Author Topic: QUESTION FOR cb 350 TWIN ACES  (Read 3599 times)

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Offline Killer Canary

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QUESTION FOR cb 350 TWIN ACES
« on: August 16, 2008, 02:36:56 PM »
hELLO, I'm in the process of  rebuilding my motor, which was running well but had various oil leaks. It seemed to me that the valves were noisier than the sohc fours even when properly adjusted. Now with the rocker cover off I see that the rockers each move side to side a good 15 thou which is probably producing the noise.
Is this normal or are there shims/washers that a PO might have forgotten to install
Thanks, I need to know before I can button my motor back up.
If it's worth doing at all it's worth over-doing.
Honda MT250, CB400F, CB450K, CB550, GL500, CBR929
Kawi GPz900, H1

Offline tbpmusic

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Re: QUESTION FOR cb 350 TWIN ACES
« Reply #1 on: August 17, 2008, 06:47:39 AM »
There is no spec listed for  tappet sideplay in the Honda Manaul, nor am I aware of one.
So it's probably irrelevant.

There are no washers that I'm aware of.
The 350 is a noisy head, even when the tappets are spot on.

bill2

"If you can't fix it with a hammer, then it's an electrical problem"

Bill Lane
 '71 CB450 Mutant/ '75 CB200/ '81 CM200/ '71 C70M

Offline Honda!

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Re: QUESTION FOR cb 350 TWIN ACES
« Reply #2 on: August 17, 2008, 08:28:40 AM »
There is no spec listed for  tappet sideplay in the Honda Manaul, nor am I aware of one.
So it's probably irrelevant.

There are no washers that I'm aware of.
The 350 is a noisy head, even when the tappets are spot on.

bill2



Agreed, my 350 always made tons of valve train noise, even when adjusted properly.
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Offline Killer Canary

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Re: QUESTION FOR cb 350 TWIN ACES
« Reply #3 on: August 17, 2008, 05:20:26 PM »
That's about as clear as it gets, thanks folks.
Love this motor, though.
If it's worth doing at all it's worth over-doing.
Honda MT250, CB400F, CB450K, CB550, GL500, CBR929
Kawi GPz900, H1

Offline Green550F

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Re: QUESTION FOR cb 350 TWIN ACES
« Reply #4 on: August 21, 2008, 07:45:57 PM »
Noisy is a relative term. I grew up in a IH tractor repair shop! ;D
Still I love the adjustment! easier than a 550 and kicks the crap out of shim-under-bucket that my suzuki had.
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Offline lordmoonpie

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Re: QUESTION FOR cb 350 TWIN ACES
« Reply #5 on: August 24, 2008, 01:07:53 PM »
Yep it's normal - the side float on the CB350 cam is quite alarming too. On my racer where the cam cover and points mechanism was all thrown away, you could rev the motor and watch the end of the camshaft move a good 2mm and this was in a 48bhp motor that revved to 12 thou!
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Offline Raul CB750K1

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Re: QUESTION FOR cb 350 TWIN ACES
« Reply #6 on: August 25, 2008, 12:49:02 AM »
Yep it's normal - the side float on the CB350 cam is quite alarming too. On my racer where the cam cover and points mechanism was all thrown away, you could rev the motor and watch the end of the camshaft move a good 2mm and this was in a 48bhp motor that revved to 12 thou!


Actually, the parts manual lists different shim washers to reduce the side float of the camshaft to spec.....  :-[

Offline tbpmusic

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Re: QUESTION FOR cb 350 TWIN ACES
« Reply #7 on: August 25, 2008, 08:08:22 AM »
Actually, the parts manual lists different shim washers to reduce the side float of the camshaft to spec.....  :-[

OK, what is the spec?? I see nothing in the Honda manual regarding an appropriate side play value.
It's irrelevant to start shimming if there is no target.


bill2
"If you can't fix it with a hammer, then it's an electrical problem"

Bill Lane
 '71 CB450 Mutant/ '75 CB200/ '81 CM200/ '71 C70M

Offline Raul CB750K1

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Re: QUESTION FOR cb 350 TWIN ACES
« Reply #8 on: August 25, 2008, 09:48:06 AM »
Hope this helps....

Offline mark

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Re: QUESTION FOR cb 350 TWIN ACES
« Reply #9 on: August 25, 2008, 09:53:13 AM »
Re:camshaft side clearance....
"If the side clearance is excessively large, noise will develop between 5000 to 6000 rpm.... If the side clearance is over 1.0mm (.040"), install 0.2mm shim which are available. The standard side clearance is 0.2~0.6mm (.008~.024")."

1970 CB/CL-250/350 manual, pg. 17.

No mention made about rocker arm side clearance.



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Offline lordmoonpie

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Re: QUESTION FOR cb 350 TWIN ACES
« Reply #10 on: August 25, 2008, 11:28:56 AM »
Re:camshaft side clearance....
"If the side clearance is excessively large, noise will develop between 5000 to 6000 rpm.... "

1970 CB/CL-250/350 manual, pg. 17.

No mention made about rocker arm side clearance.

Well I guess my CB350 was far from standard but it was also a very quiet engine despite the apparent side play in the (Joy) cam....makes sense for a standard engine even though it's not something I've personally seen. ;D
1994 Ducati 888 SP5
1951 Ducati 50cc Cucciolo
1981 Yamaha XV750 SE