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Thread: Welcome back to me - first bike problem :)

  1. #1
    Join Date
    14th January 2008 - 01:44
    Bike
    1986 GSX400E
    Location
    Auckland
    Posts
    57

    Welcome back to me - first bike problem :)

    Hi all - old member here. Just bought another bike after about 11 years with no road bike

    I'm an engineer so I do enjoy the maintenance slightly more than the riding... so I've picked up a clapped out GSX400E to convert to a cafe style.

    My question is generic about engine troubleshooting:

    The engine isn't running and the seller said, quote: "it started getting harder to start, until finally i could only get it running via crash-start rolling down a hill, then eventually nothing. I did a compression test and was low compression. Pulled head off to investigate and nothing obvious. Gave up."

    So the head and everything was on finger tight and I've re-disassembled and confirmed so far nothing obvious is wrong. I'm also going to remove the cylinder today and check piston rings, and do a water tightness test on the valves.

    My challenge is, I want to get the engine assembled first and get her running so I can isolate all faults and price up the project (for all I know he tested compression wrong and has disassembled the engine for no reason. Might actually be a fuel or ignition issue?!)

    What I don't want is to pay for an entire gasket kit and use it for 5 minutes to reveal noisy gearbox bearings etc, only to disassemble it again.

    1: Would it run OK with the old head gasket for testing?
    2: Should I maybe just gasket-glue the old gaskets for testing?
    3: Should I bite the bullet and pay for a set, knowing I'll disassemble it soon to paint the motor anyway?

    Im leaning towards 2... $20 tube of CRC gasket...

  2. #2
    Join Date
    24th September 2004 - 06:46
    Bike
    '76 CB550 Super Sport
    Location
    On the road to nowhere...
    Posts
    7,414
    These and especially the GSX250s can be prone cracking between the valves. Yeal just for a quick test I see no reason not to use the old head gasket if it isn;t damaged. Did that on my GSX750EX. Don't use gasket material on it's own.

    Stale laquered fuel in the carbs is one thing to watch for on a bike that's been out of commision for a while.

    Reg/Rect units are notorious for going on this era Suzuki and as well alternator windings in some cases.

    What you describe happening to the previous owner could well be just the battery getting so flat it couldn't provide enough spark. This happened twice to me on my cb550 until I replace the rectifirer then later reg and rect with an after market solid state set up.

  3. #3
    Join Date
    14th January 2008 - 01:44
    Bike
    1986 GSX400E
    Location
    Auckland
    Posts
    57
    Quote Originally Posted by Bonez View Post
    These and especially the GSX250s can be prone cracking between the valves. Yeal just for a quick test I see no reason not to use the old head gasket if it isn;t damaged. Did that on my GSX750EX. Don't use gasket material on it's own.

    Stale laquered fuel in the carbs is one thing to watch for on a bike that's been out of commision for a while.

    Reg/Rect units are notorious for going on this era Suzuki and as well alternator windings in some cases.

    What you describe happening to the previous owner could well be just the battery getting so flat it couldn't provide enough spark. This happened twice to me on my cb550 until I replace the rectifirer then later reg and rect with an after market solid state set up.
    Oh thanks thats interesting.

    Scary thought that his compression test might've been low for the same sluggish battery issue ... that'll mean I got a free bike with nothing wrong with it (except it's in pieces )

    I'll be sure to check out the cracking around the valves. Cheers!

    Sent from my SM-G950F using Tapatalk

  4. #4
    Join Date
    22nd October 2002 - 11:00
    Bike
    Sold
    Location
    Coromandel Town
    Posts
    4,407
    Have you got a manual? I've got an soft copy (pdf) manual for a GSX 400 F. There will obviously be differences but a lot of common stuff too. You're welcome to a copy if it's any good to you.

    Cheers,

    Geoff

  5. #5
    Join Date
    25th March 2004 - 17:22
    Bike
    RZ496/Street 765RS/GasGas/ etc etc
    Location
    Wellington. . ok the hutt
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    20,500
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    2
    Petrol test not water.

    Reread Bonez post 3 more times, it is very likely. They killed battery, stator rectifier and then eventually cdi.
    Don't you look at my accountant.
    He's the only one I've got.

  6. #6
    Join Date
    28th May 2006 - 19:35
    Bike
    suzuki
    Location
    lower hutt
    Posts
    7,918
    Quote Originally Posted by F5 Dave View Post
    Petrol test not water.

    Reread Bonez post 3 more times, it is very likely. They killed battery, stator rectifier and then eventually cdi.
    methlyated spirits is less smelly

  7. #7
    Join Date
    24th September 2004 - 06:46
    Bike
    '76 CB550 Super Sport
    Location
    On the road to nowhere...
    Posts
    7,414
    Quote Originally Posted by jellywrestler View Post
    methlyated spirits is less smelly
    Always wondered what was in that hip flask.

  8. #8
    Join Date
    14th January 2008 - 01:44
    Bike
    1986 GSX400E
    Location
    Auckland
    Posts
    57
    Quote Originally Posted by Blackbird View Post
    Have you got a manual? I've got an soft copy (pdf) manual for a GSX 400 F. There will obviously be differences but a lot of common stuff too. You're welcome to a copy if it's any good to you.

    Cheers,

    Geoff
    Thanks for the offer. I picked up a free Manual online for this model very easy.


    Sent from my iPhone using Tapatalk

  9. #9
    Join Date
    1st September 2007 - 21:01
    Bike
    1993 Yamaha FJ 1200
    Location
    Paradise
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    14,126
    Blog Entries
    2
    Push starts and hill starts use no electrical power to get the engine spinning fast enough to light the fire in the cylinder.

    Having said that ... low compression will not help either.

    If you seriously want a reliable runner ... pull the Barrel off and hone the bore ... and put new rings in.

    Top end rebuilds aren't that cheap, but reliability seldom is.

    Get it starting and running before any other work gets done.
    When life throws you a curve ... Lean into it ...

  10. #10
    Join Date
    25th March 2004 - 17:22
    Bike
    RZ496/Street 765RS/GasGas/ etc etc
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    Wellington. . ok the hutt
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    Old GSXR400 ex gf bought wouldn't start. Been sitting ages. Towed it (dangerous if not careful) that got it going. A long thrash using low gears seemingly ungummed the rings .

    Ran fine after that starting good, even dynod better than her other one.
    Don't you look at my accountant.
    He's the only one I've got.

  11. #11
    Join Date
    24th September 2004 - 06:46
    Bike
    '76 CB550 Super Sport
    Location
    On the road to nowhere...
    Posts
    7,414
    Quote Originally Posted by F5 Dave View Post
    Old GSXR400 ex gf bought wouldn't start. Been sitting ages. Towed it (dangerous if not careful) that got it going. A long thrash using low gears seemingly ungummed the rings .
    ..
    Sounds more like off fuel/low speed jet bockage. Generally jappers can sit at least a decade without rings seizing.

  12. #12
    Join Date
    25th March 2004 - 17:22
    Bike
    RZ496/Street 765RS/GasGas/ etc etc
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    Wellington. . ok the hutt
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    Thrashing it wouldn't have cleared blocked jets. But yes have played that game, actually worst case was choke ccts on a similar bike. Needed a 0.4mm drill bit from chole cct down tube and a further one in the float bowls. Very odd carbs.
    Don't you look at my accountant.
    He's the only one I've got.

  13. #13
    Join Date
    14th January 2008 - 01:44
    Bike
    1986 GSX400E
    Location
    Auckland
    Posts
    57
    Quote Originally Posted by Bonez View Post
    These and especially the GSX250s can be prone cracking between the valves. Yeal just for a quick test I see no reason not to use the old head gasket if it isn;t damaged. Did that on my GSX750EX. Don't use gasket material on it's own.

    Stale laquered fuel in the carbs is one thing to watch for on a bike that's been out of commision for a while.

    Reg/Rect units are notorious for going on this era Suzuki and as well alternator windings in some cases.

    What you describe happening to the previous owner could well be just the battery getting so flat it couldn't provide enough spark. This happened twice to me on my cb550 until I replace the rectifirer then later reg and rect with an after market solid state set up.
    Turns out the head is cracked...

    Just got a quote for $1000 to weld up the head and reinsert the valve seats. Steep.

    Any ideas for remedying this cracking other than a full weld and machining?
    Any repair shops who would specialise in this?


    Sent from my iPhone using Tapatalk

  14. #14
    Join Date
    25th March 2004 - 17:22
    Bike
    RZ496/Street 765RS/GasGas/ etc etc
    Location
    Wellington. . ok the hutt
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    20,500
    Blog Entries
    2
    Wrecker for engine or parts. At some point very quickly you could over capitalise a GSX400. Keep that in mind. How much can I sell a good one for? How much will I actually spend? At some point even working for free it might be sell it on as spares and save for something else. It's what the last guy did, just more dishonest in description by the sounds.
    Don't you look at my accountant.
    He's the only one I've got.

  15. #15
    Join Date
    24th September 2004 - 06:46
    Bike
    '76 CB550 Super Sport
    Location
    On the road to nowhere...
    Posts
    7,414
    As above. Wrecker. That's what I did when I reconditioned the CB550s donk. The rocker box was worn and the engineer I took it said I wasn't worth welding it up.

    A grand is way over the top though.

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