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Starter turns, but only catches sometimes.

Discussion in 'Technical and Troubleshooting Torque' at netrider.net.au started by Troy123, Jul 26, 2013.

  1. 1991 honda cbr250rr -> Thank you for your time!

    When I go to start my bike, all the lights and everything turns on fine. When i press the starter is sounds normal, however frequently it wont catch.

    For a few days, I would do a very slow roll start in gear 1 and it would start up fine, and then for the rest of the day it would be okay.
    However, yesterday after not riding for only an hour it would not start in neutral, gear 1 or a gear 1 roll start down a hill. However gear 2 roll start down the hill worked.
    When i got home, I bought a new battery (as a mechanic suggested), when i put the new battery in at night (very cold), it started up fine first time ( this sometimes happens). However in the morning I had to roll start it in gear two ( after trying neutral and gear 1 starts) and it started up fine. However 4 hours later after work, It would not start. I got a friend to push me and i tried to start in in gear 2 roll start and it didtn work. I tried what i thought was everything. (i often try choke and no choke, fuel is also on and sidestand always up.) Then after sitting for 5 minutes trying a gear 2 roll start not working, then i put it in neutral and it fired up fine!)

    Thank you for reading the above which is very long. The only things that is different this week, is that I filled up a few days ago on 95 octane instead of standard unleaded petrol which is what I normally use (was accident).

    If anyone has any suggestions they will be much appreciated!



    Kind regards,
    Troy Bryden
     
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  2. Could be the carbs? When was the last time they were cleaned?
    Spark plugs potentially but I don't see how it would sometimes start sometimes not, still worth a look.
    Air/Fuel filters too.
     
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  3. Thank you for replying Clay, I have only had the bike for about 4 months, I am a new rider so have not done the above. I will google how to clean the carbs :)

    Further suggestions are more than welcome!
     
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  4. I just moved my bike from front yard to garage, i put it on neutral and it started up as EASY as it ever has straight away....... :S it was last ridden almost 2 hours ago. It dirty carbs something that could cause such an intermittent issue?
     
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  5. The first thing you need to do is make sure the battery is charging. For this you will need a multi-meter. These things are cheap these days and available from "Repco" or even k-mart.

    Now a 12v battery is not actually 12v. When nearly flat it will be about 11.8V. When fully charged it will be about 12.7V at reast.

    When the alternator is charging it should be about 14+V.

    So put the voltmeter across the terminal at rest and then when the bike is running.

    This will tell you what the charging system is doing.

    If that is not the problem, then you need to move on to spark and then fuel.
     
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  6. Yeah just checked with the multimeter, off, the battery was 12.7v, on it was 14+..........stragely my old battery off was just over 13volts off. I bought this battery new last night ( forgot to mention). Im fairly sure its not fuel........because once running the bike is fine. That means fuel is okay right? Im not sure where the sparkplugs are, but i will try to find out :)

    So carbs and sparkplugs are on my list!
     
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  7. Yes if you get float needles not sitting properly then the bike can become flooded when left, but be running ok normally if the dirt on the seat is small enough.

    The fact that's it's running ok once started means it's unlikely to be spark, but stranger things have hapened.
     
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  8. I agree with iBast about the spark plugs, but if they are old and potentially dodgy they might only spark some times, as said, stranger things have happened.

    Cleaning the carbs can be quite a tough process if you don't have much mechanical knowledge so be sure to research up what you need and need to do before cracking them open.

    It wouldn't surprise me if this fixed your issue, but it wouldn't surprise me if it didn't either.

    What I would do is check/replace the spark plugs because then you can rule out electrical problems (I think) and spark problems. Then there is just Fuel and Air which most problems would come through the filters or carbs. (Hence why I think its a carb issue)

    I am, however, not exactly a mechanic so this is all guesswork, weather you want to give it a go or not is up to you.
     
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  9. Replace the spark plugs and air filter first.

    Strange that it runs ok once started, though.

    Tell us where you are, maybe one of the more experienced riders can help.
     
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  10. I have serviced these heaps when I was doing it many years ago on the side for friends and friends of friends. The plugs are really easy to change so I would try that first. Most new riders don't keep the revs up high enough on this model and the plugs are usually as black as the ace of spades. Don't buy the plugs first. remove them and have a look at the colour. I am predicting that they are black, oily and chockers with carbon build up. If they are it means that you're not keeping the revs up. Atypically they are white which means that the bike is running lean and a different rated plug is required. Remember too that your 1991 CBR250RR was plated in Australia and it was flying around in Japan in the 80's before it arrived in Oz. Most new riders, ride the bike around at about 3 to 4 thousand revs. This bike needs to be ridden at a minimum of 5 to 8 thousand in normal situations and every now and then get it up over the 10+. This will keep your plugs free of gunk and it will be like a different bike. Try not to rev it in neutral but when it is under load eg when your riding. You don't need to ride faster just ride 1 gear down from what you are used to. I'm guessing that you ride around in 4th at around 60 to 70klm/h. Try 2nd or 3rd instead. Usually you don't even need to clean out the carbies. Once you change your plugs and ride it like this, it will usually clean them out anyway. Chunks of carbon etc will just fly out. Oil and oil filter change won't hurt either. If this doesn't fix the problem (I'd be surprised) then it could be the regulator rectifier. This is something that charges your battery while it is running at a faster than idle. Remember that if you don't have the correct tools including; Spark Plug remover, Oil Filter tools, correct grade oil, torque wrench etc, then get a professional to complete the work. Good luck! Paul HART
     
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  11. Thanks a lot guys, the info you are supplying me with is very interesting and helpful for my knowledge. And thanks Paul I assimilated your advice into how I will ride my bike from now!

    To update you guys:
    I called my uncle (an experienced rider but no mechanic) and he suggested that this was a tuneup issue that only a mechanic can really fix or someone who knows what they are doing such as the timing of the sparks or something........i told him all the intricate details.
    HOWEVER
    The last 4 times I have ridden the bike it has started up 100% perfectly. Perhaps this is the nature of the intermittent problem. The only thing that I have done differently is that I have made an effort to turn the fuel tank off when im not riding......over the last few weeks, I have been accidently leaving the fuel tank on most of the time including over night ( late nights, bad habits).

    Could leaving the fuel tank/tap on, lead to my inconsistent troubles starting the bike??

    p.s I still plan to do the above as told, am going to buy tools for the fairings ect today! :) (and i live in glen waverley)
     
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  12. I don't know much about how the fuel system works on those bikes, but could this potentially be flooding it?
     
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  13. Yes. Without turning the tap off you are relying on the float needles to stop fuel getting into the cylinders. These are an imperfect seal at best.

    I am a little suprised it has an off position on the tap. Most "modern" bikes use a vacuum tap that doesn't allow fuel to flow if the engine isn't running or the tap isn't in the prime position.

    To be honest I missed the fact the thing was a Pirate 250. These things are getting old now and are notoriously sensitive to tune maintenance. It seems every winter we get a rash of troubles with Pirate 250 owners.

    If there is an off position, get in the habit of using it. Seems like it may solve your immediate problem, but getting the carbies cleaned and balanced will make your life easier int he long run.
     
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  14. Unfortunately, the bike was running well for about 4 days, as I was using the fuel tap very strictly, however, after that, it made no difference and the old problems came back and did not go away :(

    I have taken my bike apart, removed all fairings and fuel tank etc and looking at what to do. However, I am only 19 years old and this is my first vehicle.
     
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  15. OK seems like you might not be mechanically confident. Suggest phoning a friend, after you get a copy of the manual, or just taking it to a mechanic.

    In the meantime for starting try this. Whilst starter button, slowly wind open the throttle.

    If you want to venture mechanically into the bike, try pulling the tap apart. There will be a couple of gaskets, a diaphragm, a spring, plunger, an o-ring and not much else in here. pay carful attention as you pull it apart. clean it an put it back together. don't force any gaskets.
     
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  16. Hi Mate
    Did you change the plugs, oil and oil filter?
     
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  17. Ibast, sounds like a good task and some good learning, Ill definitely get onto that!

    Paulhart, I changed the oil, but not the filter ( didn't have one on me at the time, and didn't realise the filter was so easy to change until I had it in my hand) and for the plugs I changed one ( it was in good condition, rather wet though.....with petrol im guessing? although it was a orangish tinge to the liquid)

    However, the last 3 plugs are very hard to get to which is partly why I removed the fuel tank for more access, and now am going to change once I borrow the right tool from my friend as my ratchet didn't have a rubber insert.

    Although im cleaning little things, I have been trolling forums for last 2 days straight and I havn't found anything to match my symptoms.....so I really do welcome further suggestions!
     
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  18. Paulhart, I changed the oil, but not the filter ( didn't have one on me at the time, and didn't realise the filter was so easy to change until I had it in my hand) and for the plugs I changed one ( it was in good condition, rather wet though.....with petrol im guessing? although it was a orangish tinge to the liquid)

    However, the last 3 plugs are very hard to get to which is partly why I removed the fuel tank for more access, and now am going to change once I borrow the right tool from my friend as my ratchet didn't have a rubber insert.

    Although im cleaning little things, I have been trolling forums for last 2 days straight and I havn't found anything to match my symptoms.....so I really do welcome further suggestions![/quote]

    Hi Troy, you probably realise that you have only completed bits. Fixing your bike is about trouble shooting a specific problem. The 1 spark plug might look ok but how big is the gap? It's like changing 1 tyre on a car when you have 3 other flat ones. Orange could mean a mixture of fuel and oil. Actually pretty common on the CBR250RR's that I have seen. If the inside of the pipe at the back is black. It is running rich, white is lean and inbetween is usually good. Changing the oil was ok but not changing the filter is like changing the water in pond laced with mud. Let us know how you go after you change the oil, oil filter and all of the plugs. Go to this free download link click download (11mb) and it gives you the plus 400 page manual for your bike. Section 25/2 tells you the spark plug type and gap. Section 25/3 tells you the torque required for the spark.
    I will say again. If you don't have the tools or the time give it to a licensed bike mechanic.

    https://rapidshare.com/#!download|9...|0|1|referer-3121B8D23593D2540F150717EAC30333
     
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  19. After days, I have finally changed the spark plugs and gapped them according to the manuel (0.08-0.09). The old plugs looked like they were not gapped.

    It didnt fix the problem. this I did notice however, is that when I put fuel directly into the carbs, it started up very nicely straight away which usually doesn't happen on the first time with my problem, but would be normal to the intermittent nature if i had already ridden.

    Another intersting thing is that i found some fouled or off fuel in the air filter plastic compartment. there was a reasonable amount and i cleaned it off, however I have the feeling the fuel is not properly getting to the motor....... because the starter cranks, but there is no petrol to rev....when i cant start. and when it does start after turning the bike off a few times and trying again its like it gets a little bit of gas when i give some throttle and when i continue to rev again its like im catching it and throttle begins to get a reaction and my bike starts!

    A note: since changing the spark plugs.......i feel like my throttle is less responsive....however when the petrol tap was off and i ran out of fuel......it seemed to take atleast 4 times or more longer for me to realise that the engine was running out of fuel and for it to finnaly stop after fluttering aroudn for a while. before it was much more sudden that i would run out of fuel and the bike would stop (almost like power strugglign and then going straight off......is this normal?

    You have all been very helpful. I am going to take it to the mechanic and i will post back what happens so that everyone can learn.......however I fear he wants to just rip me off as he wouldn't let me tell him all the symptoms he a bit pushy for me getting down there so he could 'hear' it and see it..........but more likely so he can charge me :( .
     
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  20. ALSO- im not sure if this has anythign to do with orginal problem or my spark plug change. But I am finding it harder to idle............it sortof just dies........but if the bike is REALLY warmed up, then it appears to be a lot better if not perfect :)

    thankyou!
     
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