Author Topic: Which is the right way to set the valves the Clymer Honda manual or the Service  (Read 823 times)

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Offline gbal06

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Which is the right way to set the valves the Clymer Honda manual or the Service Manual. Clymers says to rotate 1.4 to TD and set 1 an 4 I/E valves and then rotate 2.3 TDC and do the rest. The service manual says different (see) pics.  Which is the correct way?  Is there a pro/con to doing it either way?  Thanks

Offline ekpent

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 An easy way so as not to confuse is to go to tdc on #1. The lifter should wiggle. Set the lash. Roll engine over to 1/4 tdc again and set the lash on #4 if the lifter wiggles. Repeat above with 2 and 3.
  There are some other ways but this keeps it pretty simple.
« Last Edit: June 10, 2021, 11:32:20 AM by ekpent »

Offline PeWe

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An easy one is to start with 1:4. Rockers on cyl 1 should be loose, pads on base circle. If not rotate the crank 360* so 1:4 'T' match case mark again.
Adjust IN and EX, cyl 1

Rotate crank 180* to 2:3 and do cyl  2.
Rotate crank another 180* to 1:4 and do cyl 4.
Rotate to next 2:3 and do the 3.
Now double check, rotate to next which is 1:4  cyl 1..... Double check that nuts are tightened.

This with plugs out so you can use the big nut on ign side.
I used kicker last time, easy with plugs out that need a check st the same time anyway. They tell how the engine feels.

I do not do the tiny Honda lash on my stock CB750K2. 0.05/0.08mm.

0.1mm (0.004") feeler gauge both IN and EX.

In at 0.05mm can easy become 0.0 or worse with burned valves and seats.
I have no problem to skip 0.05 mm lift ;)
Maybe higher compression longer cooling time for valves ;D

Performance cams have usually 0.004"/0.005" valve lash.

Or with my metric tools 0.1/0.15mm. (0.004"/0.006")
« Last Edit: June 10, 2021, 10:57:48 PM by PeWe »
CB750 K6-76  970cc (Earlier 1005cc JMR Billet block on the shelf waiting for a comeback)
CB750 K2-75 Parts assembled to a stock K2

Updates of the CB750 K6 -1976
http://forums.sohc4.net/index.php/topic,180468.msg2092136.html#msg2092136
The billet block build thread
http://forums.sohc4.net/index.php/topic,49438.msg1863571.html#msg1863571
CB750 K2 -1975  build thread
http://forums.sohc4.net/index.php/topic,168243.msg1948381.html#msg1948381
K2 engine build thread. For a complete CB750 -75
http://forums.sohc4.net/index.php/topic,180088.msg2088008.html#msg2088008
Carb jetting, a long story Mikuni TMR32
http://forums.sohc4.net/index.php/topic,179479.msg2104967.html#msg2104967

Offline gbal06

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great thanks

Offline fxef79

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Your description of the Clymer method seems very wrong. So based on that, definitely Honda manual. That said, I think your description of the Clymer method must be mistaken. There’s no way they’d suggest set 1/4 TDC, do the #1 intake and exhaust, rotate crank and then do ALL THE OTHERS ?  Doesn’t make sense. I think you’re quoting Clymer’s wrong.


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Offline fxef79

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That said, personally I have one big gripe about the Honda manual method:  I always screw it up. It’s exactly right, don’t get me wrong. I just don’t understand what engineer said “hey, let’s make a visual chart that is the mirror image of what the visual layout is of the actual valves”. Think about it… you’ve got it at 1/4 TDC and you’re looking down at the top of your engine. Cylinder 1 is at the left, just like in the diagram. But they have intake as the top row and exhaust as the bottom row. Should be the other way. Then it would match the visual layout as you look at the engine. I keep trying to set intake and exhaust on #1, then I move on to intake of #2 and spend 30 minutes #$%*ing because it’s so tight, trying to figure out what has gone wrong with the valve train. Then after backing it all the way out I finally realize I’m reading the chart wrong and should have been doing #2 exhaust.

Probably just me.


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Offline PeWe

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Honda CB750 shop manual has the strange procedure to set the valves. I do not trust it.
Better as I described earlier (and others have written on this forum) to be really sure.

This is visible when valve cover is off and see which rocker arm pads that rests on the base circle, not lifted by the lobes.
CB750 K6-76  970cc (Earlier 1005cc JMR Billet block on the shelf waiting for a comeback)
CB750 K2-75 Parts assembled to a stock K2

Updates of the CB750 K6 -1976
http://forums.sohc4.net/index.php/topic,180468.msg2092136.html#msg2092136
The billet block build thread
http://forums.sohc4.net/index.php/topic,49438.msg1863571.html#msg1863571
CB750 K2 -1975  build thread
http://forums.sohc4.net/index.php/topic,168243.msg1948381.html#msg1948381
K2 engine build thread. For a complete CB750 -75
http://forums.sohc4.net/index.php/topic,180088.msg2088008.html#msg2088008
Carb jetting, a long story Mikuni TMR32
http://forums.sohc4.net/index.php/topic,179479.msg2104967.html#msg2104967

Offline StockRider

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That said, personally I have one big gripe about the Honda manual method:  I always screw it up. It’s exactly right, don’t get me wrong. I just don’t understand what engineer said “hey, let’s make a visual chart that is the mirror image of what the visual layout is of the actual valves”. Think about it… you’ve got it at 1/4 TDC and you’re looking down at the top of your engine. Cylinder 1 is at the left, just like in the diagram. But they have intake as the top row and exhaust as the bottom row. Should be the other way. Then it would match the visual layout as you look at the engine. I keep trying to set intake and exhaust on #1, then I move on to intake of #2 and spend 30 minutes #$%*ing because it’s so tight, trying to figure out what has gone wrong with the valve train. Then after backing it all the way out I finally realize I’m reading the chart wrong and should have been doing #2 exhaust.

Probably just me.


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+1, agreed. It would make more sense if it were like below...
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