Advice for a tunned gy6 152qmi efi engine

sgtavs · 12-28-2020, 02:38 PM

Good afternoon,

I have a chinese scooter using a 152qmi engine with injection (euro4 model).

The generic brand/model of the scooter is "Jiajue JJ125T-23" but the spanish imported brand is called "SUMCO". Here a pic of this exact model.

The scooter runs great and it already has 8650km on it. 5000km ago I bought a complete transmission kit from NYC and also a 14 x 36 gear kit.

Last week I've installed new upgrades. A9 camshaft, titanium valve springs, 150cc cylinder with the same head so now I have more compression and a performance exhaust.

The problem now is, when I run slow it runs great but if I fully open the gas the engine practically stalls, so I supose it needs more gas in the mix(it also may need more air as I still use the stock filter and filter box).

Today I went to a specialized shop to see if they can reprogram the Delphi MT05 ECU but before going all in with this (I think it's a must to do this) I need to find a bigger injector and fuel pump for this engine.

Can someone tell me which "performance" fuel pumps could go well for this? And also where I can start to search for bigger injector replacements. I'm a carburettor guy and this injection thing is new for me.

Thank you very much

12-28-2020, 02:38 PM	#1
sgtavs Join Date: Sep 2020 Location: Spain Posts: 3	Advice for a tunned gy6 152qmi efi engine Good afternoon, I have a chinese scooter using a 152qmi engine with injection (euro4 model). The generic brand/model of the scooter is "Jiajue JJ125T-23" but the spanish imported brand is called "SUMCO". Here a pic of this exact model. The scooter runs great and it already has 8650km on it. 5000km ago I bought a complete transmission kit from NYC and also a 14 x 36 gear kit. Last week I've installed new upgrades. A9 camshaft, titanium valve springs, 150cc cylinder with the same head so now I have more compression and a performance exhaust. The problem now is, when I run slow it runs great but if I fully open the gas the engine practically stalls, so I supose it needs more gas in the mix(it also may need more air as I still use the stock filter and filter box). Today I went to a specialized shop to see if they can reprogram the Delphi MT05 ECU but before going all in with this (I think it's a must to do this) I need to find a bigger injector and fuel pump for this engine. Can someone tell me which "performance" fuel pumps could go well for this? And also where I can start to search for bigger injector replacements. I'm a carburettor guy and this injection thing is new for me. Thank you very much
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