h00ty

[h00ty]

♠️ M77 wrote:

 
<p style=”text-align: center;”>12. Swap Main Jets</p>
<p style=”text-align: center;”>Install upgraded jets: one size up front & rear, depending on model. </p>

Stock Carb Jet Info:

• GT125 / GT125R & RC = 87.5 Front, 90 Rear
• GT250 / GT250R = 92.5 Front, 95 Rear
• GV125 Aquila = 87.5 Front & Rear
• GV250 Aquila = 90 Front, 87.5 Rear

Pilot jets remain stock: 125cc = 15, 250cc = 20

13. Install Upgraded Jets

<p style=”text-align: center;”>GT125/125R = 90 Front, 92.5 Rear GT250/250R = 95 Front, 97.5 Rear Aquila 125/250 = One size up</p>
<p style=”text-align: center;”>

</p>
 

Hi,

I try to change my main jets.

I have a Hyosung gv 125m e3 carby from 2007. On the main jets there is a 82,5 printed.

Is it safe to swap for 90 main jets? Or should I go for 85?

Greetings

Hooty

[h00ty]

♠️ M77 wrote:

h00ty wrote:

What rubber pipes and o rings do you mean?

Pipes = Sorry i meant the intake manifolds (which hold the carbs down to the cylinder heads) , so they also have o-rings in them, so if one of them got deformed during re-install or are too old , you could have a micro leak that has made the vacuum system weaker. Also make sure both front and rear intake pipe share vacuum to open the fuel pump. (2 intake pipes feeding the vacuum pump in a shared T-Junction (T-Piece) = better chance of fuel flow) If you see any egr parts (ais parts) get rid of it, your vacuum system will thank you, look here:

[How to Tutorial] AIS Removal Guide – Hyosung GV125 GV125C (EGR Blank Kit Fitting Guide)

https://hyoriders.club/forums/topic/ais-removal-guide-gv125c/embed/#?secret=svpFDuTGKQ#?secret=x0VbBrsQdq

Quote

ah… Thx for enlightening me 😊

I guess when I install the bigger main jets I could just swap them.

But I think I don’t have an ais system.

I read the post you mentioned but to follow this guide I would need more photos. I don’t know what he is up to in this guide, something like turning off the ais…

But I’m no mechanic and I don’t know all the parts that are mentioned.

But replacing the manifolds, that’s something I am capable of

Thanks again

😊

[h00ty]

I already put in a carby cleaner two consecutive times. And my only problem now it’s the loss of power when I ride at maximum speed for a period of time. The period is longer if the tank is full and shorter the less fuel I have left. It feels like the carburator runs dry.

So my guess is the membrane in the pump is too old to make the full stroke. It’s easier for the pump when the pressure is high from a full tank. That’s why I look at changing the fuel pump.

I tried to look for a new membrane but it’s costs as much as a new pump because I would have to import it.  o.o

Keep you updated when I changed the parts.

Packet should arrive on Tuesday.

=)

Thx for all the suggestions.

Maybe I try another cleaner after changing the pump

[h00ty]

I already inspected the carburetor once beforei got suspicious of the electric parts. The carburator looked clean. But I didn’t inspect the needles. That was before I found this forum.

I want to make sure that the fuel pump works correctly before I have to disassemble the carburator again. The last time it was pretty hard to fit it in again.

And yeah, since I found out about this forum I read a lot of posts here and yes I want to switch the main jets in the carburator but like I said, I wanted to make sure the pump works properly.

I make my analytics with ai and reading in this forum to get rid of all the failures that occurred. Works pretty good so far. When the new parts arrive I will make more photos of what I’ve done.

What rubber pipes and o rings do you mean?

And yeah I love this machine 😊

[Author]

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