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Thread: Two different R27 problems!

  1. #1

    Two different R27 problems!

    Hi,

    After many years of wanting one (mostly emotional, certainly not logical!) I purchased a 1966 R27 this summer. Lot's of fun and brings me back to simpler times. When I first got it the top speed was about 50. After plugging some air leaks in the fuel system, running carb cleaner, new spark plug wires and adjusting the carb that is up to about 70.

    Two problems that have me a little unsure:

    - when the bike is cold and I adjust the idle stop in idles nicely, but when hot the idle is up around 4000 rpm. I can adjust the idle back down and it runs smoothly, but it means that I'm constantly adjusting the idle stop with engine temperature.

    - while riding down the freeway last night the red light came on. Over the next 15 miles home the lights got dimmer and dimmer and were barely lit for the last 5 miles. The bike ran fine otherwise. I've been having to add water to the battery most every time I ride it. Perhaps the voltage regulator or coil?

    Thanks for any tips!

    All the best,
    Paul

  2. #2
    Liaison 20774's Avatar
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    Paul -

    Welcome! Good speeds on that R27. I've been seeing speeds of 90 on my R25/2...ummmm, 90 kph that is!!

    As for the carb issue, you might want to look at the advance unit...it may be sticking open. Plus, you might have the carb slide sticking as well. Sounds to me like you might need to overhaul the carb. Have you done that with this bike?

    RE: generator light, the brushes might be hanging up and/or are too short. Take a look at them. There's a small spring that is supposed to push them down against the commutator. RatShack makes a spray that is good for electrical circuits. It's a cleaner and lubricant...might be worth a try.
    Kurt -- Forum Liaison ---> Resources and Links Thread <---
    '78 R100/7 & '69 R69S & '52 R25/2
    mine-ineye-deatheah-pielayah-jooa-kalayus. oolah-minane-hay-meeriah-kal-oyus-algay-a-thaykin', buddy!

  3. #3
    James.A
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    1) regarding the idle.
    Make sure there are no vaccum leaks anywhere on the Carburetor or the intake downstream from the carb. Pay particular attention to the top of the carb where the throttle cable goes in. There is a small o-ring under the threaded collar that holds the top together. Next, make sure that your centrifugal advance it proprerly functioning. When I did mine, I lubricated the pivot points and installed new springs. When you have eliminated vacuum leaks and confirmed the function of the advance mechanism, you will want to adjust for a desireable warm idle, and then LIVE WITH THAT. It's an antique machine. There is no choke or enricher to compensate The air fuel mixture for cold operation. This was one of the hardest things to accept when I was campaigning one. I learned to let the dang thing warm up a little before a took off, manipulating the throttle to keep it running until it stabilized. Also I had retro-fitted a type 53 carb from an r50/5. That carb has an accelerator pump in the main jet stack. I later discovered that my R27 had a carburetor originally fitted to an R26 on it when I brought it home. The type 53 carb solved all my fuel mixture issues.

    2) electrical issue.
    The red light indicates a charging failure. This seems at odds with your need to replenish the battery acid. That is always an indication of over charging and a malfunctioning voltage regulator. If your battery is not fully charged, the light can glow at low idle speed because the generator it'self is not producing the minimun out put to activate the regulator. If your light came on at highway speed, that suggests an abrupt change of the function of the voltage regulator to me.
    These things can be taken apart and contacts cleaned. If you had a service manual you could test for continuity of the windings.

    I no longer have mine, having sold it with the bike last year.
    Last edited by woodnsteel; 11-20-2010 at 10:49 AM. Reason: spelling

  4. #4
    Thanks Guys, very good ideas! The carb air leaks were (are?) an issue, exactly as described and I plan to rebuild this winter. Today I found a crack in the expansion joint just in front of the carb, so that is another thing to replace...

    Each little fix is noticeable, so I'm having fun!

    Cheers,
    Paul

  5. #5

    simple tests

    1. Get a spray bottle of gas and spray it around carb to see if engine idle increases due to sucking in gas/ identify any air leaks. Be careful to not get to much sprayed around to avoid fires.

    2. use a DVM ( Digital Volt Meter) to check battery voltage with bike not running should be around 12.8V. Then start Bike and check voltage at idle and at higer RPM to see if there is higher voltage/ battery is chargeing.

    1974 R75/6 W Sidecar
    1989 R100GS


  6. #6
    Cannonball Rider #52 darrylri's Avatar
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    Quote Originally Posted by 85K100LT View Post
    1. Get a spray bottle of gas and spray it around carb to see if engine idle increases due to sucking in gas/ identify any air leaks. Be careful to not get to much sprayed around to avoid fires.

    2. use a DVM ( Digital Volt Meter) to check battery voltage with bike not running should be around 12.8V. Then start Bike and check voltage at idle and at higer RPM to see if there is higher voltage/ battery is chargeing.

    Don't spray gas around the running bike, it's very dangerous. Use WD-40 or something like that.

    These bikes are 6V not 12V. You should see something like 6.6V when the battery is charging (well above idle).
    --Darryl Richman, forum liaison
    http://darryl.crafty-fox.com

  7. #7
    Rally Rat 1074's Avatar
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    Quote Originally Posted by millerph View Post
    Hi,

    After many years of wanting one (mostly emotional, certainly not logical!) I purchased a 1966 R27 this summer. Lot's of fun and brings me back to simpler times. When I first got it the top speed was about 50. After plugging some air leaks in the fuel system, running carb cleaner, new spark plug wires and adjusting the carb that is up to about 70.

    Two problems that have me a little unsure:

    - when the bike is cold and I adjust the idle stop in idles nicely, but when hot the idle is up around 4000 rpm. I can adjust the idle back down and it runs smoothly, but it means that I'm constantly adjusting the idle stop with engine temperature.

    - while riding down the freeway last night the red light came on. Over the next 15 miles home the lights got dimmer and dimmer and were barely lit for the last 5 miles. The bike ran fine otherwise. I've been having to add water to the battery most every time I ride it. Perhaps the voltage regulator or coil?

    Thanks for any tips!

    All the best,
    Paul
    The idle, mixture ans speed, should be adjusted on a warm engine.
    Definitely a charging problem. Always start your troubleshooting with a good, fully charged battery. Measure voltage across the battery. Start the engine and rev it up while measuring the voltage. It should climb. Check it with the lights on high beam as well. If it goes over 7.5 or 8 volts, then it's most likely the voltage regulator. these bikes are not known for their superior lighting.
    Boxerbruce

  8. #8
    Hi,

    A follow up to my earlier posts. I ordered the carb rebuild kit from Bing and spent a couple evenings taking it apart, soaking it, cleaning it and putting it back together. Only one extra part!! It is some sort of rubber cable cover but doesn't show up on any of the diagrams or pictures of the bike so I'm not too worried.

    I greased the advance, put the carb back on, wrestled the tank on (why it doesn't fit around the seat will be another issue to solve) and the bike jumped to life on the third kick and is running great. I had an enjoyable 30 minute ride around the neighborhood today. There were a few weeps that I had to tighten some of the smaller machine screws to eliminate, but it looks like the fuel system woes are at least temporarily solved.

    So, now back to the charging issue. The red light stays on and no voltage increase is seen at the battery. Unlike what the shop manual says, if I pull the ground off the battery when over 2500 rpm, the bike stops. The new Rhino SLA 6V 9AH battery has all the lights going brightly. I checked all the grounds I could find for looseness or corrosion. I cleaned the brushes and made sure the springs are holding them tight against the commutator. They are about 5/8" long. I replaced the voltage regulator. I've ordered a new condenser.

    I tried repolarizing. No luck with the red light issue, but I did get a spark, which I think was a good sign. In a fit of cleaning frenzy I took some cleaner and wiped down the commutator. The rag came away quite black and now instead of a bright red light, at higher rpm the light dims just a bit.

    So, the advice given on the carbs was spot on, what is a good next thing to try on the charging?!

    Cheers,
    Paul

  9. #9
    Liaison 20774's Avatar
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    Since the R27 is a battery-coil ignition system, you can't pull the ground for the battery and expect it to run. A good battery and ground is needed. The magneto systems (R60/2, R69S) don't need a battery to run.

    Condensor won't have any effect on the charging...it's part of the ignition system.

    I reread your first post, and it sounds like the charger was working initially but then the red light came on. That means that the wiring was OK at some point.

    Something must gone bad in the wiring. If the regulator is new, then that can't be it. Maybe you've lost the commuator...IIRC the various contacts are interconnected by all the wiring. Possibly some part of the wiring has shorted or gone open.

    I think you're going to have to do some tracing of the wiring. That's going to require a good wiring diagram. Vech at Bench Mark Works sells a book by Doug Rinckes that provides a lot of detail and troubleshooting tips.
    Last edited by 20774; 02-13-2011 at 01:47 AM.
    Kurt -- Forum Liaison ---> Resources and Links Thread <---
    '78 R100/7 & '69 R69S & '52 R25/2
    mine-ineye-deatheah-pielayah-jooa-kalayus. oolah-minane-hay-meeriah-kal-oyus-algay-a-thaykin', buddy!

  10. #10
    BTW, my tank doesn't clear the seat either.
    '13 690 Duke, '13 Daytona 675R, '18 Street Triple RS, 2020 R1250R, '19 Ninja 400 (track bike), '21 Duke 890R (gone but not forgotten: '61 Clubman's Gold Star, '76 R75/6, '84 R100, '76 R90S)

  11. #11
    Liaison 20774's Avatar
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    If the charge light burns bright all the time, it looks like the regulator is not functioning properly or is not adjusted correctly. What type of replacement regulator did you use? I understand that a solid state regulator is probably the way to go.

    On my R25/2, I have to undo the seat spring to pull the front of the seat back a bit. Then, with some coaxing, the tank will come off.
    Kurt -- Forum Liaison ---> Resources and Links Thread <---
    '78 R100/7 & '69 R69S & '52 R25/2
    mine-ineye-deatheah-pielayah-jooa-kalayus. oolah-minane-hay-meeriah-kal-oyus-algay-a-thaykin', buddy!

  12. #12
    Hi,

    Yes, it was very sudden when it stopped working. I was riding down I-97 at about 7 o'clock at night (in the fast lane with commute traffic) when suddenly the charge light came on. The lights immediately basically went out. That was kind of exciting.

    I was checking the wiring and leads this morning. I don't know if it is significant, but if I put a voltmeter from the "9 o'clock" brush and rev it up I get about 1.7 V to the blue wire. From the "12o'clock" brush I get about 0.6 V.
    http://www.flickr.com/photos/roundel...7594434937833/

    My commutator is very black around the path the brushes travel vs the clean copper in the picture. Perhaps a thorough cleaning of the commutator...

    The regulator I put in is a mechanical Bosch, new construction but looks just like the old ones. The electronic one available from Bob's was definitely not a plug and play and I didn't want to fool around with that.

    As I understand it the regulator is supposed to open to allow the current through when the voltage from the generator gets to 6.5V-6.8V plus. The blue wire is the one going to the regulator from the generator and since I'm only getting 1.7V, the regulator will not switch on to let the current to the battery. That is, if the generator puts out 6-8 V instead of a different value with a stepper.

    According to the shop manual the bike should run with the battery ground lead disconnected if the generator is putting out a high enough voltage for the regulator to open. The wiring diagram shows that the circuit is then open from the generator to the coil.

    Cheers,
    Paul

  13. #13
    Liaison 20774's Avatar
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    Quote Originally Posted by millerph View Post
    According to the shop manual the bike should run with the battery ground lead disconnected if the generator is putting out a high enough voltage for the regulator to open. The wiring diagram shows that the circuit is then open from the generator to the coil.
    Paul -

    That is news to me. It is my understanding that a battery-coil ignition system must have the battery in the circuit in order for the R27 to run. It should be the same as my R25/2. Several months ago, I was running along just fine...generator working just great. The bike quit on me. I pushed the bike to the side of the road and began to look around. A bad crimp on my battery ground lead came apart. Once crimped back together, I was on my way again. Without the battery ground, the bike didn't run.
    Kurt -- Forum Liaison ---> Resources and Links Thread <---
    '78 R100/7 & '69 R69S & '52 R25/2
    mine-ineye-deatheah-pielayah-jooa-kalayus. oolah-minane-hay-meeriah-kal-oyus-algay-a-thaykin', buddy!

  14. #14
    Liaison 20774's Avatar
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    Are your brushes making good contact with the armature? The small snail springs are supposed to provide adequate pressure on the brushes. If the brushes get too short, the spring may hang up on the brush holder and not put pressure on them.

    I notice you linked to Allan Atherton's photo of the alternator. Do you have one of your own? How does it compare to Allan's photo?
    Kurt -- Forum Liaison ---> Resources and Links Thread <---
    '78 R100/7 & '69 R69S & '52 R25/2
    mine-ineye-deatheah-pielayah-jooa-kalayus. oolah-minane-hay-meeriah-kal-oyus-algay-a-thaykin', buddy!

  15. #15
    Hi,

    Mine looks basically identical to Alan's other than the color of the brushes and commutator, and his is generally "fresher". His looks shiny copper, mine is quite black. I'm not sure that there is a good connection there between the commutator and brushes.

    I took the inner plate off and cleaned and brushed everything I could find. There was some grease and corrosion on the field coil plates and the armature stainless plates. I cleaned the wire ends and put it all back together. Now when it is revved I get about 6.2 V at the blue wire and the charge light dims. Some progress!

    The brushes seem to sit nicely, but they are about a 1/4" shorter than Alan's.

    According to the shop manual, to get the bike started you either need juice in the battery or the ability to get it rolling quick enough to bump it, with the battery disconnected.

    My guess is that some extra resistance somewhere is causing a voltage drop. I think when I get the new brushes I will take it back apart, trace each wire, clean them all and put it back together. I will also put in the new condenser. There are also a couple grounds buried deeper I can clean.

    We'll see...

    Thanks,
    Paul

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