Choke Cable Length Question & Fuel Line Notes

[R65_Mark]

One carb choke cable question and some notes on fuel line things I learned doing a quick clean up last week.

Question - CHOKE CABLES
My choke cables seem a little long.  Here’s a picture of the routing on one side (the other is similar.)  They seem to loop back rather than be a gentle sweep forward.  Is this unusual?

IN-LINE FUEL FILTER & FUEL LINES
I wanted a paper filter to replace the in-line mesh filter (which had a courser mesh than the in-tank filter and was doing nothing) fitted by the previous owner.  The common references point to NAPA SME 702323 and 3011 and the FRAM G4164 filters.  However, as they are designed for a universal fit for 5/16 and 1/4” lines, they are longer than I really wanted.  The NAPA SME702323 is a “small engine” filter, so I went through other small engine references and came up with the Briggs & Stratton 691035 (some references have its part number as 491629).  It’s a 60-micon filter with 1/4” single-barbed connection bosses and is only 70mm/1.75” overall length (the NAPA etc are about 100mm/4”) and on the shelf at Lowes and Home Depot.

I replaced the fuel lines with 1/4” GATES XL SAE 30R7.  Even managed to get this to pass through the air box without much problem (silicone spray on the hose, a welding rod as a guide and pushed the line through the air box opening until I could grab it with needle-nosed pliers on the other side).  There is a big difference in OD.  The original BMW hose measures 10.7mm (0.42”) whereas the Gates replacement measures 12.6mm (0.50”).  Hardest part of the job was getting the old lines off at the carbs.  I assembled everything using spring clips

Doing the work took less time than tracking down the filter, less than one hour start to finish

Mark

[Justin B.]

I don't think you'll need the clamps, but they won't hurt.  Your next chore should be to loose the Fresh Air System!

[R65_Mark]

Justin, you’re right about the clamps, but I had a whole bunch to hand (I’ve used the spring clips for years on the fuel systems of my Triumph cars as an alternative to worm drive/Jubilee hose clips – and converted many users of the latter to the former).  I first started using spring clips as just enough of a deterrent to thwart the, typically drunken after-hours, antics of those that seemed to think there was nothing funnier than pulling the fuel lines off of ‘bikes parked in public places.

Mark

[R65_Mark]

I'm bumping this up to nudge a response to my question about choke cable lengths.  I checked out some R80 and R100 airheads that I passed by parked up in the street last week and all three had throttle and choke cables that ran forward from the carbs rather than looping back a little before going forward like mine can be seen to do in the picture above.  

What's the routing look like on others' R65s?

Is there a magic parts table look-up that will give different cable lengths I might try?

Thanks.  Mark

[nhmaf]

What do you have for handlebars on that bike?

It is possible that you might have the US bar's cables but using lower Euro style bars?

Do your cables use a "splitter" .i.e.   there is only (1) cable that comes out of the throttle assembly or (1) Cable out of the choke lever housing, or are there (2) cables coming out of those?  If only (1) cable out of each, then you've got the 'splitter; type cable.  It might be possible to use shorter "lower" end cables (which go from the splitter(s) to either carb for throttle and choke, but these are in only a couple lengths, I believe...

[Bob_Roller]

There are a few different length cables, for standard bars and high bars .

I don't know if you you about RealOEM.com, but it's a valuable, parts catalog .

You need the last 7 digits of your bikes VIN, a place that in to the search box on the second page .


 � http://www.RealOEM.com/

[montmil]

This is a good opportunity to share an enrichener / choke control observation...

1978 R100S pal at work has very neat, short and well-crafted hard wires (stainless, I think) that extend only 2-3 inches above the Bing tops. No adjustment or cable splitter needed. They pass thru the threaded adjuster bits.

It is a bit humorous watching him ride off, then reach down and push each of the button-topped wires to close the enrichener system.

Does clean up the carb area and eliminates a handlebar control lever and cable assembly.

Round these parts, the enrichener usually comes off about the time my helmet chin strap gets buckled and I'm ready to roll off.

Monte

[R65_Mark]

I do have low ‘bars, and seems like whenever these were added the high ‘bar length cables were retained.  My accelerator and choke set ups are both single cable to splitter and then two cables form the splitter to the carbs.

The parts schedules on RealOEM for my late ’84 R65 yield this information.

For the accelerator, there are two lengths listed for the splitter to the carbs section, one 487mm the other 382mm (the ‘bars to splitter is listed at 770mm).

For the choke, there are two lengths listed for the ‘bars to splitter section, one 764mm the other 544mm (the splitter to carbs is listed at 564mm).

Also digging around on RealOEM for R80/R100 models from the same vintage shows up various other cable lengths options that I’m going to assume are probably interchangeable.  Is this correct?  Does anyone have any experience to offer swapping out these for different lengths to offer?

I’ll take the gas tank off when doing general maintenance this weekend and measure up what I have, make a judgment on what might be better, and report back here with my findings.

Mark

[Ed Miller]

This is a good opportunity to share an enrichener / choke control observation...

1978 R100S pal at work has very neat, short and well-crafted hard wires (stainless, I think) that extend only 2-3 inches above the Bing tops. No adjustment or cable splitter needed. They pass thru the threaded adjuster bits.

It is a bit humorous watching him ride off, then reach down and push each of the button-topped wires to close the enrichener system.

Monte

I like it.  Simpler by choice!

[R65_Mark]

I finally have sets of the correct length throttle and choke cables for my R65.  These are about 4-inches shorter than those on the ‘bike at present.  Is there a trick to setting up the correct routing, or is it just obvious?  It would be a big help if anyone has a picture or two to show how they are routed around the head stock and under the tank.  Thanks.  Mark

[montmil]

... It would be a big help if anyone has a picture or two to show how they are routed around the head stock and under the tank.  Thanks.  Mark

Don't we all wish! Wise folk photo document cable runs before removing them for service or replacement... that's good if they have never been messed with by multiple PO's. Wishful thinking. Some owners run a string along the cable's pathway. Good idea, too.

Otherwise, you will need to install the cables -carb and/or enrichener- is such a way as they do not bind when the forks are turned to their stops in both directions. I have heard some say they it is not a good idea to zip-tie the cables tight to the frame tubes or elsewhere. I know this happened to me and the problem went away after loosening the cable run guides.

Perhaps someone will post a photo or two. When you get yours run satisfactorily, post pics for us! Good luck. Keep the kill switch handy.

Monte

[R65_Mark]

I'll certainly post pictures if I get something that works well.

Also, anyone have tips on how/what to lubricate?  I seem to remember reading somewhere that the cables have nylon cores and, as such, lubrication in not needed/desired - true or false?  Further, what's the consensus on oil/grease for the splitter/adjuster cylinder/piston   mechanisms?  Thanks, again.  Mark

[Bob_Roller]

I have cleaned and lubed the throttle and 'choke' cables, even though I've been told it will ruin them .

I remove the cables from the bike, take a 'fold and close' sandwich bag, and cut one corner out of bottom, insert the cable into the bag, wrap the bag around the cable, and then secure with a ty-wrap .

I then tape the plastic bag to a work table and then place a drip pan under the cables .

To clean the cables, I put an ounce or two of isopropyl alcohol into the bag, and then move the cable up and down to get the liquid moving down the cable, repeat until the alcohol comes out clean .

To lube the cable, I put a cable lube, or light oil in the bag, and then move the cable to get the oil moving down the cable, then just wait until all the oil flowed down the cable .

This method also works on the clutch cable, and the speedometer drive cable , only difference with the speedometer cable, is I put the cable end into a cordless drillmotor, and rotate the cable while adding the alcohol to clean it .

In my opinion, you don't need any grease or oil in the splitter cavity, as the plastic part that the cables attach to, doesn't touch anything in there, and it just makes it a bit more work to clean it up when you do open it up .

[Barry]

I recently re-routed my throttle cables so that they ended up perpendicular to the the Carb adjuster. Previously the LH cable had been routed so that it seemed too long at the carb end.  It  turned back on its self a little which put a strain on the cable as it entered the adjuster.  I just experimented with the routes to get the best fit at the carb end.

I also used some heat shrink tube to support the outer cable. Not a new idea by any means. Works well though.