' have become intolerable to me. It seems that since I turned 50 last August, my bull**** tolerance has evaporated like ice on Phoenix Fourth of July afternoon !
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Every bike I have has inline fuel filters. I have not had a fuel stavation problem due to a filter yet. Usually it is because I decided to stretch the reserve too far. :-[
TTFN,
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Bill, this is the first fuel filter that I have installed on a bike, I thought that the petcock stand pipe on my R65 had a metal screen, but I am wrong, at least on my bike. Every time I removed the carb float bowls, I always found a fair amount of fine grit and a couple of globs of water as well. I've had this filter on the bike for about three years, and I found no grit or water this time, and it has been three years since the float bowls were last removed and cleaned. So I guess that the filter did it's job. I did a search of the Visu-filter web-site,and they have a high flow filter, with about 15 times the filter surface area of the sintered element filter that I have now. Cost is about $3, only down side is you have to order them, and shipping costs about as much as the filter itself.
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Start up a "group purchase", maybe even get price break on quantity and everybody shares in the shipping...
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Bob
I have used the small plastic inline filters on my bikes since around 1984 and have not felt I had a fuel problem with them. The only time I have had a fuel flow problem was when I put stabil in the tank and the coating came loose and block the petcock. Your post a couple back could have been me posting. I have been and A&P since 1977, starter in school for this in 1975. Have stayed in General Aviation working on small singles to Beech King Air's and contract work the Major airlines that come to Monroe. Still have my first BMW 1982 R65 plus a 75 R90/6 with a RS fairing installed and a 1980 R65. I would have been nice if this Forum was avaible back then. I was lucky that I had a good friend that had a small motorcyle shop started a BMW dealership in 1984 - 1989. When he sold out and the new owners drop the BMW line I was able to get the shop tools.
Don
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Don, that's really cool to be able to "fall into" a cache of Airhead tools!