Author Topic: 1972 500/4 Gearshift Question  (Read 134 times)

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Offline Dr. Frankenstein

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1972 500/4 Gearshift Question
« on: November 12, 2024, 09:36:42 AM »
I'm working on my '72 CB500 Four, trying to figure out if it needs a complete teardown. I have the engine up on the bench, cleaning it up and generally just going over it to see what's what, and I notice the shifter only wants to hit 1st, Neutral, 2nd and 3rd, and doesn't seem to want to shift up to 4th or 5th. I just have it on the table and going thru the gears to see if a complete teardown is warranted - it might be a silly question, but I should be able to go through all of them manually, yes..? The engine only has 10K on the clock and looks beautiful inside (not that that's indicative of proper function).

The now-deceased PO parked it under a shed for who knows how long - long enough for the shed to deteriorate and come down around it - so I have no idea why he parked it. As per my other posts, I know the engine was stuck, probably due to the pistons, but since I got the top end off everything rolls very smoothly, I just can't get it to shift into the upper gears. The shift dogs are still on the barrel where they should be, and there was nothing suspicious or any bits of metal in the sump when I took off the oil pan...the clutch rod is still in one piece too. I'm just looking for opinions here.

Offline Nurse Julie

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Re: 1972 500/4 Gearshift Question
« Reply #1 on: November 12, 2024, 09:41:45 AM »
Try wiggling the shaft back and forward, you should be able to select all gears that way.
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Offline bryanj

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Re: 1972 500/4 Gearshift Question
« Reply #2 on: November 12, 2024, 09:55:30 AM »
Both gearbox shafts need to turn to get all the gears with engine on bench
Semi Geriatric ex-Honda mechanic and MOT tester (UK version of annual inspection). Garage full of "projects" mostly 500/4 from pre 73 (no road tax in UK).

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Offline Dr. Frankenstein

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Re: 1972 500/4 Gearshift Question
« Reply #3 on: November 12, 2024, 11:30:51 AM »
Yeah, I decided to open her up; it's funny how you just turn ONE bolt -and then another one - and another one - it's like eating pistachios! You can't do 'just one'... ;D  I need the refresher anyway, and I want to vapor blast the cases. Should be fun! 

Offline HondaMan

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Re: 1972 500/4 Gearshift Question
« Reply #4 on: November 12, 2024, 04:09:56 PM »
I need the refresher anyway, and I want to vapor blast the cases. Should be fun! 

If you don't do those cases yourself, be SURE to tell the blaster guy to NOT blast on the mating surfaces.
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Offline Dr. Frankenstein

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Re: 1972 500/4 Gearshift Question
« Reply #5 on: November 12, 2024, 04:18:51 PM »
I was going to do it; I recently finally got a vapor blaster setup in the garage and freekin' Love It! Good reminder about the mating surfaces though; I was going to tape everything off anyway before I did it. That glass bead can get Everywhere!