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1987 Yamaha SRX 250 Project

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  • 1987 Yamaha SRX 250 Project

    So.. after not riding for about 40 years (OMG) I decided I needed a little project to get back into it... so on a local FB Buy Swap Sell site I managed to pick up a little Yamaha SRX 250.
    The previous owner was pretty vague about what was wrong with it other than he thought it needed the carby's cleaned and maybe the cam chain... oh.. plus battery, tyres, paint etc etc...lol
    Yes.. she is rough... but I like the look and I have a pretty good idea of what I want to do with it...
    This was when I picked it up...



    One night after work I thought I would hook up my booster set and see if I could kick it over at least... but nothing... so I connected straight up to the output side of the starter solenoid and switched the booster on and off.. and it seemed locked solid...maybe it was seized and he just didn't tell me..
    So I quickly pop the small cover off the Magneto side and try to turn it over manually... all I got was about 20 degrees movement on the socket... which indicated it at least wasn't seized.

    Today I decided to pull the covers of the crankcase to see what the problem was... and it is an interesting one...

    What has happened is one of the bolts holding the sprocket onto the exhaust cam has come out... the sprocket has moved and broken the tab where the other bolt was and then dropped into the crankcase... it looks like it stopped in a real hurry... although there is next to no major damage... although I haven't pulled the head of it yet.

    So I took off all the clutch etc and managed to get the old sprocket out as well as the cam chain... surprisingly.. the cam chain is pretty good, the sprocket has a few shape nicks on the surface but non where the chain runs... the biggest issue for me is the exhaust camshaft needs replacing and the oil tube (goes from the crankcase into the barrel between the chain) was cut in 2.

    So the search begins for those items before I do anything else... because if I can't get them... its scrap time I think...
    I do hope I can source them... I have a lead on a dead FZR250 3LN and I can use the front forks, twin disc setup and the swing arm / rear disc setup as well as the wheels... which will be a good basis for the look I want.

    If anyone has any ideas on the Oil Tube let me know... I am pretty sure I can get cams.. or even a head...

    Here are some more pics...



    Here you can just see the broken section on the exhaust cam...




    Loosely reassembled some parts so I could turn the engine over... its definitely not seized...



    This is the (now) 2 piece oil tube



    It did a number on the rear chain guide too...



    Anyway.. hopefully good news will follow during the week re parts and this will progress along.

  • #2
    munted engine..

    Just out of curiosity..( under $50 for the bike?)

    Don't answer if ya don't wish...too.
    " Imagination is the seed of life..."

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    • #3
      Reckon you could make one of those oil tubes, or have a machinist make one.
      Click Link for My Bikes:

      Aprilia RS250
      1985 GSXR750 "Slabbie"

      Comment


      • #4
        ^^ yeh ..^^^^

        .no offence ...eh?

        Oil tube is oil tube...ali ..do? google tube size/dimension .....should be easy as...

        Yah got bent valves n stuff ..too...:-(
        " Imagination is the seed of life..."

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        • #5
          I haven't pulled the head off yet... waiting till I find a camshaft etc... no point pulling it done any further than I have to if I can't get the bits.
          The oil tube is available as an OEM part apparently... so that is a plus.
          Other than the cam chain issue the internals look to be pretty clean... there is no sludge at all... and the oil wasn't burnt etc.
          It will most likely need rings and a hone... plus re-seating the valves (as long as they are not bent) but that is all easy stuff for me.

          Google didn't help me much with the oil tube length... size I can get as I have 2 pieces that are good... lol

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          • #6
            Soz Andy..

            .googs only if size of tube known..any material you would need to cut length..

            ..I tend to gloss over the details when replying...mate

            as in life ...
            " Imagination is the seed of life..."

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            • #7
              I had one for my first bike. Keen to see the end result.

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              • #8
                After much checking last night and into the early hours I might have a solution... TT350 top end (barrel, piston, head etc) can be fitted to the 250... The Oil feed for the head is external which is no problem... Use a 350 clutch cover with kick starter hole blanked and blank the Oil feed hole in the crankcase...
                The crankcase needs to be machined to take the larger barrel but that won't be an issue.... Now I just have to find a donor TT350 top end...lol

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                • #9
                  Now we're talking
                  Click Link for My Bikes:

                  Aprilia RS250
                  1985 GSXR750 "Slabbie"

                  Comment


                  • #10
                    Hey Andy...

                    shitty barrel ( needs bore...even bigger piston ;-)

                    and head on Evilbay..$200 seperate ads + freight.. eh??

                    Cases n shit too... you keen to upgrade to and gearbox..?
                    " Imagination is the seed of life..."

                    Comment


                    • #11
                      I might have a lead on a complete engine... no worries if it needs boring, preferable if it only needs a hone and rings but I will see... at least I will get the Clutch cover and clutch as well that way.
                      Waiting on a price..
                      Gearbox on mine looks in pretty good shape to be honest... hopefully it will all come together this week and I can make some definitive plans...

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                      • #12
                        A bit of an update.... people want STUPID money for XT / TT350 barrel and head.... so that ended up out of the question.
                        I did manage to source a really good condition exhaust cam and sprocket... cam chain guide and oil tube... so the next step is to rip the head off it tomorrow and see if there are any bent valves and what the bore etc is like.

                        Other good news is that the donor for the revised front and rear brakes... (dual front discs and rear disc) FZR250 3LN will be here tonight...

                        Comment


                        • #13
                          Hi interested in your project,same deal bought a srx250 currently stripped down frame wheels and swinger powder coated parts are hard to find over here ,got some parts from auction sites in Japan new and used,currently looking for a bellypan ?,wondering on the fzr250 front end is it a straight swap might go down that route as my forks are trash😀

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                          • #14
                            Originally posted by Baz69 View Post
                            Hi interested in your project,same deal bought a srx250 currently stripped down frame wheels and swinger powder coated parts are hard to find over here ,got some parts from auction sites in Japan new and used,currently looking for a bellypan ?,wondering on the fzr250 front end is it a straight swap might go down that route as my forks are trash
                            Don't worry... parts are hard to get here as well.. and they are not cheap either.
                            I haven't even pulled the front end of the FZR yet so I have no idea of how easy it is to fit... I will get to that eventually. I want to get the engine sorted first... and on that note I now need 2 inlet valves... yep... they are bent. Based on the condition of the combustion chamber the top end must have been done... and when they reassembled it they must have missed one bolt on the exhaust cam sprocket... which isn't enough... it let go causing the damage... including a coulee of bent valves...
                            The good news is that the head certainly ISNT cracked and the bore looks good with little wear.
                            While I have it down I may as well throw a set of rings into it... rego the head and she should be all set to go... fingers crossed.

                            Comment


                            • #15
                              Srx250

                              Originally posted by Andych View Post
                              Don't worry... parts are hard to get here as well.. and they are not cheap either.
                              I haven't even pulled the front end of the FZR yet so I have no idea of how easy it is to fit... I will get to that eventually. I want to get the engine sorted first... and on that note I now need 2 inlet valves... yep... they are bent. Based on the condition of the combustion chamber the top end must have been done... and when they reassembled it they must have missed one bolt on the exhaust cam sprocket... which isn't enough... it let go causing the damage... including a coulee of bent valves...
                              The good news is that the head certainly ISNT cracked and the bore looks good with little wear.
                              While I have it down I may as well throw a set of rings into it... rego the head and she should be all set to go... fingers crossed.
                              Yeah I am lucky engine is good ,I got lots of bits new and used from Japan auction sites much cheaper than Yamaha dealers ,if your looking for parts I used Jauce auction Japan,but be careful there are fees to be paid and here customs get you but still works out cheaper

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