Super Jet Yamaha 61X Motor Vibration

[edomund]

I bought a 61X motor off ebay to replace my 650 6M6 motor in my 90 SN. The motor was listed as remanufactured. It has new pistons (.5 over), rings, resurfaced head. They reused the crank saying it was inspected and found in spec.
http://cgi.ebay.com/ebaymotors/ws/e...0714675850&viewitem=&sspagename=STRK:MEWNX:IT

When I fired it up (connected to a hose bib) to check everything out, the motor vibrated a lot. I disconnected the midshaft just to isolate the vibration to the motor and to eliminate the possbiliblty of the midshaft alignment playing a part in the motor vibration. I fired it up again with no midshaft (drive line, pump etc.) connected and got the same vibration. I have 4 brand new motor mounts and shims. I was very worried about the vibration and noise coming from the motor, so I did not procede with the break-in process. I only ran the motor for maybe a total of 5 minutes.

I removed the cylinder from the crank case to investigate and found a few things. First the (front piston) sleeve has a chunk out of the skirt. Then I found the connecting rod has a bunch of marks on it like the chunk had been bouncing around in the motor. Also there are marks in the bottom of the crank case from the same thing. I'm assuming that the motor was rebuilt because of this failure. The seller has not got back to me yet.

I'm guessing the piece of skirt damaged the crank itself or crank bearings and this is the vibration I'm feeling. Am I correct?
Can the sleeve be used still?
Can I have the crank rebuilt?
Any suggestions for what steps to take in getting this motor back to working order?

Thanks in advance,
Ed

 

[tew08]

I would try to get money back. It looks like he is a solid seller, he may work with you.

Condition: Remanufactured: A properly rebuilt automotive part. The item has been completely disassembled, cleaned, and examined for wear and breakage. Worn out, missing or non-functioning components have been replaced with new or rebuilt components. It is the functional equivalent of a new part and is virtually indistinguishable from a new part. See the seller’s listing for full details.

 

[cattledog]

lots of ebay horror stories lately , i have not purchased anything for years on there i would lodge a complain

 

[edomund]

I'll try to get it resolved but if I keep the motor what am I looking at to get it running?
Have the crank rebuilt and run the top end? Pistons and rings are new and cylinder is honed.
Is the cylinder OK to run like this.
Any increased chance of it failing because of the chip? Its low enough it shouldn't affect the piston travel, right?

Thanks
Ed

 

[5810]

get a SBT CRANK or jet maniac crank, grind the chip smooth on sleeve, if there is no crack in sleeve... i would run it... Braapp