So I recently got a 61x motor off ebay and started to swap my 650. When I initially inspected the motor, I noticed it was stamped 61x on the top case and assumed all was good. Today as I was installing gaskets, I noticed the cylinder and bottom case are both stamped 6m6... What the hell did I buy? See photos below for reference, is this some frankenstein motor and I got burnt on it?
Help! What motor do I have?
- Thread starter Th3 VVay
- Start date
- Location
- North Carolina
I could be very wrong but I'm pretty sure all bottoms are stamped 6m6. It looks like (to me) you have a 61x bottom end with a 650 cylinder, And 61x head.
yamabro
GP Performance / Patterson Powersports
- Location
- Dickson, Tn.
You can tell by the perfectly square exhaust thats a 650 cylinder.
And you are correct,... You got burned, 650 cylinder on a 61X bottom.
And you are correct,... You got burned, 650 cylinder on a 61X bottom.
- Location
- North Carolina
Yep
Well poop... luckily I have the guys number because I talked to him prior to buying it. He seemed to have a bunch of different motors so maybe he didn't realize. Hopefully it was an honest mistake on his part and he's cool about refunding me or there's gonna be hell to pay. In regards to the bottom case, are they all stamped 6m6?
yamabro
GP Performance / Patterson Powersports
- Location
- Dickson, Tn.
Hopefully they are not a member on the "X"
Yami-Rider
TigerCraft FV-PRO
- Location
- Texoma
Yes, the very bottom case is 6m6 on 650, 701 and 760
- Location
- Denver, NC
Correct
- Location
- Canberra, Australia.
If you haven't already installed the head gasket can you measure the bore diameter and post the result?Also, an image of the intake side, along with the engine serial number/engine family I.D. plate would help.
Probably not going to make things better for you but at least we'll be able to tell you EXACTLY what you have.
Probably not going to make things better for you but at least we'll be able to tell you EXACTLY what you have.
Where is the engine ID plate located? And I didn't pull the head because I was supposed to just swap my parts from the 650 and drop this in. Compression is supposedly 150 each cylinder. Starting to second guess that would be the case...
Yami-Rider
TigerCraft FV-PRO
- Location
- Texoma
Doesn't really matter what the bore is, they are 650 cylinders, with 650 porting. Even if they have been bored up, still have the poor port work of a 650 cylinder. I would try to get a refund or 61x motor.
Exactly what I was thinking. I'll be pushing for a refund and disputing with pay pal if he is not accommodating. Worst case I'll be in the market for a 61x cylinder and just rebuild the top end so it's all fresh.
- Location
- North Carolina
They work. But I would say the domes are a tic larger.
- Location
- Canberra, Australia.
I would define a 61X motor as the stock engine as found in a '94 or '95 Waveblaster, '95 Superjet (amongst others). It should consist of 61X bottom end running a single carb mounted to a manifold (which should have the engine serial number/family ID affixed to it) bolted horizontally to the crankcase. Cylinder will be running at LEAST an 81mm bore. Cylinder head should have an "X" cast in its surface and the diameter of the domes should measure a little over 81mm.
I don't know exactly how the engine was described by the seller but I would expect you would need as much evidence as possible If entering a dispute with them. At the moment we have an assessment based solely on the cylinder exhaust ports. Although that may be definitive as regards the cylinder it still leaves a question mark over the rest of the motor.
I would ask that you post the seller's description of the motor and provide more images of identification castings on the head as well as the inlet manifold area (including ID plate). When that is available we'll be able to provide an assessment of how far the seller's description varies from what you have.
P.S. Don't expect you to pop the cylinder head to determine the bore diameter. You mentioned you were changing gaskets and thought there was a chance that included the head gasket, also.
I don't know exactly how the engine was described by the seller but I would expect you would need as much evidence as possible If entering a dispute with them. At the moment we have an assessment based solely on the cylinder exhaust ports. Although that may be definitive as regards the cylinder it still leaves a question mark over the rest of the motor.
I would ask that you post the seller's description of the motor and provide more images of identification castings on the head as well as the inlet manifold area (including ID plate). When that is available we'll be able to provide an assessment of how far the seller's description varies from what you have.
P.S. Don't expect you to pop the cylinder head to determine the bore diameter. You mentioned you were changing gaskets and thought there was a chance that included the head gasket, also.
I mean did we not all just figure it out.... it says 6m6 on the casting on the cylinder and the ports are square.... jury says.... dirkdiggler strikes again
Man that sucks they did that too you.
Get a refund or have that guy send you a 61x top end. Seems like they were out to burn someone... You don't just take the 61x cylinder(the most important part) and stick a 6m6 on there without knowing. The compression should be lower with that head on there. No telling if it got new 701 sleeves put in or something.
I had a 6m6 cylinder with 701 sleeves in it. It was ported so I don't know what it looked like to begin with.
Get a refund or have that guy send you a 61x top end. Seems like they were out to burn someone... You don't just take the 61x cylinder(the most important part) and stick a 6m6 on there without knowing. The compression should be lower with that head on there. No telling if it got new 701 sleeves put in or something.
I had a 6m6 cylinder with 701 sleeves in it. It was ported so I don't know what it looked like to begin with.