Found the reason for over fuelling! – GT125R Carb Issues

[Brian]

So I found that the previous owner of this Hyosung gt15r had put in jets that where 122!!! I have replaced them now with rear 92.5 and 90 front. They have also messed with the mixture screws as the plugs still foul. Does anyone know where they roughly should be set? Thank you everyone in advance! 

[♠️ M77]

the last keeper is a moron! 122 ? wow not even a 300cc will run well with that jet size, that’s almost 650cc teritorry!

The factory mixtures is around 3 turns front and 3.5 turns rear , though  2.5F / 2/75R is OK.

[Brian]

Thanks for all your help, unfortunately, the bike has lost compression, in front cylinder. Seems it had been abused to much. Now looking for a new engine.

[♠️ M77]

Do you want to check ebay for used cylinders and pistons ? I have loads there worth a rebuild to try!

I will get a cylinder “head” (valves) soon , listed up there but im sure your valves are okay , if they need rebuilding , the first thing is usually the valve seats that drip out oil in to plugs

Don’t forget you need engine gaskets too (can’t re-use old ones)

[Brian]

Where di i get the gaskets from? Trying to locate them

[Brian]

And i bought one of your pistons i think from ebay

[♠️ M77]

We have gaskets in the shop,  see link below:   (if you need a gasket that isn’t mentioned on the shop, send us an email at the bottom of the website)
https://hyoriders.club/shop/

PS.   Thanks for your order, piston was sent today.

[Author]

Posts

[Brian]

So I found that the previous owner of this Hyosung gt15r had put in jets that where 122!!! I have replaced them now with rear 92.5 and 90 front. They have also messed with the mixture screws as the plugs still foul. Does anyone know where they roughly should be set? Thank you everyone in advance! 

[♠️ M77]

the last keeper is a moron! 122 ? wow not even a 300cc will run well with that jet size, that’s almost 650cc teritorry!

The factory mixtures is around 3 turns front and 3.5 turns rear , though  2.5F / 2/75R is OK.

[Brian]

Thanks for all your help, unfortunately, the bike has lost compression, in front cylinder. Seems it had been abused to much. Now looking for a new engine.

[♠️ M77]

Do you want to check ebay for used cylinders and pistons ? I have loads there worth a rebuild to try!

I will get a cylinder “head” (valves) soon , listed up there but im sure your valves are okay , if they need rebuilding , the first thing is usually the valve seats that drip out oil in to plugs

Don’t forget you need engine gaskets too (can’t re-use old ones)

[Brian]

Where di i get the gaskets from? Trying to locate them

[Brian]

And i bought one of your pistons i think from ebay

[♠️ M77]

We have gaskets in the shop,  see link below:   (if you need a gasket that isn’t mentioned on the shop, send us an email at the bottom of the website)
https://hyoriders.club/shop/

PS.   Thanks for your order, piston was sent today.

[Author]

Posts