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Engine breather questions. Does it work across multiple years?

Discussion in 'The Garage' started by Prisondawg, Aug 9, 2019.

  1. Prisondawg

    Prisondawg XS650 Enthusiast

    I currently have a 1978 engine breather on my 81 engine.

    I feel like my engine has too much compression , it’s super hard to kick , and sometimes it kicks back, I’m wondering if perhaps the symptoms are caused by the breather being from the wrong year.
  2. Bushyeyed1

    Bushyeyed1 Cafe Racer

    Not an expert per say but I wouldn’t say the breather is not causing you high compression because it isn’t really the limiting factor in the compression section. Before I knew the proper way to adjust my valves on the xs650 i adjusted both exhaust and or both intake at same TDC and when I went to kickstart about broke my frickin ankle with the kick back.
    Last edited: Aug 10, 2019
    B_Crabaugh likes this.
  3. B_Crabaugh

    B_Crabaugh XS650 Addict

    So thaaaaats what I did wrong! Haha yeah did that more than a couple of times.
    Bushyeyed1 likes this.
  4. Bushyeyed1

    Bushyeyed1 Cafe Racer

    Yeah you have to adjust one side exhaust and intake valves and then rotate and do the other, but the side that has clearance first. Here is a link on YouTube It was hard for me to understand what that meant by clearence but if you rotate the engine a few time and watch the valve move you will understand better
    Last edited: Aug 10, 2019
  5. XSLeo

    XSLeo XS650 Guru Top Contributor

    The breather has little to no effect on compression or the ease of starting. As the pistons move down, air in the crank case is pushed out through the breather. As the pistons move up air can flow back in. On the early models the long rubber hose acted like a filter. On the later the rubber hose was routed to the air cleaners so the breather could get filtered air.
    As mentioned valve adjustment does have an effect.
    When you do the valves it's recommended you adjust the cam chain tension first. Adjust valves second. Then on to ignition.
    On your 81 if you still have the stock TCI you can check the timing at idle and full advance. A bit hard to adjust but it can be done.
    If you have an aftermarket ignition you may have the timing to far advanced. This makes it hard to start and kick back.
  6. Prisondawg

    Prisondawg XS650 Enthusiast

    I have the stock TCI. I did set the cam chain first (flush with the threads) I set the valve clearance with feeler guages, by turning the engine to the highest point per stroke.....maybe I'm doing it wrong , my bike often starts in one kick, but every so often it'll be having a hard time and it's only when I have to kick it multiple times that it'll start to kick back. Often if I open the throttle while kicking it will make it start.
  7. Bushyeyed1

    Bushyeyed1 Cafe Racer

    Yeah you can’t just go off the piston at top dead center you have to go off the cam opening the valve for adjustment. Just watch the video and it will make it easier to understand. Both cylinders don’t open at the same time. So you have to do one side then rotate back around to tdc and do the other.
  8. mike in idaho

    mike in idaho XS650 Enthusiast

    When you're getting ready to kick it put it in second gear and roll it backwards until you feel one of the cylinders come up against compression. Slip back into neutral and kick it. Positioning the crank like that lets you get about a half turn on the crankshaft before you come up against compression, time to build up momentum to spin it through easier.

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