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1980 Kawasaki KL250A trouble starting

Discussion in 'Technical and Troubleshooting Torque' at netrider.net.au started by MuSKeR, Apr 12, 2014.

  1. #1 MuSKeR, Apr 12, 2014
    Last edited: Apr 12, 2014
    Hey all,

    I recently purchased a 1980 Kawasaki KL250A. The story:

    Bought it off a guy who said that one day he rode it into the shed and the next day it just would not start at all. This was 5yrs ago.
    When I got it home I checked the main things. Fuel, Spark, Compression. All three were good. I kicked and kicked but to no avail. I then did the sneaky put a little cap of fuel down the spark plug hole. Kicked over second go.. Was pretty rough but was to be a given being it had been 5yrs since it had been running. Turned it off and tried to kick it over again which it did. Problem is now that when it is cold it is still an absolute POS to try and start. I have done the following and with each thing have tried to start it cold and although I eventually get it, it takes it out of me. I reckon its at least 30 - 50 kicks.

    Fresh Fuel and checked all lines.

    Spark is Excellent.

    Carby taken off and cleaned and checked by a bike mechanic. <--- I thought this would be the savior but no deal.

    Replaced Battery with brand newy. <-- Was told this might help as the engine might be straining with trying to get the ACC going as well... A lot of my hope rested on this. But unfortunately no go.

    Like I said it does eventually kick over but it takes ages. I have tried with choke on and it never seams to work. but I know it does work because when it is running and I pull the choke the revs go up.

    When it is running when cold the idle is so rough.. I cant get it adjusted on the carb at all.. 1 minutes it sits about 1.500rpm then all of a sudden it just starts to rev. Sometimes to 4000rpm. So I try to turn the revs down and then it just stalls. Can never find a happy medium until it's warm..

    The only other thing I can think off (and not sure if possible) is that maybe the compression is to weak ( if that can happen). Only because its really easy to push the kicker but sometime you don't feel anything at all.. ( its hard to explain but I hope you guys get it )

    Anyways I hope someone has some ideas of what I can do to maybe rectify the situation.

    Thanks very much.

  2. Hi Rob, No immediate idea but decompression system on the kick start nags at my mind.
  3. Yea.. Im thinking the worse thing for me at the moment is I don't know when its ready to give a good kick. If that makes sense.
  4. You might need to put a kit through the carbie. reads like the choke mechanism is a bit second hand.

    renew fuel and (most importantly) vacuum lines. Pull the tap apart and check it's all in order.
  5. "but I know it (the choke) does work because when it is running and I pull the choke the revs go up."

    Erratic idle to me indicates too lean on the idle circuit and/or air/vacuum leak. Check pilot jet/ idle circuit for clogging or debris. As @ibast@ibast said, check your vacuum lines. Also check the air boot between carb and head for cracks, holes, splits.

    How well does it run once fully warmed up, and with the choke off? Once fully warm, turning the choke on fully should cause a stumble at idle because of a too rich condition.

    Check valve clearances, this can also cause hard-to-start behaviour.

    Checking ignition timing would also be a good move.

    Good luck.

  6. The pilot jet was cleaned and checked when I had the carby looked at. If it was running too lean could having the choke on technically make it where its meant to be? If that make sense?

    Im thinking a good ol service and tune up might be the way to go.
  7. Yes, and yes.


    A service never hurts.

    A tune up is what you are already trying to do. Stick with it, work methodically and you'll probably solve it. When you do you'll have learnt things about your bike. :)

  8. Thanks mate.

    There should be a screw on the carby somewhere to adjust right?

    Hopefully that will help if it's going to get a good dose of fuel in.

    I'll let you know! Hopefully I get a chance this week.


  9. Can't help with any specifics, but access to a workshop manual would help you heaps. Highly recommend you try to get hold of one. Maybe one for your bike available on the web for download if you haven't got one already. If you do access one, I would double check all the jet sizes against what is currently fitted to the bike, and check the other things I talked about before.

    Good Luck.

  10. Had a play with the bike today. Used 'Start ya *******' and it was a lot easier to start... It also has a Massively sporadic idle which I cant get right.. I took it just for a little run down the street and 3 things happened.

    1. When rolling off the Throttle the Revs dont drop straight away. Its really slow.

    2. When pulling up the idle drops to stall.. ( 3 times it did this )

    3. When in Neutral the idle can sit at 1k rpm then it just creeps up to about 3.5k rpm so I frantically wind the idle down.. then its like once it starts heading down its no stopping it and it just stalls again.

    Any clues?


  11.  Top
  12. No I haven't just left it alone.. Maybe I should. I always panic and am like 'wind down wind down' lol.

    Power feels good. Not sluggish or anything. Only thing is when I roll off the power it a slow drop down. Not instant.
  13. Bit of an update!

    I got myself a manual and I'm telling you this thing is amazing. lol

    So after being able to get my hands on a Compression tester it turned out compression wasn't great. Only about 80psi. Needed around 130 - 160psi.

    Refer to manual and has a full list of things to do if you have low compression.

    Step 1 - Valve Clearance. I get my hands on a feeler cage and get those valves showing and BAM!.... Inlet had NO clearance what so ever.. So after adjusting it to .08mm I Put it back together and I couldn't believe it. Compression was bang on the money 140psi AND it started after the third kick. I thought it may have been to good to be true so i put the bike outside in the 4 degree temperature and let it cool down again and tried it late that night. SECOND KICK.

    It runs amazingly.

    Thanks everyone for the help. Now to get this thing regod!


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