Topic: CB550 Project: Valve Adjustement question (after cover removal)

[DKB]

I recently picked up a 1976 CB550 and have been going through the bike addressing the areas that need attention and sorting out some mechanical, cosmetic and performance issues. By far one of the best Honda's I've owned to date and a blast to ride. I've got 2500 miles logged in the past two months and have seen more of the NE this past summer than last 9 years combined;)

Work completed so far:

-Tune Up. Points, Timing, Valve Clearance, Carb Sync, etc...
-Replaced Spark Advance Mechanism
-Replaced Coils
-Carb Cleaning, Rebuild and Vacuum Sync
-New front and rear Dunlop K-70's
-Front Brake Master Cylinder conversion (Used a more modern Kawasaki ZX6 MC with great results)
-Installed Yamaha Titanium Drag Bars
-Replaced Tail light assembly
-Replaced front and rear turn signals
-Restored Tach and Speedo gauges



After about 2500 miles of riding and working through some tuning and odd ball issues, I noticed I was weeping a bit of oil from the front of the valve cover gasket. I picked up a replacement gasket and got into the swap yesterday afternoon but ran into a problem. I was told to loosen up all of the valve adjustment screws in order to provide a bit more clearance while reinstalling the cover with the new seal in place. I quickly realized after bolting everything back up that I lost track of which valves should be open/closed at which compression stroke as all of the adjustment screws are loose and I can't tell which ones to adjust at what point.

Is there an easy way to confirm what cylinder is at TDC and what valves should be open / closed at TDC for each cylinder? I searched the forums but could'nt find the needed info and was wondering if someone could point me in the right direction.
 

[super pasty white guy]

you can either use a feeler (piece of solder, etc) down the spark plug hole to feel when the piston rises, or slightly tighten the adjusters and just feel for when the valve opens and closes.

spwg

[Duke McDukiedook]

The Honda manual should tell you this info, did you check that?

[DKB]

"you can either use a feeler (piece of solder, etc) down the spark plug hole to feel when the piston rises, or slightly tighten the adjusters and just feel for when the valve opens and closes."

Thanks so much for the info! I'll give it a try this afternoon when I get home.

Just to verify, At TDC for each cylinder, should both the intake and exhaust valves for that clyinder be open to .002/.003? If that's not correctcorrect, what is the proper sequence? I know it's a novice question, but this is the first time I've had the valve cover off and am starting my tappet adjustments from scratch. Used to just remove the tappet covers, rotate to TDC, and find the adjusters that were slightly loose...

[DKB]

The Honda manual should tell you this info, did you check that?

I have the CB500/CB550 Manual and the Honda Shop Manual and did not see the specific info in either. I used them to see how to disassemble and reassemble the cover after replacing the gasket but can't find any info on Valve adjustments after the tappets had been backed all the way off...

[BVCB650]

Just put it on TDC, and look at #2 exhaust valve/tappet. It may be up on the cam lobe and not on a flat part of the cam. If it is, you need to rotate the engine another 360* untill it is on the flat of the lobe. #1 intake and exhaust valves will be able to be set either way, but #2 exhaust is where it will be too tight if it is off by 360*.

[DKB]

I just found this info in the Service Manual in the maintenance section.

Cylinder 1 TDC

Cylinder 1. (intake and exhaust)
Cylinder 2. (exhaust)
Cylinder 3. (Intake)
Cylinder 4. (None)

Cylinder 4 TDC

Cylinder 1. (none)
Cylinder 2. (Intake)
Cylinder 3. (Exhaust)
Cylinder 4. (intake and exhaust)

Are these the valves that can be adjusted at each TDC position? For example, while at TDC for cylinder 1, I should adjust both the intake and exhaust valve on cylinder 1, the exhaust on 2, Intake on 3, and nothing on 4?

Can I use the screwdriver / piece of solder in the spark plug hole and just turn the engine and watch for #1 and #4 pistons rising to determine which Cylinder is at TDC?

Sorry to be dense- just want to be sure I've got this right and am not going to cause any damage...





                       

[BVCB650]

You will be adjusting one of the valves on every cylinder, and 2 on one of them. Best to take your points cover off and go by the timing mark.

[DKB]

Thanks for the assist. It was easy enough to figure out what position the engine was in using the screwdriver in the spark plug hole method. Made all the adjustments via timing marks as usual and was done in under 15 minutes. Valves are set and double checked and the bike is up and running quite well. The new valve cover gasket seems to be working out fine and appears to have addressed the oil leak. I appreciate the help and info!