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    Another CB650 project

    Nothing as grand as friend Akckhim's project, likely just a freshening up of a long dormant ride. But I really haven't decided.

    The bike is an 81 that I obtained free and gratis from my good buddy George. He replaced it with a newer V-Star and decided he needed the garage space so being the good bud that I am I offered to help him out.

    The bike is complete and in fairly decent shape but it is a non runner with a set of dodgy carbs. They were cleaned a year or so back but I think a few key parts went a missing. I think I may need a replacement set but that is yet to be determined.

    So today I got back into wrenching after a good year off. I forgot how much I enjoyed it even in a stone cold garage hovering near the freezing point.

    I took off the windscreen and backrest and spent a good few hours cleaning everything in ready reach. The battery was new last year but is dead so its currently on the charger in hopes it will come back to life.

    I think the bike will just be a flipper for me that will fund a new clutch and insurance for the FZ but who knows. It appears to be a comfortable little ride so it might end up being me ride for 2015. I'll let you know.

    Pic to follow sorry but I am having issues with photobucket and this new forum format.
    Attached Files
    Last edited by Guest; 01-24-2015, 10:28 PM.

    #2
    Well despite temps dipping to -17C or more over the weekend I made it in to the man cave Sunday afternoon and again yesterday on our first "family Day" holiday.
    Got her up on the lift and started some disassembly.

    I am planning on keeping it stock but perhaps "modernizing" just a tad. A new "euro" bar for sure and perhaps LED turn signals. The tank has a dint or two and there is some surface rust appearing so a quick respray may be in order as well.

    But first things first, she has to run again. So I started by pulling the carbs. You think Suzukis are difficult....try a CB. Mucho cursing required.

    So these carbs are Keihin PD 50 with mechanical slides. A bit more complicated for teardown than the Mikunis we all love. There are rods connecting the slides and two connecting each pair of butterflies, and, of course, they are locktited in place. Eventually I get them all apart, only to find each carb has an air cut off damper that is a little rubber diaphragm and piston. These are all "glomed up" and stuck in place with rust and crud. The rubbers are all worn and I all I can see is dollar signs for new parts. Confirmed at $20 a piece when I check. Yikes.

    Fortunately, more investigation indicates these gizmos are not essential for proper operation so they can be blocked off so that is what I will do.

    These carbs also have some pressed in jets which are difficult to remove so I am hoping the soak will get them clean enough. Fingers crossed.

    So the project has officially started. Stay tuned for some pics soon.

    Cheers all.

    Comment


      #3
      You must have a heated cave.
      I don't think the piston in the lift would work in my frosty garage.
      Spyug, don't know if you need the help but www.cb750c.com is an excellent site.
      2@ \'78 GS1000

      Comment


        #4
        Well Steve, no heat in my cave either but Sunday was sunny with no real wind around here. The heat from the sun seemed to help with the mood if nothing else. I was wrapped up in 2 or 3 heavy layers so toasty enough. It did get bloody cold when the sun went down, however.

        Thanks for the heads up on the 750 site and yes you are correct it is a wealth of useable info.....much along the lines of this crazy place. I actually found the info about those silly air valve gizmos there. It seems these carbs were shared with many of the 750 models so they are well known.

        One thing that I did find interesting about these carbs is that for some reason parts for those that are used in 750 models are cheaper than the same thing for the 650. A little bizarre. As an example, float bowl O-rings for the 650 list for $16 each but a 4 pack for the 750 are only $16. Go figure.

        Next week buddy George (the original owner) and I are taking a road trip to Sirius Consolidated up in Kitchener to source some o-rings and float bowl seals as they are reputed to have everything needed along with 250,000 other bits and pieces. Should be interesting.

        I am hopeful that I can get her running soon thereafter as the plan is to have her ready to go for the spring selling season.

        Yesterday afternoon I had some time to spend so after a trip to Princess Auto which I haven't been to in over a year, I also stopped in to Car Quest's paint store to check on what is available for redoing the tank. I have done my last 5 or 6 bikes in rattle can then covered in 2 part epoxy clear. I had been using HVLP
        equipment but I am getting lazy in old age and was interested in sourcing a 2 part clear in a can. Low and behold they have it and at a quite reasonable ( I thought) $22. With a mixed "shelf life" of 36 hours and cure to recoat of 1 hour I should be able to lay down a few coats. I'm looking forward to trying it out.

        In an effort to try and update the look of this bike, I am contemplating going with the all black look once again ( as I did for the 750 "Black Booty") which will include the complete engine and front forks. I'm not normally a fan of chrome on bikes but I think the front and rear fenders on this one will contrast nicely with satin black body and engine. I guess we will see.

        I am actually getting quite enthused about this project after taking all of last year off from riding and wrenching so hopefully I'll manage to crank this one out in record time ( for me at least).

        Stay tuned.

        Comment


          #5
          Hmmm...doesn't seem right about the gasket pricing discrepancy.


          I have been up to Sirius a couple times and they were very helpful.
          It never made sense until you start adding up the ridiculous Canada Post costs.
          Easy to miss the store being in one of those industrial malls.
          2@ \'78 GS1000

          Comment


            #6
            Talking with the guys on the 650 board and they mention this is (for some strange reason) common. So the recommendation is to ask about parts for a 750. I'll see what Sirius has to say.

            I also notice they have a really good price on Kenda tires with a pair going for about $130. That interests me. I don't know anything about them but I hear equal parts yay and nay. As the other Steve says, being cheap they are likely crap but in this case they will do as I don't intend on keeping it.

            I'll let you know how I make out.

            Cheers.

            Comment


              #7
              Well this week I got the carbs all stripped and dipped. They had, "supposedly", been professionally cleaned about 2 years back but once back on the bike it wouldn't run and my buddy parked her in frustration.

              I think I know why she wouldn't run:

              So I plan on reassembling tomorrow and getting them back on by Sunday for a test fire. Hopefully there will be a lot of "suck, bang and blow" in the old man cave.

              I'll let you know.
              cheers.

              Comment


                #8
                Well not a lot got done, the last few weeks, other than de rusting the inside of the gas tank and learning to bang out some dints. Last weekend I did find time to get the carbs back on, finally.

                I'm glad to report that the bike fired right up with minimal fuss but almost immediately started ****ing gas all over the place. Most of it coming from the #2 carb which houses the "accelerator pump" a device used to pour in fuel at higher revs. A couple of float bowels were leaking through the drain screws too. So the rack had to come off once again.

                At first I was a tad baffled as to what was going on but after a quick referral to the manual it became obvious. I had forgotten a crucial o-ring that sits on the rim of the #2 float bowl to seal the passage that feeds the "rail" that directs gas to each of the high speed "enricher" jets. It is an odd sized o-ring but fortunately for me I some how have a bag of about 25 of them in my o-ring stash. I don't even remember where they came from.

                So after installing the o-ring the carbs are good to go again but they will stay off until I get some fresh paint on the engine block. I am not a fan of silver blocks and shiny side covers so the engine will get a dose of flat black or possibly 'crinkle" finish if I can find it.

                With the weather heating up a tad it is comfortable to get out to the man cave again and I'm on track to get this puppy going and out the door. Hopefully the revenue it will generate will fund the return of the FZ this season with a good clutch. I can't wait.

                Comment


                  #9
                  Originally posted by spyug View Post
                  Well not a lot got done, the last few weeks, other than de rusting the inside of the gas tank and learning to bang out some dints. Last weekend I did find time to get the carbs back on, finally.

                  I'm glad to report that the bike fired right up with minimal fuss but almost immediately started ****ing gas all over the place. Most of it coming from the #2 carb which houses the "accelerator pump" a device used to pour in fuel at higher revs. A couple of float bowels were leaking through the drain screws too. So the rack had to come off once again.

                  At first I was a tad baffled as to what was going on but after a quick referral to the manual it became obvious. I had forgotten a crucial o-ring that sits on the rim of the #2 float bowl to seal the passage that feeds the "rail" that directs gas to each of the high speed "enricher" jets. It is an odd sized o-ring but fortunately for me I some how have a bag of about 25 of them in my o-ring stash. I don't even remember where they came from.

                  So after installing the o-ring the carbs are good to go again but they will stay off until I get some fresh paint on the engine block. I am not a fan of silver blocks and shiny side covers so the engine will get a dose of flat black or possibly 'crinkle" finish if I can find it.

                  With the weather heating up a tad it is comfortable to get out to the man cave again and I'm on track to get this puppy going and out the door. Hopefully the revenue it will generate will fund the return of the FZ this season with a good clutch. I can't wait.
                  Bought an 80' couple of weeks back, needs carbs cleaned but it fired off and ran a little so I'll call it a win. Good luck with the project.

                  Comment


                    #10
                    And good luck to you too. Nice looking bike, are you keeping it stock or doing some "alterations"?

                    I was planning on doing some modernization (new turn signals, brake light and handlebar) and fancy paint to make it more saleable but I think I'll leave it pretty much stock. Maybe just put on a stainless steel front brake line as I think that is a really good improvement for brake feel and performance.

                    I half ways would like to keep it but I need to flip it to fund repairs and insurance on the FZ. I had to pull the FZ last season for lack of funds so I'm looking to this project to get me back in the saddle.

                    Now I don't know if you have worked on these Keihin PD carbs but they are different than CV type Mikunis we are used to. Not hugely different but enough to be somewhat confusing at first. If you haven't already, you might want to join the CB650 forum as like the GSR, it is a wealth of info and there is information on these carbs. http://www.hondacb650.com/index.php There are manuals there if you don't have one.

                    The biggest difference with PDs is they have mechanical slides not vacuum controlled. The slides are ganged together on a rail as you will see and to ungang the carbs you also need to remove this rail and the rail that the butterflies are mounted too. Fiddly but doable. They also feature that "accelerator pump that I referred to and you can learn more about it in this carb cleaning tutorial http://www.cb750c.com/publicdocs/Sea...anual_revG.pdf
                    This site also has a wealth of information and has articles explaining another "oddity" the air cut off valves http://www.motorcycleproject.com/
                    This article refers to a source for carb parts http://www.hondacb650.com/viewtopic....t=6553&start=3 The company Sirius Consolidated is local to me just about an hour out of town. I haven't been there yet myself but I will need to take a trip soon. They do a lot of business with the folks in the US I understand.

                    Hopefully that will help you get those carbbies sorted. Give me a PM if you need any help, I think I have them sussed now.

                    Cheers mate.

                    Comment


                      #11
                      I should mention that while the PDs have a pressed in idle jet and the manuals tell you to leave it in place and dip the whole carb body, it is possible to remove it. I strongly advise that you do that as I found out for myself today.

                      I did not pull the jets 2 weeks ago when I dipped them and I though they had been cleaned well enough as I could blow air through them. The bike ran when I started it on the weekend but it didn't idle. No biggy I thought as the carbs still needed synching. But something was niggling at me.

                      So today I pulled them (pliers with tape to not chew up the brass. Twist slightly and pull straight out) and I am glad I did as each of them had plugged holes and the passages were a little cruddy. They are swimming in carb cleaner at the moment and I will have to try and clean the passages by hand as I don't feel like stripping them again.

                      Just a word of advice for you.

                      Comment


                        #12
                        The guy at sirius is very helpfull and they stock everything, my GF is from St-Catharines and we stop there almost every trip on your way back.
                        The price are little higher than a year ago but still worth it, the exchange rate is not helping us.
                        Like Steve said its easy to miss the place.
                        Marc
                        AIR COOLED MONSTERS NEVER DIE
                        1978 GS1000C X2
                        1978 GS1000E X2
                        1979 GS1000S
                        1979 gs1000
                        1983 gs400e

                        Comment


                          #13
                          Thanks Marc. They are only about an hour away from me but their hours of operation at the retail store are odd only being open Tuesday through Thursday in the afternoon. I will get up there one of these days. They must be doing a great job as they are highly spoken of by the Honda forums from twins to 750s.

                          So I got the carbs all back together again and tried to get them back on the bike with the stock airbox. Boy was that four fruitless and frustrating hours yesterday. I always though GS carb to airbox installation was tough, but nothing on the CB. It is horrible. Absolutely no clearance. The airbox plenum will just not go back far enough before it jams against the frame. It must be doable but I can't figure it out.

                          When first getting on the CB forum I wondered why so many guys were hell bent on switching to pod filters and now I know why. Strangly , when my buddy bought the bike, it came with pod filters but it never ran right so he hunted down a stock airbox system. He had some "pro" install it.

                          well the weather is supposed to get warmer by mid week so we are planning on trying again Wed. afternoon. George will come over for "moral support" but more importantly, replenishment of beer which as we all know is highly important to aid in the necessary cursing to get the bloody things on.

                          I'll let you know how it goes.

                          Comment


                            #14
                            I owned a cb650 few years ago, it was a ''bobbed'' custom with spoke wheels.
                            It had cheap emgo pods and cheap shorty muffler.The bike ran fine except in the low temp in october, i was a little lean.
                            I cannot remember the jetting.
                            Marc
                            347iv5d.jpg
                            AIR COOLED MONSTERS NEVER DIE
                            1978 GS1000C X2
                            1978 GS1000E X2
                            1979 GS1000S
                            1979 gs1000
                            1983 gs400e

                            Comment


                              #15
                              Well the story continues...slowly.

                              I got the airbox back on last weekend and the bike would start under choke but would not idle. This weekend it would start occasionally without choke but would still not idle and often died out without warning. So with my many years of experience farting with carbs, I deduce they are not yet clean and will need to come off for another dipping. I was hoping that would not be necessary but it is what it is.

                              On a more positive note, I have fixed the dints in the tank (after cleaning it) and have primered it along with the side covers. I had thought about doing the tins in black to produce Black Booty III but I got a notion to go with dark blue this time. For a bit of pizzaz I have been thinking about doing a tank graphic on each side of a rippling chequered flag.

                              Thank goodness for Youtube as I was able to watch several vids showing me exactly how to do it using a "mask". Basically a sticky backed film that is laid on the tank and from which alternating squares are cut out to allow the secondary colour to by sprayed on (white) giving the chequerboard affect. And fortunately for me, I had a stash of the film sitting on the shelf in my workshop ready to go.

                              So weather and time permitting tomorrow I will do some painting, before yanking off those darned carbs.

                              She's coming together slowly as I mentioned but I am still relatively on track for having her saleable by the end of April. As long as she will decide to run once again.


                              More to follow.

                              Comment

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