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Bringing My '79 Bonneville Special Back to Life

Discussion in 'Triumph (Classic)' started by Tulsaalva, Oct 14, 2007.

  1. Tulsaalva

    Tulsaalva

    Joined:
    Sep 3, 2007
    Podtronics Installation

    Thanks, Les! The two wires were well insulated but just to make sure I used a closed-end rubber tube which covered them tightly and tucked it up under the frame tube.

    The installation of the Podtronics unit went nicely as well. I removed the tank, side covers and air filters to afford easy working room.

    I mounted the Podtronics unit on the front frame tubes just under the oil cooler, where it fit very nicely with the fins "into the wind."

    The wires were all too short but I raided the '82 Porsche 924 salvage car and was able to match quite closely the colors of the Podtronics wiring, if not the Triumph's. I soldered and heat-shrink-wrapped the connections and tie-strapped the wiring to the underside of the main tube of the frame.

    I was able to re-route the four wires which connected to the original rectifier to a position near the back of the tank on the left side of the frame. I connected the three yellow wires (according to Podtronics' diagram) to the Triumph wiring with spade connectors. I was lucky to find connectors which had a plastic weather guard and which fit perfectly the Triumph connectors. It seems to be a pretty-much weather proof installation.

    The power wire was a bit more of a challenge. It is a female connector quite a lot larger (3/8 inch wide) than the spade connectors that I had available. However, I was able to remove the male spade connector from the Zener diode, which left a convenient hole opposite the plug-in end. I ran the stripped power wire through the hole and soldered the connections on each side of the spade, finally covering it with heat shrink-wrap. It plugged into the brown/blue wires of the rectifier like it had been made for the job. Come to think of it, I guess it was. :)

    The ground wire was quite easy. I crossed it under the upper frame tube to the right hand side and, using a circular connector, connected it to the negative pole of the battery along with the ground wire.

    The bike started and ran like a Triumph on the second kick with no fluctuation of the lights.

    Thanks for recommending the Podtronics unit, Les. I think I'll probably use one on the Norton when I begin its resurrection.

    Al
     
  2. frankdamp

    frankdamp

    Joined:
    Oct 7, 2005
    Al:

    It has been interesting reading your saga. As a matter of interest, an old school friend of my sister lives in Slidell, LA. He had a very nice 79 Bonneville that was destroyed in Hurricane Katrina.

    He recently took a wild flyer and bought, sight unseen except for photos, another 79 with only about 5000 miles from new.

    He speaks very highly of an outfit in New England someplace called Frank's British Bike Barn, where he found the bike he now has. Fortunately, Slidell evaded the worst of Gustav and Ike and everything's OK.
     
  3. Tulsaalva

    Tulsaalva

    Joined:
    Sep 3, 2007
    Thanks for the nice comment, Frank. I've printed a number of the posts on this thread and added the pages to my service manual. It's my hope that this thread may help someone else in a future Bonneville resurrection.

    I still have the right turn signals to sort out. I've had the switch apart, where I found a mud-dobber's nest. I cleaned that out with contact cleaner and found no other obvious problems. Unfortunately, I was so sure the insect's nest was the problem that I didn't do any further investigation. The right signals still don't work.

    I found the problem with the speedometer. It was in the drive. I need to get that problem on the project list, then the bike will be finished.

    The bike seems to be quite reliable now and Sixteen is in love with it again, so I guess the idea of selling it (expressed above) is off the table. He uses hand signals and seems to get along just fine. One nice thing about hand signals is that one can't leave them on unintentionally. :)

    I had planned to start on the Commando LR when the Triumph got to this point but I recently rescued an '87 Porsche 944 five speed from a field and have been cleaning that up. I must have pulled the equivalent of a bale of grass hay out of the nooks and crannies so far!

    I've bought the parts to replace the hoses, belts, pulleys, brakes (stainless steel lines, of course), and have had the radiator cleaned and rodded. I've replaced the pesky odometer gear and pretty-much gotten the car ready to paint gold pearl white.

    As I mentioned above, Sixteen is enrolled in a motorcycle mechanics' course at Tulsa Technical College. He has talked to his instructor about using the Norton for his class project. The instructor was enthusiastic but has since fallen ill and not been in class for a week. If this comes to pass, perhaps Sixteen can get on here and write of the project as it progresses.

    Al
     
  4. Tulsaalva

    Tulsaalva

    Joined:
    Sep 3, 2007
    Rough Running

    Okay, folks, another puzzler has reared it's head. The bonneville has started to run poorly. It starts readily if the throttle is held slightly open but will not run smoothly nor will it idle.

    In riding the bike, it seemed like fuel starvation might be the problem. Suspecting the fuel lines might have been fouled with rust or paint chips left from twenty-five years of sitting empty, I drained the tank. It was quite clean inside.

    In checking out the petcocks, I found them quite clean, including the metal screen which encloses the upright pipe. But here's the interesting thing: I blew compressed air into the petcocks from the bottom, the side which connects eventually to the carbs.

    The left petcock will flow air only when set to "On," not to "Res."

    The right petcock will flow air only when set to "Res." not to "On."


    Neither will flow air when set to "Off." That's good, right?

    I went to LaNelle's shop. She has after-market replacement petcocks in stock which are pretty chrome and cost about $25.00. The negative side is that they only have an "On" and an "Off" position, no "Res." Another is available from the same company with all three at the same price. I placed an order for the three-way switched ones.

    I also bought two in-line fuel filters and will install them just for insurance, although there's no indication of any foreign matter in the fuel system.

    What's going on???

    Al
     
  5. kommando

    kommando

    Joined:
    May 7, 2005
    Sounds like the pilot jets are clogging up, the latest fuel makes them very prone to clogging.
     
  6. Tulsaalva

    Tulsaalva

    Joined:
    Sep 3, 2007
    That is a possibility I'd considered, Kommando, but had discounted it after I found the system so clean. Still, it is a good idea to go ahead and clean the carbs while I have the fuel system apart.

    Will I need to remove the carbs to clean the pilot jets? Do you have any specific tips on how to go about the project? (I'll read the manual, of course.)

    Should I be prepared with a gasket kit before beginning the project? I had the carbs cleaned when we originally started the project. It cost over $400 but included other work as well. I considered taking the float bowls off and looking for grime. Will I need new gaskets for that?

    Thanks for the tip, Kommando! It's hard to find pure gasoline here in Tulsa but there are several stations which sell it. Most offer 10% ethanol. We used "gasohol" when we first returned the bike to the road, but have used pure petrol for the past couple of tanks. It ran much better until this most recent challenge.

    Al
     
  7. L.A.B.

    L.A.B. Moderator VIP MEMBER

    Joined:
    Nov 20, 2004
    Re: Rough Running

    I'm not sure if the petcock/tap in the photo of the bike (on page 2 of this topic) is the standard Triumph item? And presumably the L/H one is the same type as the R/H one, so I can't give you any answers as to why they are only drilled to flow at one position? Originally one petcock would have been for "(main supply) on & off" and the other would have been "reserve & off".

    Edit: After closer examination of the petcock in the photo, there is a chance it is the correct item. Are there any markings on the back of the bodies (BAP?)?
     
  8. L.A.B.

    L.A.B. Moderator VIP MEMBER

    Joined:
    Nov 20, 2004
    After digging out one of those BAP taps, do those petcocks/taps actually have RES (or RESERVE) marked on them, as well as ON & OFF?

    As the one I've got is a single supply tap, - even though the lever has three positions = "ON -OFF" and a third position with no marking that is also ON with the lever 180 deg. away from the other ON position.
     
  9. Tulsaalva

    Tulsaalva

    Joined:
    Sep 3, 2007
    I need to work on my powers of observation, Les.

    Both taps have a BAP logo in raised letters surrounded by an oval on the back.

    On the left tap, "ON" and "OFF" are stamped.

    On the right tap, "OFF" and "RES" are stamped.

    Both have three positions.

    Only the left petcock has a tube extending upward inside the wire screen filter.

    I believe I understand how this is intended to work but perhaps there is a crossover fuel line missing? My BMW has a fuel line connecting the left fuel line to the right one, but it has all three positions on both taps. The Commando also has a crossover fuel line.

    Al
     
  10. L.A.B.

    L.A.B. Moderator VIP MEMBER

    Joined:
    Nov 20, 2004
    Yes, there should be a crossover pipe between the fuel line banjo fittings on each carb, as the banjos would normally have double spigots, so that either the "main" or "reserve" tap/petcock feeds both carbs.
     
  11. Tulsaalva

    Tulsaalva

    Joined:
    Sep 3, 2007
    Yes, Les! Hidden down there behind the carbs is the crossover line. So... since the fuel tank was full at the time the bike was running poorly, it wouldn't have mattered where the taps/petcocks were set, both carbs would have been getting enough fuel.

    Therefore, there must be another problem. I guess it's time to remove the float bowls and look for squirrels' nests... or something similar. Have you any suggestions on what I should look for?

    Al
     
  12. L.A.B.

    L.A.B. Moderator VIP MEMBER

    Joined:
    Nov 20, 2004
    It's difficult to say what it might be from your description of the symptoms, but start with the easy stuff first, and, as kommando has suggested, check the pilot system, and I would also suggest checking the inlet rubbers and inlet balance pipe for splits? Also check the carb choke linkage is shutting both plungers completely, also check the condition of rubber gaskets on the ends of the choke plungers, as they are known to disintegrate when they get old.

    Another thing, check the floats as they can split and let in fuel.
     
  13. Cookie

    Cookie

    Joined:
    Oct 5, 2008
    I'm not sure how much room you have to work but I can pull my float bowls on the bike. I'm sure you can remove the air cleaner unless this quite unlike my old Commandos. If you can do that you can remove the pilot air screw and crank throttle and choke wide open. Then you ciould apply air to the pilot jet circuit and see if it comes out all the proper holes.
    If you have to clean the jets they are so miserable unless you got lucky the crabs have to come out.
    I soaked mine in carb cleaner, blew them out, used spray cleaner, blew them out again, and finally used the old sixties trick of applying a guitar string to clear one. We all played guitar back then and I still have several.
    If you just cleaned them a bit ago it seems they would not be too bad.
    I'm pretty sure my Norton had sat with fuel in it for ten years or so, no real surprise one was good and plugged.
    I only know a couple more tricks for those, boil in water to get the fuel to loosen, and finally the last ditch stand of driiling from the back side and plugging the hole up after.
    I like to put a new kit in but you may not need to if it has just been done.
     
  14. L.A.B.

    L.A.B. Moderator VIP MEMBER

    Joined:
    Nov 20, 2004

    Cookie,

    These particular carbs are Amal MkIIs ('79 Bonneville) which have a different pilot system with screw-in pilot jets.

    http://www.amalcarb.co.uk/carbDetail_mk ... CarId=null
     
  15. Cookie

    Cookie

    Joined:
    Oct 5, 2008
    Ahhhh,

    I guess I'm jammed on Concentrics. I can remember very little of working on my earlier Amals.
    I'm already thinking of picking up another older bike to restore so the more i can pick up the better.
    I'm learning a lot here,

    Thanks
     
  16. Tulsaalva

    Tulsaalva

    Joined:
    Sep 3, 2007
    Sixteen took the Special to his motorcycle mechanics class at Tulsa Tech. They cleaned the carbs and removed a "blob" from the left one. They are cleaning the tank (again) and have filters installed in the fuel lines.

    Sixteen thinks he may have gotten dirty gas at our favorite "Pure Gas" (no alcohol) station because the bike started running poorly shortly after leaving there.

    Although the Triumph will start when kicked, Sixteen has not been able to get it to run smoothly or idle once it's started. Of course, the carb adjustment was lost in the cleaning.

    Has anyone determined what is a good "initial setting" for the mixture control? Often manuals suggest opening the adjustment "one and a half turns" or some other setting to arrive at a starting point.

    I use a system on the '85 R80RT which works like a charm. I screw the adjustment screws in until they just seat lightly. Then I open them one and a half turns. I disconnect one spark plug wire, leaving the dead plug in place. I insert a modified plug into the plug wire connection and using an alligator clip, secure the electrode to a cylinder fin. (Suggested by a member of this board.)

    I increase the idle adjustment on the live plug side until the bike will idle at about one thousand on one cylinder. I turn the mixture adjustment screw back and forth until I achieve the highest RPM. I then very slowly lower the idle adjustment until the engine stalls.

    Then I reverse this procedure for the other side. When the dead plug is reconnected, the bike idles smoothly at about 900 RPM. If the idle seems too high I lower it by turning the idle adjustment screw one width of the slot at a time, making sure the screws have been turned equally.

    If the smoothness doesn't seem optimal, I ride the bike until it is well warmed and do the procedure over again, using the first adjustment as a starting place.

    The problem is that I've never used this method on a vertical twin and have no idea where to start with an initial adjustment. Does anyone have any tips on adjusting the Bonneville's Amal Mk II Carbs?

    Al
     
  17. L.A.B.

    L.A.B. Moderator VIP MEMBER

    Joined:
    Nov 20, 2004
    One and a half turns does appear to be a good starting point, and I can't see why your tuning procedure wouldn't work just as well with a vertical twin as it would do with a flat twin.

    MkII tuning info: http://www.hitchcocksmotorcycles.com/am ... nc_ht.html

    Quote:

    "2nd: Pilot jet
    The pilot system governs engine tickover and can affect pickup and transmission to the main system. Choose a jet that when the engine is set for steady idling, the pilot screw is one and a half turns from its seat. If the adjuster is further on its seat, a larger jet is needed, conversely if the adjuster is screwed out a long way a smaller jet is needed. There are two alternative pilot jet locations; the one in the float bowl is generally considered best for four stroke engines, that located in the body beneath the air tube usually best for two stroke engines. This is not a hard and fast rule and the reverse may sometimes be the case. Irrespective of engine type, when the carburetter is mounted in a down draught attitude, the pilot jet should be placed in the mixing chamber body."
     
  18. Tulsaalva

    Tulsaalva

    Joined:
    Sep 3, 2007
    Thanks, Les. I'll turn this information over to Sixteen. I'm sure he'll get it right.

    Al
     
  19. Tulsaalva

    Tulsaalva

    Joined:
    Sep 3, 2007
    Sixteen cleaned and rebuilt the carbs at the Tech school and brought the bike home. Yesterday we used the old BMW method to balance the carbs and the Bonny is running smoother than it has since we've had it running.

    Next week Sixteen is out of school for Thanksgiving (celebrated on the 4th of July by Brits, I've been told...). :) We're going to use the time to pull the drive train on his 924 and replace the rear engine seal, the clutch, the shift linkage, and the half-shafts. Since the Triumph is running beautifully again, he'll have transportation. The weather looks good so far.

    Al
     
  20. L.A.B.

    L.A.B. Moderator VIP MEMBER

    Joined:
    Nov 20, 2004
    That's good.


    4th of July?

    It's just the day between the 3rd and 5th of July to us Brits, Al, as there's no "Thanksgiving day" in the UK, but I hope you all have a good one!
     

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