Dear Sir I have a VMOTO 125cc Monaco engine QJ153, I would like to know, what upgrade 150cc piston and head kit would fit my bike and what would be the total cost? an answer would be most appreciated. I have already purchased parts from You. – Upgrader in Houston


Nice to see you again, and thanks for your tech question. Your engine designator QJ153 is decoded as such. The QJ stands for the manufacturer, which is Quanjiang, a quality factory in Zhejiang province of China. The first number is the number of cylinders, 1. The last two, 53, is the diameter of the bore, 53mm. Often there is a suffix of three letter, in your case, a QMI or a QMJ, this denotes the engine style. The Q would suggest a GY6 type configuration.

I would suggest our 150cc standard bore kit for just 59.95 delivered priority mail. You can upgrade the head to a 150, however it is not necessary. Heads are 49.95 additional. I have found that often the smaller combustion chamber of the 125 makes for a nice high compression engine. The 150 is a 57mm standard. We also have 59mm, which is the largest upgrade without machining of the cases.

Thanks for your interest. You can order by phone, email, or by secure server via Paypal payments on this link.