Re: valve adjustment woes

Technical Help Forum

valve adjustment woes

Billy 05-22-2008, 6:01 AM
hey guys.

i am trying to adjust the valves on my bike, and have done the left hand side with no issues. the right hand side on the other hand is driving me nuts.

what mark on the wheel do i have to adjust the right side on? TR?

thanks

Bill

Billy from MN

Re: valve adjustment woes

Abes_CW 05-22-2008, 8:29 AM

Billy, TR is right. Remember it will it will hit TR twice in the rotation. I found on mine that the TR was hard to hit on the right stroke, as the flywheel would tend to spin past it easily. It usually takes me 4 or five tries to get it right. Do your cam chain adjustment at the same time, because you do it at the same TR spot.

Darren

Re: valve adjustment woes

Billy 05-22-2008, 10:54 AM
okay i just got back from lunch and did the valve adjustment again. i watched the intake side until they raised up then forwarded to the TR position. set the valve gaps - .003 intake and .004 in exhaust. put the cover back on and started it up.

it is still tapping like crazy but not quite as loud.

what the heck am i doing wrong here.

also are there a bit more detailed directions on adjusting the cam chain tension? maybe thats what the problem is, although i would think the left side would have issues too but its fine no noises or anything ....

sad times indeed.

thanks

Billy from MN

Re: valve adjustment woes

Abes_CW 05-22-2008, 11:26 AM

Not sure what model you have Billy, but as for my GL500, for cam chain, there is a bolt, 10mm IIRC, sticking out of the case just above where the inspection hole is, With engine at TR, loosen the bolt a couple turns, not far!, tap with a mallet and retighten.

As for the valve adjustment. 1) Do it when engine is stone cold. 2) When you set the valves, they should grab pretty tight on your feeler guage. Not "some" resistence, but significant, but not to the point where it binds your guage sliding in and out. Also of course ensure they don't change when you retighten the lock nuts. It took me a couple of tries, the manual isn't to specific as to what "resistence" means. First try I had woody woodpecker between my knees.

Good luck

Re: valve adjustment woes

Billy 05-22-2008, 11:34 AM
tap the bolt with a mallet? excellent. would that adjustment have anything to do with the noisy-ness on the right cylinider? maybe im just leaving too much gap. i am adjusting it at the right point though yes?

awesome.

thanks

Billy from MN

Re: valve adjustment woes

Abes_CW 05-22-2008, 12:26 PM

Cam chain can be a acoustic source yes.

Loosening the bolt allows the spring to push the tensioner against the chain, tightening again locks it in place. Sometimes loosening doesn't free the tensioner from the lock, so the gentle taps with the mallet are to do that job.

You know you are on the right stroke at TR when both intake and exhaust rockers have some free play. You'll be able to wiggle slightly both.

Re: valve adjustment woes

Billy 05-22-2008, 12:34 PM
thats what ive read but in fact that has never been the case. in both spots they appear to be tight.

Billy from MN

Re: valve adjustment woes

DAVID 05-22-2008, 12:47 PM
I have never used the 'one spot does both valves' method. Rotate the crank, when the exhaust just starts to open, set the intake. When the intake just finishes closing, set the exhaust. The only foolproof way to set valves.

82 GL500
81 KDX175
If all else fails, read the instructions

Re: valve adjustment woes

NstyDevil 05-22-2008, 12:52 PM
if they are reallllly loud, then you have the wrong compression stroke. sometimes it takes me at least 2-3 tries to get it right.

i'm still fiddling and figuring out the exact procedure of tightening the bolt without it changing, cause i have found that tightening the bolt will cause the adjustment to be thrown off. as i tighten it down, it will lift the valve thingy, increasing the space.

i remember someone once said that he only tightens it all finger tight, then tighten the bolt which actually worked very well for me last year

__________________

'80 CX500 Deluxe
approx 80k on the odometer

Re: valve adjustment woes

Abes_CW 05-22-2008, 1:03 PM

I made a tool out of a #4 Robertson screw and the cut off scrap of my daughter's hockey stick. The robertson screw is a ringer for the adjusting bolt on the valve. Screw the screw into a stick and viola, a valve adjustment tool. Total cost ZERO.

I've heard robertson screws aren't common in the US, nor hockey sticks....

Darren

Re: valve adjustment woes

Billy 05-22-2008, 1:09 PM
ha! im from Minnesota, which is basically like a mini Canada as far as Hockey is concerned. Im beginning to wonder if my left side isnt too tight then, because it is darn near whisper quiet. does anyone have a recording of a proper sounding engine?

Billy from MN

Re: valve adjustment woes

Abes_CW 05-22-2008, 1:15 PM

There is a trio of sound recordings on Rob Davis' page, accessable from the links tab on the top right of this page.

Warm

Cold

And Cam Chain failured

Darren

Re: valve adjustment woes

NstyDevil 05-22-2008, 1:16 PM
i was about to say, search youtube for cx500 and get alll kinds of sounds

__________________

'80 CX500 Deluxe
approx 80k on the odometer

Re: valve adjustment woes

Abes_CW 05-22-2008, 1:18 PM

links to Rob's adjustment page

http://www.elsham.pwp.blueyonder.co.uk/cx500/tappets_cam_chain/

Warm engine

http://www.wolfteck.com/files/CX500%20warm%20start.mp3

Cold Engine

http://www.wolfteck.com/files/CX500%20cold%20start.mp3

Bad Camchain

http://www.wolfteck.com/files/cx500%20cam%20chain%20rattle.mp3

Re: valve adjustment woes

Randall-in-Mpls 05-23-2008, 11:11 AM

Billy wrote:
ha! im from Minnesota

Where exactly in the Hockey State? If you're in the Twin Cities, come by my place this weekend. We'll put the stethoscope on it, and find out where your noise is coming from.

R

'78 CX500 - The Black Maggot

My mid-life crisis has two wheels.

CX500 Factory Service Manual
(Downloadable by chapter)

Re: valve adjustment woes

Anonymous 05-24-2008, 4:39 PM
I thought you adjusted the cam tensioner at TL which is the left cylinder, am I right or left?

Re: valve adjustment woes

t053376 05-24-2008, 5:27 PM
My manual says adjust the cam chain on the "TL" which the is where the left side valves are adjusted. Someone posted that cam chain adjust done "warm" instead of "cold" is better in that it causes the tensioner to take up more slack on the chain. I found when adjusting my valves that if I tightened the lock nut slightly, then checked the clearance it was slightly loose. I then tighten both lock nut and adjuster nut together to acheive the desired valve clearance. Just my 2c worth!!

tuy_kat

Re: valve adjustment woes

Billy 05-27-2008, 5:50 AM
well it is still clicking.
ive adjusted these things every way possible and all with the same result.
perhaps it isnt the valves after all?

where should i look now?

sounds like woodpecker still.

darn it.

Billy from MN

Re: valve adjustment woes

Anonymous 05-27-2008, 7:02 AM
If the noise got worse after you adjusted the valve, you need to refine the procedure. Otherwise, you might be hearing something else like wrist pin wear or rocker arm shaft wear. How many miles on your bike? I always set the valves a little tighter than other model Hondas. If it was .003" I would make it a tight .003" Not .0035". More like .0027" And yes, it's hard to get the adjustment just right if it changes when you tighten the locknut down. You have to practice it a while and compensate for how much the clearance changes when you snug it down.

Ron in PA

Re: valve adjustment woes

Billy 05-27-2008, 7:12 AM
there is only about 8700 miles on this bike.
unless someone messed with the numbers.
i thought i set it really tight.
i didnt do the TDC method with the marks as outlined on the site.
i did the just opening / just closing method above.

all of the methods i have tried are having the same result.

:(

Billy from MN

Re: valve adjustment woes

Randall-in-Mpls 05-27-2008, 11:13 AM
Billy, where are you in Minnesota? There might be someone close by who can help you out.

R

'78 CX500 - The Black Maggot

My mid-life crisis has two wheels.

CX500 Factory Service Manual
(Downloadable by chapter)

Re: valve adjustment woes

Billy 05-27-2008, 11:47 AM
im in lakeville.
just up the road from the lakeville harley dealership.
theres also the "ghostrider" custom shop, leo's south, and a new moto primo up there.

Billy from MN

Re: valve adjustment woes

t053376 05-28-2008, 8:35 PM
How loud is the woodpecker?? From prev members, it seems that the CX pushrod engine does have some valve train noise at best!!! You can even hear it when manipulating the rockers at TDC compression!! Cam chain ... thats another issue!

tuy_kat

Re: valve adjustment woes

Billy 05-29-2008, 5:11 AM
it is loud enough where one feels quite silly riding the thing. also it instills a sort of "this thing seems like it might blow" kind of fear.
not good.
:(

Billy from MN

Re: valve adjustment woes

kingston73 05-29-2008, 7:44 AM
These aren't great recordings but I'd be interested to know how it compares with your bike. I have also just gotten this and have adjusted the valves twice now, the second time it seemed to make the noise slightly better. I wish I had an old school mechanic nearby who knew what these are supposed to sound like, but I've called around and nobody seems to be familar with the cx's.

http://www.youtube.com/watch?v=Aihx1FHfOnE

http://www.youtube.com/watch?v=njMAJuC4qbk

1979 cx500D/1980 CX500C engine

Re: valve adjustment woes

Billy 05-29-2008, 9:17 AM
as far as i can tell it is pretty much identical.
aside from the "suction" sound on yours it is literally identical. its almost as though there is a ball bearing on the piston or something. or like the spark plug is too long and is hitting it. but when i throw the screwdriver on for a listen its almost impossible to isolate.

at this point i think i may adjust the valves to no gap for a minute and see if the noise still persists.

Billy from MN

Re: valve adjustment woes

Anonymous 05-29-2008, 9:40 AM
When you pull the valve covers make sure all the fasteners holding the valvew and rocker arm assembiles are tightened to the proper torque spec.

Re: valve adjustment woes

Billy 05-29-2008, 10:07 AM
err? where can i find the proper torque spec for those?

thanks

Billy from MN

Re: valve adjustment woes

Randall-in-Mpls 05-29-2008, 11:07 AM

Billy wrote:
where can i find the proper torque spec for those? thanks

In the Factory Service Manual, or maybe in a Haynes or Clymer. I don't get down Lakeville-way very often, but if you want to ride up to Minneapolis on Sunday afternoon, I can give you a CD with the FSM. Or you can download it from a link in this thread, if you have the bandwidth. That's assuming you have a CX500. The GL500/650 FSM is linked in various other threads on the forum.

R

'78 CX500 - The Black Maggot

My mid-life crisis has two wheels.

CX500 Factory Service Manual
(Downloadable by chapter)

Re: valve adjustment woes

Billy 05-29-2008, 11:31 AM
you sir, are a god!
thanks for the link.
grabbin em now.

Billy from MN

Re: valve adjustment woes

LuckyRider 05-29-2008, 8:52 PM
I had some problems with my 78 CX rattling and whenever I adjusted the valves the noise would get a little better but would return aftr just a few commutes. Also, my right exhaust tappet clearance kept opening up and over time was screwed in considerably more than the intake or left exhaust.

I finally decided to tear down to find source and discovered that the thumb pad on the exhaust rocker arm (the part that rides the cam lobes) was worn totally off and the cam chain tensioner was broken. It's a real testament to how robust these things are that it was even still running.

Not to alarm you, but if you can, measure the amount the tappets are screwed in and compare against each other.

Another idea, take the tappets out and examine the bottoms for flat spots. New tappets can still be found although they run about 4 bucks each last time I checked.

Finally, these things do sound a bit like a sewing machine and with the heade haging out there, the noise is not contained under the tank like some other bikes.

Oh and before anyone assumes that the above problems were a result of my bad maintenance practices, I boought this bike off Ebay and previuos owner did disclose that he thought it was nosier than usual. So kudos to him and as always, buyer beware.

Hope this helps,

Regards

Re: valve adjustment woes

Billy 05-30-2008, 12:10 PM
thanks for the advice.

im beginning to doubt that it has anything to do with the valves at this point.

i placed the scope (haha screwdriver) at all points on both heads and they sound almost identical. so now im wondering if its not a pump issue or a fan issue.

an interesting side note, is that during idle it almost sounds like the bike will die, but then it kind of "coughs" and resumes the idle. during some of these "coughs" the engine almost sounds like it will sieze or something. i think this may be carb related though and doesnt really explain the ticking noise. also revving it does not reproduce the "cough" issue.

so in a nut shell, the tick (woodpecker) sounds like it is on the right side (when sitting on the bike) , it goes with the velocity of the engine but doesnt seem to have anything to do with eirther head. i also listened along the bottom of the motor and i cant hear the "thump" from whatever may be causing this noise.

good times.

:)

Billy from MN