Reply To: GV125C Tuning frustration

[Darkvader]

♠️ MARCEL wrote:

Congrats on your test! Stay in the hyo family lol. Keep the 125 for winter or short runs as i own one myself for just that or as a work horse sometimes (if car isn’t being used haha) , but keep an eye for a GT650 or GV650 🙂

Yep, i’m keeping the GV125 :), i’ve been keeping an eye on that Japanese GV250DRA something about that tickles me. obviously if a 650 or st7 comes along i’ll seriously consider that too.

On your GV125C – Few pointers if it helps;

• Float height 7mm sitting down (means float is gently resting on the needle) , 17mm lifted up… But 8mm is a generally a max limit when the carb is sitting on its diaphragm covers.

this has confused me slightly, though I think it’s more about the terms used. Would you be able to walk me through how you measure things?
I have a little video here https://youtu.be/lwInsUauWfc
in this video i have the float set at 7mm with a soft set on the diaphram covers. before this I tried a hard set, with the float at 7mm and the spring fully compressed so maybe like 10mm with the spring.
I assume as well the 17mm is the maximum open drop on the float, i measured 14mm earlier but i may have this completely wrong.

Tank Tap = Check OFF means OFF (Disconnect the hose safely and ensure the tap still doesn’t leak out fuel when its in OFF mode)

Change Floats = If in doubt about them

Change “Needle Seat” and “Float Needles” , these 2 are literally the only items that will stop the fuel coming in after the floats have risen (extra fuel will just overflow to cylinder overnight sometimes) – Hence “float jamming” being a common thing on carb motorcycles , it just means we have to extra be serious with them (unlike injectors lol)

140 psi via a flexi hose should be OK to make it “start” at minimum, the hard metal pipe is pushed down as we crank the engine or it shoots at you!😉 (Just make sure the metal bit uses a Spear Shape rubber tip.

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I tried the metal pipe one first, I made sure to get a tester with it, sadly I got worse numbers as i just couldn’t get a good seal even going full hulk. I think i must just have noodle arms though.
I actually reckon that the last time i adjusted the floats I may have set them too aggressively as I had a feeling the needle would bind up. it didn’t seem quite right

Sorry for all the potentially stupid questions, i’m just doubly making sure.
Thanks Marcel.