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  • #21
    167.5 should be fine

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    • #22
      Alright, so I dropped the bike at a shop and asked them to check the fuel lines, clean the fuel filter, petcock filter, carb, etc...

      It turns out that my concerns were justified. The primer had indeed lifted the Redkote inside the tank and it was full of smudge and debris. They cleaned it as well as they could, cleaned the rest, checked and changed the plugs. Then they Dynoed it. Results:

      (Sorry for the neck twist):




      A bit under 70PS / 180km/h, or 68HP / 112mph. Now that's a bit more in line with what I'm expecting from this bike.
      Sadly I rode back in very heavy traffic and under an apocalyptic rain (so dense you could barely see) so I couldn't push it, but I'll do it during my next week end ride.

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      • #23
        with the mods you listed you are basically a stage 4. if it dynoed at 68hp you are loosing a bunch somewhere. What was the Torque? I can't post the dyno sheets due to forum restrictions right now. But stage 3 would be around 78hp and around 104 tq,stage 4 would be about 82hp and around 110 tq according to Yamaha published dyno sheets using speedstar stage kits.

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        • #24
          looking at the Yamaha Speedstar dyno charts you are producing a high stage 2 power. Stage 2 is jetting,aftermarket ignition,BAK,and pipes. No hc pistons or cams. I think someone told you a fib about the mods when they sold it to you.

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          • #25
            No, I don't have the torque, the Dyno these dudes have is an antic...I seem to have found another shop with a more modern Dyno so I'll give them a try when I manage to squeeze a bit of time out of my schedule.
            I get your point, but I really don't think that I've been lied to...The person I've bought from is a friend, we are in contact pretty much on a daily basis and meet face-to-face very regularly. I don't think that someone trying to rip me off would have hung around for that long. I recently asked him if he knew a shop skilled enough to work on the engine, and as contact details he forwarded me the invoice of the engine rebuild that clearly lists the piston and cam installation. I also have the pistons box. Of course, he could have purchased the cam/pistons, get them installed, then later on removed before selling the bike, but that's a lot of hassle to add a few hundreds bucks on a sale price, the labor cost would pretty much eat it up.
            I've talked to the shop this morning (the boss wasn't there when I picked it up yesterday...) and they didn't touch the carb. They stopped at the tank/petcock clean-up and spark plugs.

            The shop with the modern Dyno have a reputation for carbs cleaning / rebuild, I think I will send them the bike and get the carb cleaned up, then Dynoed again to see where I stand.

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            • #26
              Well if it has all those mods you are loosing "ALL" of it somewhere. Make sure your clutch isn't slipping. That could explain some or all of the loss. as I said above those mods according to published Yamaha Speedstar Dyno sheets should put you in the low 80's hp and 105 tq or so (up to 110 tq) You also want the graph that show AFR so you know what the state of tune is so you know if any changes need to be made or have them do the dyno tune.

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              • #27
                check this link it has all the stage dyno sheets from Yamaha Speedstar.
                https://www.roadstarclinic.com/filed...5&d=1553021803

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                • #28
                  Thank you for the link Dave, very useful.
                  Mmmmm, that's interesting that you mention a possible clutch slip. I remember clearly the previous owner telling me that he had very hard time installing the Barnett clutch and I do have a very noticeable slip in first gear. Basically, if I accelerate hard in first gear, the clutch will rattle and slip. It will keep spinning and rattling until I decelerate enough to let it engage. It's something on my to do list but I didn't put it at the top of it because it happens only in first and upon hard acceleration.

                  I'll keep proceeding step by step though. I'll get the carb cleaned and re-dyno the bike to see where I stand with fuel lines completely cleaned up, then I'll have a look at the clutch. I'll keep you posted, your input have been invaluable.

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                  • #29
                    That's interesting. I'm not sure I've heard of a clutch slipping in low gear, usually it's the higher gears where it takes more torque/power to increase the speed.

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                    • #30
                      I would look at the clutch first if it is already a known issue in any gear. You will not get a true dyno reading if it has any slippage. A Barrnett is the best available clutch setup and should not be hard to install or make any type of noise or slippage. It sounds like something isn't installed correctly if it is doing what you said.

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                      • #31
                        Yep...pull the clutch and inspect wverything... at this point you might as well replace all the clutch discs and steels (use OEM Yamaha) and the Barnett Spring kit (make sure you get the pressure plate bearing upgrade 7003B. All the issues you have had and $ spent on labor...dyno...etc...I would put a whole new clutch setup in it by someone who has done one of these before (and NOT "some super cool race bike shop that builds drag bikes" find someone who has done this before. Like Dave J said it's a pretty easy and straightforward install....but unfortunately a lot of shops have morons working there).
                        "I'm Ricky Bobby. If you don't chew Big Red.....then Fuck You"

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                        • #32
                          Thank you all folks for your highly valuable input.

                          I haven't ridden the Bobber much lately. First reason is that I retrieved another project bike that was away for some extensive bodywork, I am therefore back on the build and trying to finish it, which is time consuming. Second reason is a new GF who doesn't fancy too much the idea of letting me riding alone or with a bunch of male fellows riders in a country where there's more brothels than gas stations. Bottom line, besides my daily commute I'm mostly riding the Trumpet with her on the back.

                          That being said, I've taken good note of your suggestions and I will indeed replace the clutch plates and springs. Lug Nut, I couldn't agree more with the last sentence of your post above, which is why I'm doing more and more stuff by myself on my bikes. I've watched a few vids of Barnett clutch installation and it seems fairly straightforward, so this is now on my to-do list. I intend to:

                          - Get a new Barnett clutch plate. Reason being that if there's something wrong with the current one, I can change it right away instead of waiting a couple of weeks. If the plate is fine, happy days, I'll have a spare one for an incoming project that will most likely be based on a RS donor bike.
                          - Get a new set of plates. I intend to get a Barnett set, Lug Nut, any reason for recommending a Yam OEM set? Is it just a matter of price, or is there anything wrong with the Barnett plates?
                          - Get a new set of Heavy Duty Barnett springs

                          And obviously a new gasket. Not sure when I'll have the time to get on it, probably when the electrical of my current project is finished and that the bike is torn apart for painting / coating.

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                          • #33
                            You forgot the upgraded bearing for the Barnett setup. For a couple bucks, why not. Another member had a Barnett plate that wasn’t cut properly in the splines (or was cut for wrong spline count) and Barnett replaced for that person. Maybe yours is also wrong and the original installer put it on anyway? Are you certain the belt is not skipping? Like stated I have personally found clutch slippage in higher gears always comes first, most likely your belt is skipping.... just guessing.

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                            • #34
                              Originally posted by daveto View Post
                              You forgot the upgraded bearing for the Barnett setup. For a couple bucks, why not. Another member had a Barnett plate that wasn’t cut properly in the splines (or was cut for wrong spline count) and Barnett replaced for that person. Maybe yours is also wrong and the original installer put it on anyway? Are you certain the belt is not skipping? Like stated I have personally found clutch slippage in higher gears always comes first, most likely your belt is skipping.... just guessing.
                              Thank you for the tip, I forgot the bearing upgrade indeed. I don't think I have belt skip, when I did the build I ditched the old one that had a few dents and bought a new, heavy duty one and it is still in pristine condition. I'll look into though, after cracking the clutch. I'm trying to deal with the potential issues one by one so that I can progressively tick them off for good.

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                              • #35
                                I've ordered the Barnett clutch, the clutch plates kit, the heavy duty springs and the bearing.
                                Dumb question: is the torque for the plate bolts the same for the heavy duty springs than for the springs provided in the kit (5.8 ft.lbs)?

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                                • #36
                                  Yes it is. The Tq value does not change when using the heavier springs so whatever value they say in the instructions is what you use. Also make sure to convert the Tq value to inch Lbs and use an inch lb torque wrench. Do not over tighten or you can easily strip the threads in a hole

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                                  • #37
                                    I've received the last parts on Friday, I now got everything I need for the full replacement.
                                    Unfortunately I gotta fix my front brake lines first. The dudes who did the job used some pretty cheap crap and I've been regularly losing fluid on long rides.
                                    I've been arm wrestling with them for a while on the issue but long story short, the lines finally gave up for good and the bike has been bleeding brake fluid for days now.
                                    I took the piss and will get a full set of Goodridge lines installed before working on the clutch. First thing I'll do after the replacement is to ride the bike as fast as possible and that's not something I keen on doing with questionable front brakes :-/

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