Page 2 of 2 FirstFirst 12
Results 16 to 23 of 23

Thread: About a GP125 engine

  1. #16
    Join Date
    25th March 2004 - 17:22
    Bike
    RZ496/Street 765RS/GasGas/ etc etc
    Location
    Wellington. . ok the hutt
    Posts
    20,500
    Blog Entries
    2
    The clutch is under the seat, that's not it.

    OK so let me guess. You've removed the air filter haven't you? The carb will need bigger jets. Go 2 sizes up on main & see what it's like. Wind the mixture screw in most of the way in while you are there.

    ESE guys might have a better starting point than this. Running without filter will cause lean condition that will seize the engine unless compensated for with bigger jets. Any big change will (may) need some compensation one way or the other.
    Don't you look at my accountant.
    He's the only one I've got.

  2. #17
    Join Date
    5th June 2005 - 18:35
    Bike
    CBR 150.RGV250 Bucket
    Location
    UNZUD
    Posts
    355
    Blog Entries
    1
    You should be able to suss the clutch without the engine going, just pushing it.
    All I can think of is it's out of tune, ignition or carb set up, it's not in first ( yeah i know that seems obvious) or the clutch could have locked up....or a seized wheel bearing, which would be obvious too.
    Life is a lesson-if I bother to listen

  3. #18
    Join Date
    25th March 2004 - 17:22
    Bike
    RZ496/Street 765RS/GasGas/ etc etc
    Location
    Wellington. . ok the hutt
    Posts
    20,500
    Blog Entries
    2
    I think he is saying 'wants to die', not like stalls straight off as if clutch locked.
    Don't you look at my accountant.
    He's the only one I've got.

  4. #19
    Join Date
    4th November 2003 - 00:41
    Bike
    Yamama R6 & Frankie the Bucket
    Location
    Wellington
    Posts
    1,955
    Sounds like it's fucked...you should give it to me
    The Unknown Rider

  5. #20
    Join Date
    30th September 2008 - 09:31
    Bike
    Suzuki GP125 Bucket
    Location
    Auckland
    Posts
    1,969
    Quote Originally Posted by F5 Dave View Post
    I think he is saying 'wants to die', not like stalls straight off as if clutch locked.
    Clutch plates stuck together? How hard is it to push in gear with the clutch pulled in? Has the rotary valve been cut? massive air leak from the left hand oil seal? If its been a bucket before, does it still have the original carb? Are the jets and float height as per spec's? Is there any compression, whats the ignition timing, and is it CDI or points? Condenser shot?

    There were several different carb setups used by Suzuki on the GP's and although, all the std GP carbs we have seen all looked the same the jetting was different, the jets and setups are listed in the Suzuki manual.

    Some carb tuning info and theory here:- http://www.dansmc.com/carbs2.htm

    On the team ESE's GP's all the mains had to be changed and finished up anywhere from 95 to 110 depending on the bike, but the pilot jet, needle and needle jets were Ok as is, although some of the bikes benefited from enriching the slide.

    As there was a flat spot at the quarter throttle position, and that is about the place you use when your just trying to move off.

    We enriched the slide by reducing the height of the cutaway. This was done by turning 0.5 to 0.75mm from the bottom of the slides.

    Also the height the needle jet stands up in the carb throat has a very big effect on mixture strength or atomization around eighth to half throttle, shorter is weaker and a too short a one accidentally fitted from another carb caused no end of trouble with a major flat spot and was really un rideable. Pic-01
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	Needle Jet.jpg 
Views:	7 
Size:	201.1 KB 
ID:	204591  

  6. #21
    Join Date
    14th November 2009 - 11:52
    Bike
    1991 yamaha fzr250,
    Location
    upper hutt
    Posts
    14
    Thanks guys ill try this and hopefully it will work.

  7. #22
    Join Date
    18th May 2007 - 20:23
    Bike
    RG50 and 76 Suzuki GP125 Buckets
    Location
    Auckland
    Posts
    10,473
    .

    From:- http://www.iwt.com.au/mikunicarb.htm

    The slide valve affects carburetion between 1/8 thru 1/2 throttle. It especially affects it between 1/8 and 1/4 and has a lesser affect up to 1/2. The slides come in various sizes and the size is determined by how much is cutaway from the backside of it, fig 3. The larger the cutaway, the leaner the mixture (since more air is allowed through it) and the smaller the cutaway, the richer the mixture will be. Throttle valves have numbers on them that explains how much the cutaway is. If there is a 3 stamped into the slide, it has a 3.0mm cutaway, while a 1 will have a 1.0mm cutaway (which will be richer than a 3).
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	slide.gif 
Views:	4 
Size:	2.4 KB 
ID:	204690  

  8. #23
    Join Date
    5th June 2005 - 18:35
    Bike
    CBR 150.RGV250 Bucket
    Location
    UNZUD
    Posts
    355
    Blog Entries
    1
    Just to make your life even harder, I have had problems with the ignition windings under the flywheel, LH side of motor.
    The only way to test is to replace with another one of the same type.
    If you come up to Kaitoke tomorrow ask for Tex on bike 33, and I might be able to help.
    Check over your carb first, if it has'nt been fooled with too badly it should be able to be set up without too much grief.
    Life is a lesson-if I bother to listen

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •