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Project GSX250 restoration

Discussion in 'Your 250cc Projects' started by SwarleyAUS, Mar 21, 2017.

  1. SwarleyAUS

    SwarleyAUS Well-Known Member

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    Hi guys,

    As mentioned in my introduction thread, I'm restoring - or more modestly, just trying to get running again - a GSX250. Bought with a flat battery so not sure of the running state, electrics, etc, etc.

    Have already got a couple questions I was hoping to get some help answering from simply taking the bike apart for cleaning:

    - Have these two wires, W/G & W/R that are not connected to anything. My reading suggests they should go to genny & rec/reg but I don't see any wires coming from those components to mate these wires to. Help?

    17407945_10212668935617050_1131998148_o.jpg

    - Also I can't find any info in the manual about this secondary air filter guard, the black one. It was bent in an arch shape underneath the foam filter, under the top, white guard. I thought that can't be right and moved it... not sure how it's supposed to sit.

    17379875_10212668969817905_621501178_o.jpg

    - Finally - and I think I know the answer to this one - how critical is it that I check valve clearances before trying to start her up? Don't really want to go opening up the engine if I don't have to.

    Cheers,

    Taylor
     
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  2. Murdo

    Murdo The Good Doctor Staff Member Contributing Member Ride and Events Crew

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    The valves may be ok, but it ALWAYS pays to check the clearances as sometimes bad valve clearances are what causes a bike to stop and the owner to sell it (see my VT250 thread on this very cause).
    Sorry I cannot help you with the wiring, only suggest to study several different diagrams as sometimes they give more information.
     
  3. Johnny

    Johnny Well-Known Member Premium Member

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    I am not sure about those wires, but definitely read this, that should explain some: http://thegsresources.com/statorpapers.php
    Also here is the wiring diagram from the Haynes manual:
    elektriskeem.jpg

    As for the air filter, the original foam element had some strong base which isn't part of those aftermarket cut-yourself-a-filter elements, so instead of that base, somebody has used a second plastic holder as a base. That plastic holder is meant to go on top of that foam actually. But I don't have two of those nor the original type foam element neither, I just use that holder as a base and put the foam on top of that.
    But anyway, here is the picture depicting the original configuration:
    air cleaner.jpg
     
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  4. SwarleyAUS

    SwarleyAUS Well-Known Member

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    Thanks guys,

    Would turning over the engine (by hand at the crankshaft) and ensuring there is no resistance throughout the cycle verify that the valves clearances are ok?

    I cannot read that wiring diagram whatsoever but I have the haynes manual and some other references on the web that are better. Problem is I can't find any disconnected wires coming from the genny or rec/reg that they could connect to. Will have to investigate further unless someone can show me them connected to something on their bike.

    The air filter had two plastic grids, one black and one white, the black one under the foam, the white one atop the foam. The black one doesn't fit very well. Ok so I can probably remove it provided the foam filter doesn't flap around. Cheers.
     
  5. Johnny

    Johnny Well-Known Member Premium Member

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    I think that grid will stay a bit warped, I remember I had to toy with it a bit myself when I checked that last time.
    The wires though, could have something to do with the fact that these bikes had one of the three phases from the stator wired through the front light in the factory setting. It was a flaw and it is recommended to wire all three phases to the regulator. Maybe somebody fixed that and those wires are the left-over? The whole thing is described in that weblink I posted though, definitely read that.
     
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  6. SwarleyAUS

    SwarleyAUS Well-Known Member

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    Cheers Johnny I think I've got the black grid in place now.

    I *think* the rec/reg may not be original. 3 yellow wires come out of the engine above the tranny and go to the reg/rec. Another oddity though, following that Black wire out of the rec/reg, is that it also doesn't go anywhere - see the second image. Orange and Black go in to the connector, only Orange comes out though? o_O The Orange wire comes out of the box below the Igniter box - Signal Generator I think it is?

    Also tried turning the motor over at the crankshaft and hit a bit of resistance, so I think I definitely need to check timing is correct and valve clearance is ok. Agreed?
     

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  7. Murdo

    Murdo The Good Doctor Staff Member Contributing Member Ride and Events Crew

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    Agreed. Take the plugs out and see what they look like.
     
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  8. SwarleyAUS

    SwarleyAUS Well-Known Member

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    Rightio Murdo. Am I expecting to see the plugs bent or something? It'd be the valves hitting the pistons though right?
     
  9. Johnny

    Johnny Well-Known Member Premium Member

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    When turning the engine over, it is important to note that you do it by the large 19mm hex, and not by that small bolt ahead of it. Also that you turn the engine only clockwards.
    Now if you turn the engine, you feel resistance, and it is not even during the whole turn, but it doesn't take great strengh to turn that engine over, even with the plugs intact. If you can turn the engine over, I'd get a good charged battery, a car battery would do for now, make sure that the wires are connected properly (no loose grounds somewhere!) and see if you have spark and if you have, then ignite it.

    On the other hand, checking everything beforehand is not a bad idea at all, it is actually a very good idea, if you feel confident to do it and have the tools.

    Checking the spark plugs can give you some idea about the condition of the engine, check these pics for reference:
    spark_plugs1.jpg spark_plugs2.jpg
     
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  10. maelstrom

    maelstrom LiteTek Staff Member Premium Member 250cc Vendor Contributing Member

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  11. SwarleyAUS

    SwarleyAUS Well-Known Member

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    Thanks guys, I'm gonna check the valve timing is right, valve clearance is ok, condition of the plugs, etc on the weekend. Fingers crossed the resistance is caused by none of these but I'll try to muddle through adjusting these things if need be. I don't want to open the engine if I don't have to, but I also don't want to go damaging the engine trying to start it up preemptively.
     
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  12. Murdo

    Murdo The Good Doctor Staff Member Contributing Member Ride and Events Crew

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    I was thinking more along the lines of the plugs being rusty (water in the cylinders) or if it has swallowed a loose screw or something.
     
  13. SwarleyAUS

    SwarleyAUS Well-Known Member

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    Ah ok! There's a lot of petrol in the sump, hopefully there's no water though. Actually in regards to cycling the engine, with the plugsin, I'd expect to experience some resistance wouldn't I? Due to compression? If so maybe I'm in luck any the timing is ok, I'll still check though.
     
  14. GreyImport

    GreyImport Administrator Staff Member The Chief Contributing Member

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    If theres fuel in the sump then take out the plugs and carbys off and drain the sump

    turn over the motor by hand to get all the excess out of the cylinders and let it drain and sit for a day or too for the fuel to evaporate.

    And yes with plugs in there should be compression resistance
     
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  15. SwarleyAUS

    SwarleyAUS Well-Known Member

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    Ok cool, yep got a few litres of oil to do 1 or 2 changes as necessary!
     
  16. Johnny

    Johnny Well-Known Member Premium Member

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    And the fuel got into the sump as a result of a faulty petcock I suppose?
     
  17. SwarleyAUS

    SwarleyAUS Well-Known Member

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    I don't think so, the vacuum seal was stuck closed in the petcock. Probably just residual fuel from the carbs leaking in.
     
  18. SwarleyAUS

    SwarleyAUS Well-Known Member

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    Plugs look good, dry, sooty, gap ok.


    IMG20170323185743.jpg
     
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  19. SwarleyAUS

    SwarleyAUS Well-Known Member

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    Haha whoops, bike was in gear, that's why there was resistance! Even if I wanted to check valve timing, how do I align the crank? No 'T' markings on it like I expected...

    IMG20170324193938.jpg
     
  20. Linkin

    Linkin The Mechanic Premium Member Contributing Member Dirty Wheel Club

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    Find TDC on compression stroke - sparkplug out on #1 cylinder, check that the piston is up top, cam lobes for that cylinder should be pointing up to their respective places (intake lobes facing up towards the intake side, exhaust valves facing up towards the exhaust side). Then you can mark with whiteout where everything is.
     
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