Valve adjusting

Technical Help Forum

Valve adjusting

Blindstitch2002 07-12-2008, 12:15 AM
I am going to do a valve adjustment one of these weekends and I was reading how to do it over at the Rob Davis site and it was saying to find top dead center by putting the bike in top gear and rotating the tire. Another site I read to take the radiator cover off and use the bolt up there to rotate the crank.

Which method do you prefer and are there any things that I should watch out for.
I guess now I have a reason to buy a torque wrench.

1978 Honda Cx500 Maggot
1979 Honda Cx500 Custom
1980 Honda Cx500 Deluxe Couch Project Bike

CX500 Factory Service Manual
Courtesy of Randall-in-Mpls

Re: Valve adjusting

Connella08 07-12-2008, 12:45 AM
its alot easier to use the rear tire in 5th gear to move the pistons. what i did was put it in last gear, tapped the started a few times untill i saw the piston coming up (i pulled the plugs out) and use the rear tire to fo fine adjustments. its much harder to use the radiator removal method because you have to drain it, remove it, then you have to put it back on and refill. you kinda have to jerk the tire foward sometimes to get it to move. or you can sit on the ground straddling the tire or crouch behind it and use the "spokes" to pull up on.

Re: Valve adjusting

LRCXed 07-12-2008, 1:11 AM
If it's the bike in the avatar, all you need to do is take the 2 screws out of the bottom of the radiator that holds the black plastic grill on, and drop it out of the way. Pull the plug out and use a 17mm bolt with a short extension on it and use it to turn the motor. It's a lot more precise since you can turn it and have your finger in the plug hole to feel when the piston comes up on the compression stroke. Pull the other plug out of the back cover of the motor and line it up with the TL mark on the fly wheel and your ready to adjust the valves on the left cylinder. Do the same for the right side looking for the mark on the flywheel of RT for that side.
.004 for the exhaust and , .003 for the intakes and your good to go. Take your time and try to get the same resistance pulling the feeler gauge thru on both valves of each intake and exhaust. If you take the gauge out of the set, you can put it under both rocker arms at the same time to see if the feeler gauge pulls out evenly from under both rocker arms. Both valves are opened by the same rocker arm, so try to get them as even as you can.
Good luck, it's a simple procedure. Just be patient and take your time.

If your going to do something, do it right, don't do it half as@*d.
http://globalcxglvtwins.hostingdelivered.com/

Re: Valve adjusting

Blindstitch2002 07-12-2008, 1:46 AM
Thanks guys.
Any advice on a torque wrench. Never had a reason to get one till now. I am not a fan of broken or stripped bolts.
I always used my own rule. If the bolt was small and thin use a 1/4 drive ratchet. If bolt is huge and thick use 1/2 drive or better.

Last time I saw someone use a torque wrench it was one of those that has the moving needle (All Manual) and the guy bent it into a U shape. I am pretty sure that one isn't accurate anymore.

1978 Honda Cx500 Maggot
1979 Honda Cx500 Custom
1980 Honda Cx500 Deluxe Couch Project Bike

CX500 Factory Service Manual
Courtesy of Randall-in-Mpls

Re: Valve adjusting

PWG in Lowgap NC 07-12-2008, 3:33 AM
My opinion. (I use your wrench size method) If you feel you must use a torque wrench, get the kind with a long pointer and the guage near the handle that actually shows the bend of the wrench shaft..

http://httassociation.com
82 GL500 / 66 MGB Trike "Old Yeller"
05 Suzuki S50 "Plaything"

ANY WARM DAY ABOVE GROUND IS A GOOD ONE
(unknown senior citizen)

Re: Valve adjusting

fll1441 07-12-2008, 5:42 AM
I agree, using the bolt on the front of the crank to turn the engine works well. Keep in mind that the TL and TR marks align twice during each cycle. Make sure you have the piston in the correct position by verifying all four rockers are loose and/or checking the spark plug well.

Another member made a tool to hold the square end of the valve adjuster while tightening the locknut. He used a square drive drywall screw and a cabinet knob. I had both laying around the garage. So I also made one. It worked great and made it much easier to tighten the locknut without the adjuster shifting. Basically, it is a homemade version of the tool Rob has pictured on his website.

I have had good luck with a bar type torque wrench I bought at Sears. It's the type Phil described in the post above. I haven't stripped or broken anything since I got it. It's simple to use. But, it's the only torque wrench I have ever owned. So, I don't have anything to compare it with.

1982 CX500 Custom

Re: Valve adjusting

Daniel45mpg 07-12-2008, 7:56 AM
I just bought one from Sear for $15. It's the kind with the Pointer on the end.
Craftsman Torque Wrench 3/8-in sq drive Beam type 0-75 ft/ib part # 44690
i think the ratchet type is C$#p. or at least the one i had was.

1980 CX500C
1980 CX500D

Renew, Reuse, Recycle.

Re: Valve adjusting

Shep 07-12-2008, 10:28 AM

Daniel45mpg wrote:
I just bought one from Sear for $15. It's the kind with the Pointer on the end. Craftsman Torque Wrench 3/8-in sq drive Beam type 0-75 ft/ib part # 44690 i think the ratchet type is C$#p. or at least the one i had was.

The problem I've found with the Pointer type Torque wrenches as that after time they become inaccurate but they are better than nothing.I prefer the better,"Click Stop" ones.A good one may cost more but will last a lifetime :)

New Global CX/GL Forum,
http://globalcxglvtwins.hostingdelivered.com/

Re: Valve adjusting

LRCXed 07-12-2008, 11:35 AM
I agree with Shep, the click type torque wrench is much more accurate and the lower settings are easier to achieve with them. You set the setting you want, and when you achieve the proper torque, you feel a click in the handle. I just called Harbor Freight Tools and they said the 1/4" is $28.00, the 3/8" is $20.00 and the 1/2" is $20.00 also. I bought a 1/2" one a few years ago, and knowing some of their stuff is not the greatest, I took it to a local speed shop that has a torque tester for these. Mine was only off by 2 lbs on the week side. So for the price, you can't beat it. Much better than trying to read the needle while your pulling on it.

If your going to do something, do it right, don't do it half as@*d.
http://globalcxglvtwins.hostingdelivered.com/

Re: Valve adjusting

audi-4kq-t 07-12-2008, 12:48 PM
I literally just finished doing the tappet adjustment. i noticed two things while i was doing it. one, the TDC notations on the flywheel were not as listed in the above mentioned informational website; and two, when i went to do the manual cam-chain adjustment, the bolt would not turn two full turns out. I was kinda confused by both of these things. Anybody know why this was?

Anyway, I would say that it was a relatively easy job and well worth doing on your own.

By the way, I didn't use a torque wrench while doing the job, i just made the bolts "1/4 inch tight".

Andrew

Re: Valve adjusting

LRCXed 07-12-2008, 1:28 PM
Where were you checking for the TL and TR markings? I have to use a flash light to see it inside the inspection hole. Under the right side carb in the back cover of the block is where the inspection plug is that needs to be pulled out to see the flywheel and the markings. As was mentioned above though, you need to pull the plugs and feel that the corresponding piston is at TDC to line it up at the correct stroke!

As far as the cam adjustment, The bolt on my sons cam chain adjuster had been tightened up so tightly in the past that it smashed the metal of the adjuster down and would not allow the spring to pull the cam chain adjuster to tighter against the chain. I had to file the slot open to let it move freely. You might have had someone in the past tighten yours down to tight and strip the threads, but most likely it's corrosion between the case housing and the bolt. Rust can develop on the bolt head and bind it to the aluminum in the housing. Squirt some rust buster type of penetrating oil in and around the bolt recess and let it sit over night. Squirt a little in there a couple times to ensure it's saturated. It should let it free up. The bolt will not come out all the way with the engine cover on.

If your going to do something, do it right, don't do it half as@*d.
http://globalcxglvtwins.hostingdelivered.com/

Re: Valve adjusting

audi-4kq-t 07-12-2008, 1:57 PM
I did pull the 17mm inspection plate and alligned the markings. the markings for the left hand cyclinder were correct (FL / TL). If i remember correctly, the markings for the right hand cyclinder were FR and LR or something of that sort. I checked for movement in both sets of rocker arms, whick it did have. I would assume that I was at TDC for the right cyclinder and therefore should have been at TDC for the left cyclinder..

As far as the cam chain adjustment, i didn't really have any trouble backing off the tensioner adjustment bolt but it would only back off about 1 and 3/4 turns before it stopped running out. I am not terribly worried about it, as i did a check the tensioner spring and it was taught. I was somewhat suprised though, seeing as everyone says that it should be backed off two turns.

Re: Valve adjusting

LRCXed 07-12-2008, 2:24 PM
You have to make sure the cylinder your working on is at the COMPRESSION stroke. As mentioned above by fll144, the flywheel mark for the piston your working on rotates past the mark twice. On one of the alignments of the mark, it will be the top of the exhaust stroke and the exhaust valve rocker arm will be opening the valves. On the next alignment of the mark, the piston will be at the compression stroke. That is where you want to be to adjust the valves.
As far as the cam bolt goes, 1 3/4 turn is OK. They are just saying that it has to be backed off far enough to release any tension on the cam adjuster to let it move freely when you tap on the case to get it to move in tighter.

If your going to do something, do it right, don't do it half as@*d.
http://globalcxglvtwins.hostingdelivered.com/

Re: Valve adjusting

larryb22 07-12-2008, 2:38 PM

I pulled the valve covers and watched for the intake valves to start to close. Then slowly aligned the TDC for the side I was working on. I did the right side first. On my 82 GL500 Interstate, I did not have to remove or even touch the fan shroud. I could get the inspection plug out and a socket plus extension on the crankshaft bolt to turn the engine over. I tried the back wheel method and found it a pain in the butt trying to see the flywheel marks and turn the back wheel.

Larry

1971 Moto Guzzi Ambassador. SW Michigan.

Re: Valve adjusting

Blindstitch2002 07-12-2008, 6:17 PM
When adjusting the cam chain adjuster does the engine have to be at a specific postiion. TDC?

1978 Honda Cx500 Maggot
1979 Honda Cx500 Custom
1980 Honda Cx500 Deluxe Couch Project Bike

CX500 Factory Service Manual
Courtesy of Randall-in-Mpls

Re: Valve adjusting

the cheese 07-12-2008, 7:05 PM

Yes, it has to be at the TL mark. On the compression stroke for the left side. Make sure you have slack in both EX. an IN. valves. Lossen the bolt 2 turns and give it a slight wack with a rubber mallet. It will take up the slack in the chain. Tighten bolt. Done. You do not want the tensioner to take up slack in anyother position.

I prefer to turn the crank bolt on the front motor. Gives you better control. The tire method is also harder than it should be.

Michael

1981 CX500 Custom
Just say no to skin graphs, wear your gear!

Re: Valve adjusting

dtimm612 07-12-2008, 9:07 PM
To audi, the crankshaft on these bikes are off-set so when one piston is TDC the other will NOT be. Both cylinders valves sets can not be adjusted at the same flywheel position

81 Silverwing GL500
84 Magna VF1100C (V65)

Re: Valve adjusting

Anonymous 07-12-2008, 9:40 PM
sorry, I should have been a bit clearer in my last post. i did turn the crank (as per directions) for the left and right cylinder valve adjustments. I had slack in the intake and exhaust rockers on each side after necessary TDC adjustments. It was a long day in the sun laying body filler and sanding. I was kinda out of sorts when i posted last.

As far as the cam chain adjustment bolt only backing out 1 and 3/4 turns. Do you guys forsee there being any issue with this? I did a check of the cam adjuster spring and it seemed to be taught. I couldn't reach the chain to confirm that there was no slack.

Thank you,

Andrew

Re: Valve adjusting

t053376 07-13-2008, 9:59 AM
On my 82 CX Custom, the cam adj bolt will only back out 1 3/4 turn also. I took the advice on this forum and lightly gave my socket a rap with the hammer. I guess it may free the tensioner if it is binding. If i remember correctly, the manual says to do this with the left cylinder at TDC compression. Although recommeded to do when the engine is cold, I adjust while the engine is somewhat warm. I may stand corrected but I think that a warm cam chain is looser than a cold one allowing the tensioner to take up more slack!

tuy_kat

Re: Valve adjusting

Blindstitch2002 07-20-2008, 2:31 PM
Ok just finished doing my valves and taking a ride. Since the site was down I printed off the instructions at http://www.elsham.pwp.blueyonder.co.uk/cx500/
And went at it. Not to hard but it leaves me with some questions.

Do you guys remove your tank when doing it like the site does or leave it on?

I also used the bolt under the inspection cover to rotate it because turning the rear wheel in 5th gear is a laugh. I am sure it works for someone just not me.

The PO of this bike must have just did the valves before he parked it in 1984 because the intake was .009mm and the exhaust was .010mm.
But I undid the setting to put them at intake .010mm and exhaust .012mm like the site suggested. Now I have a ticking going on.

Should I tighten them down a bit more or live with the tick?
I made sure the feeler was in snuggly but could still be pulled out.

The reason why I ask is now since I know how to do it the process is going to be a lot more simple and I have an odd adjustment screw on one out of the 8 screws that I think is nearing being stripped out. So I am going to try and order a new one.

Anybody know how much they cost?

Ok so 3 questions again.
1. Tank on or off?
2. Should I adjust them a hair smaller with the feeler gauge to remove the tapping?
3. How much do they cost to replace?

1978 Honda Cx500 Maggot
1979 Honda Cx500 Custom
1980 Honda Cx500 Deluxe Couch Project Bike

CX500 Factory Service Manual
Courtesy of Randall-in-Mpls

Re: Valve adjusting

hakko808 07-20-2008, 3:22 PM
I found that I achieved better results if I applied slight pressure on the rocker over the pushrod to take up the slack in the rocker asembly. I recall reading here that the adjusters do not wear flat which can cause some adjustment issues.

Re: Valve adjusting

LRCXed 07-20-2008, 4:15 PM
Hay Blindstitch, I have a few extra NEW adjuster screws left from a bulk sale a few years ago. If you Email me your address, I'll send you one.

My manual says to adjust the exhaust to .004 and the intake at .003 while the chosen cylinder is at TDC in the compression stroke. I'm going to have to go look at the site you added to your post! Your #'s seem really loose. What year is your bike?

If your going to do something, do it right, don't do it half as@*d.
http://globalcxglvtwins.hostingdelivered.com/

Re: Valve adjusting

dtimm612 07-20-2008, 4:41 PM
Keep in mind Blindstitch is taking mm and the numbers you posted are in inches (intake would be 0.08 mm or 0.003 in)

81 Silverwing GL500
84 Magna VF1100C (V65)

Re: Valve adjusting

fll1441 07-20-2008, 6:30 PM
Blindstich, I also have a custom and do not have to take the tank off. I'm guessing that the larger standard tank may block removal of the valve covers.

I have the same problem with the tappets being loud when the clearances are properly adjusted. But, I'm resisting the temptation to tighten the clearances. I'd rather listen to the tapping, than burn a valve.

1982 CX500 Custom

Re: Valve adjusting

Blindstitch2002 07-20-2008, 7:00 PM
fll1441
I envy you. Noises that I know aren't completely natural drive me nuts. I almost convinced myself that the valves were my radiator noise. Then I kicked myself and said if I go so far as take the radiator off to check I better have a fan to put on. I don't want to burn any valves either but I like things right and the more I can do the more I will know.

I figured the guy that wrote to take the tank off somehow set himself on fire several times doing it.

1978 Honda Cx500 Maggot
1979 Honda Cx500 Custom
1980 Honda Cx500 Deluxe Couch Project Bike

CX500 Factory Service Manual
Courtesy of Randall-in-Mpls

Re: Valve adjusting

Blindstitch2002 07-20-2008, 7:18 PM
I just went to search out my manual to figure out what I should have adjusted them to and guess what. The girlfriend cleaned the house and I have no idea where it went. It was by the couch. Guess I have to wait for her to get home from work to second check myself. The one i downloaded online says
In .08mm or .003
Out .10mm or .004

Really wish I would have known that before I started. Practice makes perfect. When the replacement tappet gets here I will fix my mistake.

Thanks LRCXed

1978 Honda Cx500 Maggot
1979 Honda Cx500 Custom
1980 Honda Cx500 Deluxe Couch Project Bike

CX500 Factory Service Manual
Courtesy of Randall-in-Mpls

Re: Valve adjusting

Ayal 07-20-2008, 7:23 PM
Hi Blindstitch, Thanks for all the postings you did on other items.
I followed the Hynes procedure when I did my valves, with advice from a friend... I did not meet this site then yet.
The Hynes says to remove the tank if necessary, I did not need to (79 CX500 C)
I did rotate with the rear wheel but I would try something else next time, as this was difficult and took a long time to get the position accurate.
For a following noise, I put a cooking wooden spoon, spoon side flat to your ear and tip of (long - 18") handle to each 4 points where I know the valves are. It's possible to hear when the motor is running just which valve is clicking. One may have loosened up if not tightened enough.
For torque wrench, nowhere on this bike did I need over 80 Lb/In that I've seen so buy the more sensitive one. Cilick or handle? I bought the cheaper one, with handle and dial. To get the right gap says my friend, tighten gaps so that it's actually difficult to pull out the gap gauge. To modify from manual recommendation, I asked a garage owner and the answer was to follow the manual number to the tee, for best perormance. Good luck.

Strive to learn something new every day

Re: Valve adjusting

Blindstitch2002 07-20-2008, 7:33 PM
Ayal
Next time you try do it from the inspection port under the radiator. It is really easy. I picked up the Harbor Freight torque wrench click type for $15 and it seems to be working ok. Hardest part is waiting for the click. I might just have to try this spoon trick. They all pretty much seem to be chattering and why shouldn't they since they are .004mm off being correct. Might be a tomorrow job to atleast correct my error. Maybe I should buy another manual too.

1978 Honda Cx500 Maggot
1979 Honda Cx500 Custom
1980 Honda Cx500 Deluxe Couch Project Bike

CX500 Factory Service Manual
Courtesy of Randall-in-Mpls

Re: Valve adjusting

WisconsinCX 07-20-2008, 8:12 PM
Blindstich...if you need that hardware feel free to lift one off that old 78 untill yours comes in. Let me know.

83 650 Silverwing Interstate Phoenix
81 Deluxe
80 Custom
78 Maggot
83 CB1100F yeah baby!!

Re: Valve adjusting

Blindstitch2002 07-20-2008, 8:18 PM
Is the Cx still in West Allis? I attempted to drive the bike up there in the rain yesterday and some idiot cut me off on Loomis and then stopped dead in the road. I was hoping it was some old nursing home excapee but it turned out to be a kid.

1978 Honda Cx500 Maggot
1979 Honda Cx500 Custom
1980 Honda Cx500 Deluxe Couch Project Bike

CX500 Factory Service Manual
Courtesy of Randall-in-Mpls

Re: Valve adjusting

WisconsinCX 07-20-2008, 8:19 PM
No, up in Menomonee Falls now. The guy needed it out of his driveway this morning.

It's gracing the parking lot at work.

83 650 Silverwing Interstate Phoenix
81 Deluxe
80 Custom
78 Maggot
83 CB1100F yeah baby!!

Re: Valve adjusting

Blindstitch2002 07-21-2008, 7:18 PM
Well I re-adjusted the valves today except the broken tappet that looked not so straight and then turned into two pieces. This time i did the job with the tank and everything else on and it worked pretty well. So now I am waiting for a tappet to get here and moving on to replacing the radiator fan and sanding down the tank to remove the bad clearcoat.
Maybe I will even get around to putting on new throttle cables.

1978 Honda Cx500 Maggot
1979 Honda Cx500 Custom
1980 Honda Cx500 Deluxe Couch Project Bike

CX500 Factory Service Manual
Courtesy of Randall-in-Mpls