Author Topic: 650 sohc vs 900 dohc  (Read 1580 times)

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Offline oddballmotorsports

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650 sohc vs 900 dohc
« on: April 01, 2017, 07:14:04 AM »
got a chance to grab a cheap 900.  does anyone know if the 900 dohc mounting holes are the same as a 650? or close? 

Offline CBJoe

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Re: 650 sohc vs 900 dohc
« Reply #1 on: April 01, 2017, 07:17:14 AM »
Are you talking about placing a 900 engine into a 650 frame?  I seriously doubt that there is any chance they are compatible
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Offline oddballmotorsports

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Re: 650 sohc vs 900 dohc
« Reply #2 on: April 01, 2017, 07:22:21 AM »
sorta..  the lower half of my frame is cb650, upper is a 200x 3 wheeler,  with a ton of custom bent tubing to connect the two lol..  just about ready to stab the 650 back in and stumbled on a 900 parts bike...  it would be nice if the bolt holes lined up, but I'm not that lucky...

Offline CBJoe

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Re: 650 sohc vs 900 dohc
« Reply #3 on: April 01, 2017, 07:27:15 AM »
Not sure...I suppose there's a possibility spacing is similar if you are just talking about the lower cradle, but I doubt it.  Can you physically compare measurements before buying?

Otherwise maybe as Honda_Dog for quick spacing measurements as he is cleaning up a 900F right now.  http://forums.sohc4.net/index.php/topic,162405.0.html

Joe
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Offline oddballmotorsports

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Re: 650 sohc vs 900 dohc
« Reply #4 on: April 01, 2017, 07:38:26 AM »
yup sure can...  hell I've thought about just bringing the motor or frame i built to compare..  just thought someone might know off the top of their head to save me from having to lug my crap around lol...

Offline 77F

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Re: 650 sohc vs 900 dohc
« Reply #5 on: April 01, 2017, 07:45:02 PM »
Don't have a clue on the cases never had a cb650 to compare. Own a 200x and Pop's got a CB900F that I helped do a lot of work two.  Got 84 rwhp out of stone stock engine. Stock degreed cams, RS 34's and dyna 2000 ignition started at 61 stock. Prob way more than you will ever see out of a 650 ! Difference in weight between the two engines might make a Difference though !
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Offline Don R

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Re: 650 sohc vs 900 dohc
« Reply #6 on: April 02, 2017, 11:36:41 AM »
The 650 originated from the 500 engine family, the dohc 750/900 bolt holes are closer to the 750 sohc engine family. I'd guess no.
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