Topic: cylinder pins on a 750 F2 engine

[mazingerzeca]

Hello all.
I'm rebuilding my cb750 F2 engine. When I disassembled the cylinder, I took some pictures in order to remember where the pins go. The fact is that I've seen on the parts list that there are 4 short lenght pins (12x14) and 4 long lenght pins (12x18), but they don't specify if the go on the upper/lower side or in which hole. Moreover, in my pictures I can see more than 4+4 pins, but I can not see which lenght are they. Does anyone how many pins do I have to install and in which holes, and which of them have the rubber around them? Thank you.

[750essess]

Install all the pins in the cylinder block for reassembly to hold the gasket in place ( one usually sticks in the head though, you can leave that alone if it is) The longer ones, IIRC go in the middle with the rubber sleeves around them. Would positions
2,3,4,5,8,9,10,11 in the pic of the cylinders. The 2 o-rings go in the shallow recesses next to the chain tunnel

[upperlake04]

  I don't have the cycle experience of 750essess so I hesitate to contradict his suggestions, but my notes from the F3 rebuild are slightly different.    From notes marked in the Clymer manual..

- 4 dowels in front corners, top and bottom, same lengths 1,6,13,16
- 4 dowels, same lengths, with rubber sleeves,  2,8,5,11
- o-rings around the 2 oil jet orfices
- o-rings around bolts,  bottom of cylinder, red arrows

  4500 miles, no leaks   

[750essess]

Oh Shoot, wasn't thinking about the ones in the bottom of the cylinder. The top goes like I said with just dowels at 1 and 6 too in first pick. The bottom has dowels at 13 , 16 in second pic and possibly o-rings at 18,19. To make sure fit the dowels in one side and measure the height, then insert in other side and see if it goes in at least that far. Also when you put the gasket on it will give you an idea where everything goes by the size of the holes. if you are using a cometic gasket it will not have holes big enough where the rubber sleeves go. Upperlake has it right right, but I pretty sure there are 8 dowels with rubber sleeves not 4...I think...my memory is gone 

[mazingerzeca]

  I don't have the cycle experience of 750essess so I hesitate to contradict his suggestions, but my notes from the F3 rebuild are slightly different.    From notes marked in the Clymer manual..

- 4 dowels in front corners, top and bottom, same lengths 1,6,13,16
- 4 dowels, same lengths, with rubber sleeves,  2,8,5,11
- o-rings around the 2 oil jet orfices
- o-rings around bolts,  bottom of cylinder, red arrows

  4500 miles, no leaks   

Looking at the shape of the holes, it looks right. I think the bigger ones go on 1,6,13,16, and also in the picture seems bigger. Thanks.

[mazingerzeca]

Oh Shoot, wasn't thinking about the ones in the bottom of the cylinder. The top goes like I said with just dowels at 1 and 6 too in first pick. The bottom has dowels at 13 , 16 in second pic and possibly o-rings at 18,19. To make sure fit the dowels in one side and measure the height, then insert in other side and see if it goes in at least that far. Also when you put the gasket on it will give you an idea where everything goes by the size of the holes. if you are using a cometic gasket it will not have holes big enough where the rubber sleeves go. Upperlake has it right right, but I pretty sure there are 8 dowels with rubber sleeves not 4...I think...my memory is gone 

Maybe you are right, because when I disassembled the engine, there were 8 dowels with rubbers. Anyway, it won't be bad to put 8 instead 4... Thanks.