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New rider, new (old) bike experiences

Discussion in 'New Riders and Riding Tips' at netrider.net.au started by slingy, Aug 23, 2010.

  1. 3 months after doing the test to get my permit, I've finally got myself a bike!
    Picked up a 1997 Kawasaki GPX250 with only 26,000km on it. I don't think the bike has been maintained very well and has hardly been ridden over the last few years.
    My first experience of riding it wasn't too bad. I wasn't quite as rusty as I expected and slipped straight back into feeling like I did at the course. The GPX feels pretty similar to the bike at the course - Yamaha Scorpio, in terms of the feel of the clutch, throttle, brakes and the overall weight.

    I've noticed it's a bit difficult to find time to indicate while changing down gears and preparing for corners and it's also taking longer than it should to remember to turn off the indicator after a turn.


    Apart from all this.. the bike needs a bit of maintenance work..
    I rode it to work the day after I got it, went to leave at the end of the day and the damn bike wouldn't start.
    Came back in the car with some tools and checked it all out.
    Battery ok.
    Fuel level ok.
    Spark ok.
    Fuel supply .... no

    Messed around with the petcock trying to work out how it works.. It needs a vacuum to allow fuel to flow in the "on" and "res" position. This doesn't seem to be happening very reliably until the bike is actually started.
    A little bit of fuel (or start ya bastard) down that vacuum hose to get the bike started, then plug it back into the petcock and everything is alright.

    After pulling the fuel switch apart, it seems that the membrane in the back of the diaphragm is a bit dodgy. Local Kawa dealer wants $48 for a replacement, so I ordered one online for $10. Hopefully it arrives today so I can stop having to pull the hose and carry around a can of start ya bastard.

    The bike is also running a bit badly. Stalling a bit while cold. When rolling to a stop (the last little bit when i'm going too slow for second gear) with the clutch pulled in the bike often stalls. Kinda weird, because it sits in idle fine.. the problem is only when it's moving.!! Anyway, I figure it's just in need of a good service and overall check-up.



    Today or tomorrow I'll be heading over to my dad's workshop - he's an auto mechanic, to service the bike. Between the two of us, I'm confident of us being able to service the bike properly and get it running better.
    It will be a good experience and help me to learn a bit more about the bike. I believe the best way to learn is to just jump in there and do it!!
     
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  2. Well, on Tuesday I changed the oil and oil filter, cleaned the air filter, put in new spark plugs, changed the coolant, changed the brake fluid, cleaned and lubed the chain, lubed the cables (throttle is still sticking a little bit though).

    Also tried to sync the carbies by ear... it's running better, but still not great.

    My petcock repair kit arrived yesterday, so I've got to install that.
    Also going to pull the carbies and mess around with mixture - i reckon it's running a bit rich.. and also gotta adjust the valves.

    After that.. I'm really hoping it runs a bit better..


    Problem at the moment is that the bike isn't starting without adding "start ya bastard", once it does start, the choke needs to stay on for what feels like forever, even after the bike should be warm enough..

    The idle is really erratic and needs to sit around 3K RPM just to keep the bike running. It will often stall when rolling to a stop with the clutch in.
    Idle also seems to constantly be adjusting itself higher.. after a half hour ride it will finish up wanting to idle at around 5-6K RPM.

    While running it sometimes gets a bit jumpy. Cruising at constant throttle it has a tendency to jump forward and then die back.
    :-({|=

    Anyway, if anyone has any advice on other possible causes and solutions for these problems please let me know!!!
     
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  3. I'd recommend waiting until you've fixed the vacuum tap and see what difference that makes before tearing too far into the carbs. A faulty vac tap or hose could easily cause an air leak that would cause all sorts of closed throttle running and starting problems.
     
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  4. Cheers. patching up the petcock will definitely be the first job.. Plus it's the easiest.
     
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  5. Sounds like you're getting her up to scratch pretty well there, slingy.

    On carbies, you will want to try a fresh airfilter before rejetting or messing around to suit the old one. If it is a paper element type I would bin it and buy a Unifilter item - it'll give better filtration, better flow, and is also washable & reusable. They should stock one to suit the GPX - they have items to suit my '84 GSX-1100 haha...

    Cheers - boingk
     
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  6. Yeah, the airfilter was the sponge type. Took it out, gave it a good clean with carby cleaner then some water and soap. Oiled it and put it back in.
    It's in pretty bad shape but seems servicable enough until I get a new one..

    Right now the bike is out in the weather (but under a cover). Need to get the damn car I'm fixing up out of the garage.. Unfortunately that's going to have to wait until I get some days off... It's disappointing having wait to get it up to scratch enough to enjoy riding it.
     
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  7. Tell me about it. You definitely appreciate it more when its been put on the road by your own efforts, though. All my bikes to date have been this way, except for the DRZ which was kindly loaned while I was on L's and the GS850 which never got registered. The other three were built up from varying states of disrepair, and I wouldn't have it any other way!

    Nothing wrong with a bike cover, it'll save it from the worst of the elements and help avoid the bike getting UV damaged...funny to see the odd bike getting around thats fine on one side and totally f***ed on the other haha.

    Cheers - boingk
     
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  8. Changed the petcock diaphragm yesterday in the fuel switch. It has made an amazing difference. The bike starts on its own now =D>
    Still running a little rough, a bit jumpy. Need to adjust the idle again too. No big job, just need to take the time.
     
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  9. yesterday i finally had time to adjust the valves (surprisingly tricky job) and cleaned the carby. The fuel out of the the bowls looked bad, but not too bad.
    Since this, the bike now starts without the choke! and seems to be capable of idling a bit lower.
    Noticed there is a little bit of fuel leaking out the bottom of the carby just after I turn the ignition off... i think i didn't tighten everything as much as i should have.. the screws holding the bottom of the carby on are a biatch - they aren;t normal phillips head, they're a bit more shallow and really soft, so it's hard not to strip them. I had such a hard time taking them out that I didn't do them up too tight when putting them back in. I'll see if I can tighten them a bit more without removing the carbs again... Then it's time to synch the carbs and away we go!
     
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  10. Slingy, Good to see you're getting your hands dirty tinkering and fixing your bike. Well done mate.
     
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  11. Time to see about getting a pack of stainless M5 (probably) capscrews from SuperCrap or similar. Too expensive in onesy-twosey quantities, but you only need eight of 'em.
     
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  12. I reckon this could definitely be the way to go.. I think there is something wrong with the carbies since I cleaned them, so I'll be pulling them out again next week (4 days off, woohoo!) and rebuilding them with a couple of repair kits, so I'll replace the screws at the same time.

    After this has been done, and I get the mixture right and synch the carbs, I will have done just about everything I can to get the bike running well.. If it's still konking out when idling low I won't know what else to do. My fingers will be crossed.
     
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