Engine Size

[uthe54]

This might be a stupid question, but please bear with me because I'm still relatively new to these buggies.

I understand that there are countless different versions of these GY6 motors, and that each of them has their own differences. I recently got a used Razor Vision Z-2150R. The engine on it looks just like this one which is advertised as a 150cc engine.



It burns oil bad, so I was going to rebuild the top end of it and get a kit, but to make sure I was getting the right thing, I went ahead and took apart the top according to a guide I found somewhere online (can't remember where) and I noticed the cylinder stated 124cc.



Also, on this piece, it says 125.



Could any of you help me identify my engine? Is it a 150cc or a 125cc?

Thanks everyone.

[GX150]

It looks like a 125cc. The good news is that a 150cc or 155cc cylinder will fit without any engine case modification.

[olderthan]

it is a 125cc for sure can rebuilt as a 150 or 155 i sound like a echo of gx150 but he is correct

[uthe54]

Sweet! Thanks for the info guys. So I assume if I buy a 155cc big bore kit it will have everything I need to do this myself?

Would I need to order another one of these? (Not sure what it's called, sorry... the thing the arrow is pointing to)

[olderthan]

that is connecting rod if all your doing is burning oil you will not have to replace it call
tom @ syc and he will be able to fix you up

[ckau]

you really need to know what you have before ordering parts. check the number plate. it's on the right side of the case,as your facing the valve cover, stamped on a flat area below the cvt cover, beside the oil drain plug. anyone you talk to will want this numberin order to be sure your both on the same page.
For example: 157qmj { engine code for a 150}

(Digit #1) Corrosponds to the number of cylinders. All GY6 engines are single cylinder, so this number will always be 1.

(Digit #2 and #3) This is the bore size in metric millimeters, in the case of the 157QMJ,the bore is 57mm.

(Digit #4) relates to the style of engine. All GY6 engines are designated "Q".

(Digit #5 and #6) The actual size of the engine. The second letter ascends consecutively for each 10cc. MB = 50cc, MC = 60cc, MD for a 70, MH = 110cc, MI = 125cc, MJ = 150cc

[uthe54]

it's a 157FM. What does that mean?

I've been communicating with Tom. He's told me a couple additional things for me to check.

[Victorgoober]

Hi, i recently picked up a buggy with this same engine and also going to do a top end rebuild with a kit. I was wondering if you could possibly answer a question about rebuilding it as a 150cc. Was it able to be rebuild as 150cc with not many problems? and did you have to replace the connection rod?

[metalstudman1]

Can't say if Uthe54 had any issues, but yes you can rebuild as a 150cc.No you don't have to replace the connecting rod unless it's bent or the motor has been knocking and made the main bearing cap egg shaped.

[uthe54]

sorry for the late reply. I ended up buying a new engine. they were cheap enough and I didn't want to spend all the money rebuilding and not have it work in the end, so I took the lazy way out. Turns out to have been a not-so-bad idea as now I have a second parts engine down in my basement.

[Victorgoober]

Ok, Thanks.

[paul]

That works.