Suzuki GT250 Cafe Racer

Discussion in 'Some Assembly Required' started by Damian_74, May 9, 2019.

  1. Damian_74

    Damian_74 Been here awhile

    Joined:
    Feb 4, 2008
    Oddometer:
    720
    Location:
    Brisbane, Australia
    Had a mid life crisis. The first bike I owned was a GT250 and was born in 1974 so w hen I saw a 1974 GT250L for sale I had to have it. The bloke that I bought it off has a home resto / repair business for old Jap bikes and put this bike together from bits and pieces.
    It's overall a nice bike but as it was done to a price it has it shortcomings.
    I originally had intentions of taking the angle grinder to the 74L but it was too nice a bike to hack up. After I finish this project I might attack it and do a proper job.

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    So in the mean time I went and bought this!!!!!!!!!!!!1976 GT250B
    What the hell was I thinking??????

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    It needs everything.

    Not entirely which way this project will end up - definitely leaning to the Cafe style but not committed as yet.

    This is going to take a while!
    #1
  2. Damian_74

    Damian_74 Been here awhile

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    Going to start with the engine until I decide what I'm doing with the rest of it - it was locked up and originally suspected the crank - got a surprise when I split the case. The bike had been sitting in the weather with no gearbox filler cap and it had partially filled with water - definitely didn't expect that.

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    There isn't too much to salvage in the gearbox bit the crankshaft is in fairly good condition (obviously needs a rebuild but turns freely).
    Supplied with the bike were a set of barrels and a head that had been Vapour-blasted. The bores were 0.5mm over-size - and almost usable and was seriously considering just throwing a set of pistons in them - more on that later.

    The cases were as expected for a 40 year old 2 stroke - hours spent with de-greaser, phosphoric acid and a petrol powered pressure cleaner and I found the cases.

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    #2
  3. shovelstrokeed

    shovelstrokeed Long timer

    Joined:
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    6South Florida
    Please move this to Some Assembly Required, where it belongs
    #3
  4. anotherguy

    anotherguy Long timer

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    Jun 18, 2009
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    the hills
    And get offa the lawn while yer at it.
    #4
    more koolaid likes this.
  5. Effisland

    Effisland Long timer

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    BC
    how do you still find bikes like that? Out in the country?
    #5
  6. neil w

    neil w Been here awhile

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    Jan 13, 2013
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    245
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    Northumberland
    It's crying out for sympathetic restoration to a create a typical mid 70's bike, Akront rims, set of Allspeed pipes, ace bars, Guillari 2:4 style seat and a mild porting job
    #6
  7. Damian_74

    Damian_74 Been here awhile

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    The most likely path - but you forgot the Higgspeed expansion chambers!
    #7
  8. Damian_74

    Damian_74 Been here awhile

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    Location:
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    Thought that I was on a winner.....found a 74RAM engine in Tassie that had had had been overhauled and partially assembled. Advertiser (who turned out to be a Mate of a Mate) had "rebuilt" the crank, New OEM 1.0mm OS pistons gasket set, all casings vapour blasted. $1000 delivered to Brisbane - how could I go wrong!

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    Well..................I had asked specifically about the crank rebuild when we were negotiating the deal and specifically asked about the crank seals but something was lost in the phone call.

    WHY WOULD YOU GO THE THE TROUBLE OF REPLACING THE MAIN BEARINGS, CONRODS AND PINS AND NOT REPLACE THE SEALS!!!!!

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    The seller didn't intentionally miss-lead me, was going off poor advice from others. Emailed the bloke and he agreed to refund $300 towards the crank rebuild.

    Now what to do - re-build the 74 engine or use the parts in the 76 (correct for the frame)?
    #8
  9. Damian_74

    Damian_74 Been here awhile

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    The 74L and the 76B engines have a different crank design - 3 vs 4 bearing - the latter more robust. My biggest unknown was the gearbox and clutch.

    When they went to the 4 bearing crank the gearing was also slightly changed.

    K,L,M 1st 2.333, 2nd 1.50, 3rd 1.105, 4th 0.905, 5th 0.782 and 6th 0.708:1.
    A,B,C 1st 2.333, 2nd 1.32, 3rd 1.050, 4th 0.905, 5th 0.782 and 6th 0.708:1.

    Had a fit up of all the gearbox and clutch internals of the 74L to the 76B's cases, it all appears to fit - so it is the 76 engine it will be!

    The bearings for the 76 are now obsolete. There are NOS on eBay for silly prices, and then there is the concern of how well the bearings have been stored for the last 30 years and how long an ancient rubber seal will last????

    The other option is the eBay seller "cruzinimage". Complete crank and bearing seal kits for under $200 AUD shipped to Australia and about the same for the rod kit. Obviously Chinese pattern parts.....quality unknown!

    Has anyone had any dealings with cruzinimage?
    #9
  10. Damian_74

    Damian_74 Been here awhile

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    Just got the cases back from the Vapour Blaster - they look like they just came out of the die! Couldn't be happier!

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    #10
  11. Damian_74

    Damian_74 Been here awhile

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    I didn't expect the hurdles to jump up at this early stage. I work away month at a time hence ordered the crankshaft parts so that they would be sitting ready for when I get home - thought it was all sorted.......... :cry:

    Ordered form Cruzinimage via eBay.

    It appears that they have sent me the parts for a GT250 X7.......not really the same engine!
    Different mains (they completely failed to send any seals) and different length big end pins (need 57mm pins rather than the 50mm).

    At least they are talking to me on eBay and trying to sort the problem.....see how this works out!


    From what I have researched.........can anyone in the know please confirm that these are the correct crank parts for a GT250A (4 bearing) crank.

    2 pc. Suzuki # 09262-25009, Koyo # 83197-9, Size 25x65 x17
    2 pc. Suzuki # 09269-25005, Koyo # 83190-9TC3 NR, Size 25x65x17/14

    1 pc. Suzuki # 09283-25019 crankshaft oil seal 25x65 x12
    2 pc. Suzuki # 09289-33006 crankshaft oil seal 32.3x65x10

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    #11
  12. Pezz_gs

    Pezz_gs Cant ride for crap

    Joined:
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    Hey @Damian_74

    Cruzinimage are usually pretty good. . . .

    Ian Lovell at Servalloy in Mundoolun makes custom expansion chambers, swingarms alloy tanks. . . . you name it.
    He can build a set of tuned chambers and closer to the mark then the one chamber design fits all.
    He has been around racing two strokes for years. Would be a good source of information too.

    PM if you want his mobile??

    Have you checked here?
    https://www.cmsnl.com/suzuki-gt250_model13776/
    #12
    Damian_74 likes this.
  13. Damian_74

    Damian_74 Been here awhile

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    Hi Pezz,

    I've had a look on cmsnl - they have some but but not all of the parts that I want. Unfortunately they think they are holding the crown jewels and priced to match, and that is before they add the freight!
    #13
  14. Damian_74

    Damian_74 Been here awhile

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    It seems that my engine overhaul has stalled for a bit till I sort the bearing and seal issue - so in an effort to push the project along I have started on all the components. Hadn't intended to strip the rest of the bike at this stage but with all the delays I wanted to at least feel like I was making some progress.

    Have a selection of different cutting and polishing wheels and started with the side cases and wheel hubs.
    WHAT A PIG OF A JOB but at least the effort pays off.

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    But makes a hell of a mess.

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    #14
  15. kruzuki

    kruzuki Gear in the Machine

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    Toronto, ON
    I'm interested in this build.
    I had a '74 T350 a long time ago. Didn't keep it long, just fixed it up to make it roadworthy then sold it & broke even on the restoration costs. Nothing like what you're doing. Good luck!
    #15
  16. Wildebeest90210

    Wildebeest90210 Long timer Supporter

    Joined:
    May 24, 2013
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    2,912
    :lurk:lurk:lurk
    #16
  17. Damian_74

    Damian_74 Been here awhile

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    Brisbane, Australia
    Hare and Forbes are having their "End Of Financial Year Sale"

    Watch this space!

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    #17
    Pezz_gs likes this.
  18. Damian_74

    Damian_74 Been here awhile

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    New Hyd Press - 150mm between the rails - easily big enough to fit a 2 stroke crank!

    I need to make up a few special tools but at 30 ton this will be more than sufficient for a little 250 crank!

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    It is typical Chinese quality - shit welds, sharp edges but when I priced the material and jacks to make my own it was cheaper to buy this one (and a hell of a lot quicker/ easier).

    https://www.machineryhouse.com.au/P1475" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;

    Also a press brake attachment - will bend 4mm x 450mm or 6mm x 300mm

    https://www.machineryhouse.com.au/P450" onclick="window.open(this.href);return false;

    Man can never have too many toys - but he can have a lack of space!
    #18
    JagLite likes this.
  19. Damian_74

    Damian_74 Been here awhile

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    Had a little trip the the local Zinc Platers.

    In anticipation of getting a start on the engine I want all the cylinder studs and bolts plated, took a few other bits along too.

    They turned out well - I had given them all a buff and run a file over all the burrs before hand.

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    #19
  20. Damian_74

    Damian_74 Been here awhile

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    Finally finished the wheel hubs - then spent a couple of hours cleaning the workshop (aluminium polishing isn't my favourite part of any restoration).

    But was more than happy with the result!

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    #20