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Author Topic: Need piston ring help--78 CB750K  (Read 913 times)

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Offline Reindeer

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Need piston ring help--78 CB750K
« on: August 13, 2009, 02:57:13 PM »
After waiting nearly 2 months for the piston rings to arrive (I bought the bike with the engine disassembled and in boxes) I find that the rings are too wide to fit into the piston grooves. Neither of the top two fit. The label on the box for the rings says they're the correct ones, but I'm not sure.

Maybe I have the wrong pistons, or a non-original engine. The pistons are stamped with Honda on one side and 392 on the other. Serial # for the motor is CB750E-3004350 (serial # on the frame is CB750K-2804309).

Hoping someone can give me some guidance as I'm new to this and a bit frustrated--I want to get this thing on the road!
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75 CB750 hardtail bobber
78 CB750 project...might run someday

Offline moham

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Re: Need piston ring help--78 CB750K
« Reply #1 on: August 13, 2009, 03:38:25 PM »
With tight clearances, everything needs to be fit together just so. My recent experience
is with Kawasaki pistons/rings. The three piece oil rings needed to be fit in delicately or else would bind.
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Offline Jerry Rxman Griffin aka MuthaF'er

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Re: Need piston ring help--78 CB750K
« Reply #2 on: August 13, 2009, 04:00:29 PM »
You failed to list any info on the rings?? Honda?? Part number??
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As of today 3/13/2012 my original owner 75 CB750F has made it through 3 wives, er EX-wives. Free at last.  ;-)

Offline Reindeer

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Re: Need piston ring help--78 CB750K
« Reply #3 on: August 13, 2009, 05:53:22 PM »
The box is marked RIK and Riken. Has several different part #'s, main one is 13011-300-024 and 11-5005.
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75 CB750 hardtail bobber
78 CB750 project...might run someday

Offline bryanj

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Re: Need piston ring help--78 CB750K
« Reply #4 on: August 14, 2009, 02:56:12 AM »
Thats your problem 300 middle number is for the earlier 750 not the F series or later K
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Offline Jerry Rxman Griffin aka MuthaF'er

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Re: Need piston ring help--78 CB750K
« Reply #5 on: August 14, 2009, 09:52:11 AM »
+1  You need a -392 ring and not the -300

I'm sure someone here would love to have your -300 rings
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As of today 3/13/2012 my original owner 75 CB750F has made it through 3 wives, er EX-wives. Free at last.  ;-)

Offline Reindeer

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Re: Need piston ring help--78 CB750K
« Reply #6 on: August 14, 2009, 02:54:53 PM »
Thanks for the help. I ended up ordering the -392 rings from the local Honda dealer. More money, but at least they'll be correct.

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75 CB750 hardtail bobber
78 CB750 project...might run someday
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