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  1. #21
    Moderator dirtdigger's Avatar
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    Sound is normal, its the primary chains rattling. it will get a little better once you get it running right but you will always hear it. By the way the rpm hangs when you rev it , its still either really lean or the ignition advancer is not working right. With the problems you keep finding with the carbs I would tear them back apart and clean them again. Seems like you have stuff still plugging things up. Also look into putting an inline fuel filter in there to keep debri from the tank going to the carbs. I still wouldnt count out a vacuum leak either by the way its running.

  2. #22
    CB750 Member tdubsy's Avatar
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    Quote Originally Posted by dirtdigger View Post
    Sound is normal, its the primary chains rattling. it will get a little better once you get it running right but you will always hear it. By the way the rpm hangs when you rev it , its still either really lean or the ignition advancer is not working right. With the problems you keep finding with the carbs I would tear them back apart and clean them again. Seems like you have stuff still plugging things up. Also look into putting an inline fuel filter in there to keep debri from the tank going to the carbs. I still wouldnt count out a vacuum leak either by the way its running.

    Ok awesome. I was going to try and see if i can get it a little better with the mixture screws. I reset them back to factory spec. But I found an extra half turn helped when the problems were worse.

    I've essentially taken them apart 4 times now. The 1st time was almost a complete rebuild they were already in great shape inside with clean bowls but I have limited knowledge of the bikes history so I essentially wanted to start from scratch there. I have a feeling that I clogged up the accel pump myself as I didn't think to blow out the holes in the pump bowl after the first pinesol soak.

    I did have a pretty major vacuum leak so I replaced the boots when I did the 1st rebuild and I've double checked a few times since with WD-40 and there is no sign of any more.

    I would consider myself fairly mechanical minded but all this is new to me so I'm learning tons, mostly from mistakes or things I've missed. But considering that the bike would need to Idle at 3500 RPM just to be able to ride around my parking lot I'm pretty happy with the improvements so far. And I'm starting to get pretty quick at removing the carbs which will come in handy as I plan on hopefully getting pods to work after I get the bike running properly and I will be constantly switching jets around.

    Fuel filter is also on its way, There was a plastic on of before but I managed to break the end off trying to remove the hardened fuel line.

  3. #23
    CB750 Member tdubsy's Avatar
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    Just took the bike for a spin around my parking garage, didn't adjust the mixture screws yet

    Am I right in thinking I should be able to roll around on flat ground at idle with using only the clutch and no throttle? I have to rev up to around 3000 rpm to get moving. and then I can start to bring it back down as I roll away

    Also while going up a slight hill in 1st (probably just a touch to steep to push the bike up by myself) around 3000rpm the bike suddenly started to have a bit of trouble going up. So I pulled in the clutch and instead of recovering the bike just kept bogging down and died.

    Are these symptoms inherent to an over lean condition?

  4. #24
    Moderator dirtdigger's Avatar
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    Like said stop, if you havent already, check compression make sure engine is healthy. Check ignition timing/dwell, point gap, advancer free and working. Ignition system just as important in the way the bike runs.

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