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No vin on my engine

markm

CB750 Enthusiast
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michigan
Got a good deal on a engine. So I want to look up the year of the motor, It is a SOHC. Cant find any vin stamped on the motor where I find them on the other cb750 motors we have in the shop. I know where to look as we have 3 other 750s there to look at.
Could it be that it may be a case that was bought to rebuild or repair a motor and did not come on a bike but just a empty case?
trying to figure it out. any thoughts or suggestions on this would be appreciated. thanks.
 
You know of a way to identify an engine like this for buying parts and such for it? I read somewhere that some of the covers had more or less screws holding them on was a sign of changes but cant find that information again.
 
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Id probably check here http://www.sohc4.net/cb750k-serial-numbers/ You can look at your frame number and what they correspond with in terms of engine numbers (assuming it's a K model). This is of course assuming that the engine hasn't been swapped.

You could also use this: Screen Shot 2017-01-23 at 3.33.48 PM.png http://www.thisoldtractor.com/mg_manuals/book_motorcycle_identification.pdf
 
I appreciate the willingness to help, but no frame, was engine only purchase. my son bought the engine from a friend whos dad had it and passed away, was told it was a 73 engine and may have had work done on it and possibly a big bore kit. Not sure of any of this though.
 
It probably is a repacement case, but have seen a couple of race motors that had been put together with blank cases....they just went to the dealer and bought new cases instead of starting with a complete motor. Dealers that replaced the cases were supposed to stamp the old motor number onto the new case set but a lot didnt do it. only the early sand cast motors has different cover bolt numbers. cases are the same through the K6 motor after that the output shaft is offset farther out same as the F2 motor. If you tear it apart I can help you identify bore size and any other internal parts. If you are going to just run it then it will be really hard to determine if anything has been done internal. Any port work on the cylinder heads?? Look on the pad on the front of the cylinder on the front of cyl 1...stock they are stamped 736cc, some engine builders used to grind it off and stamp the new bore size. Also look for a casting number on the top fin on the back of the cylinder head. Post a couple of pictures and maybe I can help identify.
 
thanks for the info dd. I will be checking out places you suggested. Thanks a lot for all the assistance guys.
 
Went out to take a look I couldnt find the pads with stampings, Now I re read your post about the stampings that should be on the jugs right? I did see the supports between the fins and it has 3 oblong ones not the 4 or 5 round ones on the heads. So I think it must be later than 73 heads. I will have to tear the bags and tape off the motor to get a better look at it. My son sealed it all up to keep out the mud wasps.
 
The engine size stamping would be on the cylinder on #1 at the bottom on the front of the engine. The casting number would be on the top fin on the head if it has one. Take some pictures and I can try and help
 
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