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1978 GS750 issue
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Jesse002100
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Jesse002100
Here we go again now i have all the info after a few questions and alot of the search button. I got this 78 GS750 for a project which it has been so far. The last issue now is at a stop light, or a stop for 30 seconds or so or if you lean the bike to either side one or two of the carbs pours out gas for about a second. if you just let it sit after a min of so it will do the same. This bike starts up fast and easy, runs fine. Its just running *extremely* Rich.
I Rebuilt the petcock (before only worked on prime now seems fine) if anyone thinks that this still can be the isssue let me know.
Rebuilt the carbs from soaking in carb dip to new gaskets and o-rings there spotless (i am running a 4 into 1 header and K&N type pod filters)
I am going to try and set the carbs to the specs from the carb oem spec:
1978 GS750E Specs in mm.
Carb Type- Mikuni VM26SS
Bore Size- 26
ID# - 45030
Idle r/min - 1050 +/- 50
Fuel Level - 2.5-3.5
Float Height - 25-27 mm (How exactly do i set this??)
Main Jet - #100
Main Air Jet - 0.7 (Is this on the bottom of the float bowl or is this the top adjustment)
Jet Needle - 5F21-3
Needle Jet - O-6
Pilot Jet - #15
Bypass -
Pilot Outlet -
Valve Seat -
Starter Jet -
Pilot Screw -
Pilot air jet - 1.6 (Is this on the bottom of the float bowl or is this the top adjustment)
Throttle Cable Play - 0.5-1.0
I may only be 19 but im trying
If anyone has any other ideas to why this could be happening please let me know what to buy what to try whetever.
Thanks, Jesse
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Forum LongTimerGSResource Superstar
Past Site Supporter
Super Site Supporter- Mar 2006
- 35619
- Torrance, CA
Problem is your fuel height in the carbs is too high. You need to set the float height, you also may have a leaking float needle. The procedure to set float height is in the manual or do a search for info here. Making a fuel height gauge like shown in the manual also wouldn't be a bad idea. Check my signature...to measure is to know.
Ed
To measure is to know.
Mikuni O-ring Kits For Sale...https://www.thegsresources.com/_foru...ts#post1703182
Top Newbie Mistakes thread...http://www.thegsresources.com/_forum...d.php?t=171846
Carb rebuild tutorial...https://gsarchive.bwringer.com/mtsac...d_Tutorial.pdf
KZ750E Rebuild Thread...http://www.thegsresources.com/_forum...0-Resurrection
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Forum LongTimerGSResource Superstar
Past Site Supporter
Super Site Supporter- Mar 2006
- 35619
- Torrance, CA
Just saw your questions...
Set the fuel screw to .8 turns from lightly seated. Air screw should be 1.75. You very lightly turn the screw in until it bottoms and then count the turns as you open them. Hear is some info that may help... http://www.thegsresources.com/files/vm_carb_rebuild.pdf
Lastly, that spec in the service manual is wrong, set your float height to 24mm per the tutorial.
Good luck and keep going...Ed
To measure is to know.
Mikuni O-ring Kits For Sale...https://www.thegsresources.com/_foru...ts#post1703182
Top Newbie Mistakes thread...http://www.thegsresources.com/_forum...d.php?t=171846
Carb rebuild tutorial...https://gsarchive.bwringer.com/mtsac...d_Tutorial.pdf
KZ750E Rebuild Thread...http://www.thegsresources.com/_forum...0-Resurrection
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Jesse002100
well i have only one issue to the float test i have 2 drain plugs that are stripped bad from the previous owner, 2 i got off some how but i tried on the other 2 you have any ideas on how to get these out other then drilling?
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Jesse002100
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