Gv125c Float question
- This topic has 7 replies, 3 voices, and was last updated 2 years ago by
.
-
Posts
-
-
Hi, In the last week i rebuilt my carb and amazingly put everything back where the bike started up first try!. it seems so much happier too where i am able to do 70 down the dual carriageway comfortably again! However I have a small issue.
I used the old floats but new seats so I checked where the floats were sitting and measured 10mm, so adjusted them down to 7mm but found that at 7mm it would compress the spring in the needle completely and had no spring, so i adjusted back up to 8mm, where it seemed happy. (and the seats where working, i did the blow test where i blew into the carb and could tell the pressure difference between them open and closed.)
However
I now have the opposite running problem, my front cylinder is running completely rich and i’m wondering if I measured the floats correctly before I start playing with the slides. Can I ask how it’s done properly? i think i may have made a goofball mistake. I did leak test the carb off the bike for 2 hours and found that it wasn’t flooding but i just want to make sure.
Thanks Guys.
-
-
The (above) “wet”-test is the best. The manual can be confusing, but the 7mm measurement is on “full/hard-stop”, – spring compressed. Most often (on other carbs) measurement is on “light-touch”.
Old and grumpy,(?), have fairly wide engine & tuning experience, "restoring/resto-mod" on cars & mc, worked as electronic tech. (retired).
GT125R - sold. New (used): 2012-GT250R-efi (sold)+ 2017-GV-125C (sold) - got my old 2018-GT-125R back... 🙂
-
With a “make-it-easier”-tool
Old and grumpy,(?), have fairly wide engine & tuning experience, "restoring/resto-mod" on cars & mc, worked as electronic tech. (retired).
GT125R - sold. New (used): 2012-GT250R-efi (sold)+ 2017-GV-125C (sold) - got my old 2018-GT-125R back... 🙂
-
The (above) “wet”-test is the best. The manual can be confusing, but the 7mm measurement is on “full/hard-stop”, – spring compressed. Most often (on other carbs) measurement is on “light-touch”.
oh, that’s news to me! that would be why the measurement threw me. thank you 🙂 Guess i’ll have to pull the bowls off and get that float set correctly again, will also give me an opportunity to rejet too, i’m still rocking the 82.5s.
that’s a handy little tool. -
Best way to measure, you can ofcourse use other tools.
But the manual-stated 7 mm, means floats on a “hard” stop. (Not the common way…).
Old and grumpy,(?), have fairly wide engine & tuning experience, "restoring/resto-mod" on cars & mc, worked as electronic tech. (retired).
GT125R - sold. New (used): 2012-GT250R-efi (sold)+ 2017-GV-125C (sold) - got my old 2018-GT-125R back... 🙂
-
Problem with Yamaha’s is that 90% of their own parts sometimes do not work on the Hyosungs because the requirements of a Hyosung , to differ for Yamaha . Hence even if we have their twin carbs, you will see even the exterior parts differ in some places , i’d stick with Korea’s manuals even tho they can be vague sometimes lol. A part from a yamaha that is 1mm off , tends to throw things off real bad , i found out the hard way (Marcel must not buy Yamaha carbs!) , hell we can’t even use their own float covers without issues later lol.
-
Thanks everyone!
I set the float height today, it’s a good job I decided to bite the bullet and do it again, not only did I originally measure it wrong but I also discovered the seat needles in the rebuild kit are ever so slightly shorter with a bigger spring.
I actually found a tool that i already had that did the same thing, a tyre tread depth guage. that measured 4mm that i had it set at after my first rebuild. it’s now running more sensibly. the cold starts are a bit hit and miss still but I think that’s pilot circuit related, it still seems to run lean at idle (revs gradually climbing +150 rpm over a minute, then coming down after a blip of throttle).
Yes, I had a look at my 650 today, the set up between the carbs is quite a bit different, there’s quite a lean on the carbs (towards the front) for a hyosung, which i imagine can change how the floats operate a bit, i wouldn’t mix and match too much but useful to know there’s some knowledge that is transferable :).To be honest, I’ve been eyeing up making up an electric pump conversion, i’m still having issues with the pump on mine and that’s after 3 cleans AND completely new vacumm lines. I’m thinking a 1psi electric fuel pump (looking at the setup my my xvs650, one of those pumps \could potentially\ work, the pressure switch for the pump is built into the pump itself), small relay, tilt switch, fuse and fuse holder and three wires. I’ll have to experiment, that vaccum pump is making me go mad :P.
-
- You must be logged in to reply to this topic.