V65 Cam chain tensioner replacement

[texas-ss-tornado]

From the Honda V-4 forum:

Be very certain to drain the block of all coolant by removing the drain plugs in the front of the block.  It is also important to loosen all of the head bolts and retorque them in a cris-cross pattern inside to outside.

A shortcut for the cam chain tensioner replacement. Do one head at a time.
If you dont want to remove the alternator cover, some people put the bike
in 6th gear and rotate engine as needed using rear wheel.

1. Pull the valve cover off.

2. Remove the front camshaft only. We wired the chain to the
the rear sprocket and used a sharpie to mark the chain and sprocket
in the front. This makes it easier to relocate the chain on the sprocket.
Might not be a bad idea to mark a cam ear also to avoid putting the cam
back in 180 degrees off.

Do not rotate engine until camshaft has been put back in.

3. Remove old tensioner.

4. Replace the small pin in the NEW tensioner with a bent coat hanger
so that you wont drop the small pin down the cam tunnel. Do not make
the inserted piece of hangar to long or you wont be able to remove it once
the tensioner is installed.

5. We DID NOT replace the tensioner tower bolts. We used some very complicated
algorithms (we guessed and prayed) to tighten the tower bolts securely when putting the new tensioner in. We never did find torque specs for those bolts.

6. Clean the ears and sprocket threads so loctite will bind properly.
    Torque the sprocket bolts BEFORE reinstalling the cam holder on the right side or you wont have room for the wrench.

Once buttoned up the engine was noisy at first but settled down and seems to run well.

[texas-ss-tornado]

Cam holder off

[texas-ss-tornado]

Cam out:

[texas-ss-tornado]

Sharpie Marked Sprocket and Chain.  Also shown wired but you dont have to do that if you use the sharpie marks.

[texas-ss-tornado]

Hangar replacing original wire that came installed in new tensioner.  Again, dont make the piece going into tensioner any longer than necessary.

[texas-ss-tornado]

Red Arrow indicate guides you need to be sure to clear when putting the tensioner slipper/band down in tunnel.

[texas-ss-tornado]

Side by side shot of old vs. new tensioners.
Note how short the new one is and the different angle
of the tensioner rod as a result.

[texas-ss-tornado]

Much easier to only remove one cam isn't it.  Replacing one tensioner tower at a time is really the only way to do it, unless you have to send your cams out for reworking, then you don't have a lot of choice.  Any bolts where the torque specs are not listed use standard torque values for metric bolts, a quick google search will find them.

[TLRam1]

Look in the Magna FAQ and there are specs for Torque, just not your bike, might be close though.

Did you DL the V65 Service manual? It may have the specs.

[texas-ss-tornado]

Look in the Magna FAQ and there are specs for Torque, just not your bike, might be close though.

Did you DL the V65 Service manual? It may have the specs.

Yep, I have downloaded the service manual, printed out Chapter 10 on cylinder head/valve, has the torque specs too!!!

[TLRam1]

There is an "oil mod" where you drill holes somewhere, maybe in the cam holders?? If this is easy to do while apart you might check into what is suppose to be done to see if this is phisable to perform at the same time.

[texas-ss-tornado]

There is an "oil mod" where you drill holes somewhere, maybe in the cam holders?? If this is easy to do while apart you might check into what is suppose to be done to see if this is phisable to perform at the same time.

Too expensive ($300) and not worth it in my opinion, I've had probably 3 dozen V65's over the years and exactly (1) known cam failure on an 83 model, so I will take my chances. 

[texas-ss-tornado]

By the way, whose bringing the feeler gauge? 

Valve Clearance Adjustment

Dave Dodge Method
Over the years I have developed a method of adjusting the valves on V-4's that is accurate and quick. The crank and rotor position is the same using the rotor TDC marks. Make sure that the cylinder you are adjusting the valves for is on TDC compression stroke. On the rear cylinders the cam lobes will be pointing AWAY from each other, and on the front cylinders the lobes will be facing UP and slightly towards each other when the particular cylinder to be adjusted is at the correct position.

Loosen and back off the adjusting nuts on the intake and exhaust rockers. Place a .003" feeler gauge between the cam lobe and rocker arm. Snug down the adjusting screws (with your fingers) until each screw just touches the valve tip, then move the feeler gauge back and forth to make sure there is drag (not tight/not loose) and tighten the nuts with a wrench. Now recheck the clearance at the valve with a .005" feeler gauge. The feel should be a snug .005" or a loose .004". Re-adjust the screw if you don't get this feel on all four valves. Use same procedure on remaining three cylinders.

There is a 1.5 to 1 rocker arm ratio, so .003" at the cam gives you a snug .005" at the valve. This procedure reduces the risk of uneven rocker adjustment. Once you get the feel of a snug .005" clearance, you will find you have proper setting for long cam life and minimal (if any) clatter.

IMPORTANT: I always torque the adjusting nuts to 15 ft-lbs. Tighten the nuts with a wrench enough so they wont come loose, then rotate engine until rocker arm depresses valve about half way. This will allow room for the torque wrench and the pressure against the adjusting screw will keep it from turning while you are torqueing.




Robyn Lander's Method
Robyn Landers has an illustrated, step by step guide at: V4 Valve Adjustment.




Rotating the Cams
Rather than tediously lining up the timing marks, you can reconnect the wiring plugs that you disconnected while removing the heat shield and rear cylinder cover, so that the starter motor will work. Flip the kill switch so the engine won't actually start, then blip the starter so that the cam lobe on the *opposite* end of the camshaft you're working on is at full lift.

The cam profiles on the Magna/Sabre are not very radical, so you have a fair bit of leeway as to where this occurs. Now, on the end of the camshaft you're working on, install the special tool. Both ends of the camshaft are now being pressed up against the camshaft holders, so the camshaft won't be tilted. The long flat feeler gauges are flexible enough to be easily bent to ensure there is no binding when testing the clearance. ("Bent" doesn't mean putting a sharp crease in them to make an angle, just pressing down a little to curve it so that it goes straight in between the adjusting screw and valve.)

Use two gauges at once, one under each side of the follower. When the clearance is correct, the gauge should be moveable with a slight drag, whereas the next size up should not go in at all, unless you really force it, in which case you're fighting against the valve spring. Even after carefully setting the valve clearance, there may still be a little audible ticking, especially before the engine fully warms up.

As related on Robyn Landers's web site, some later engines had the cam bearings line bored. These can be identified by half-circle plugs in the heads where the boring tool went in. Clearances on these engines are tighter so supposedly you don't need the special tool to adjust valve clearances. You can check out valve noise with an automotive stethoscope, or the poor man's substitute: a long screwdriver held with the tip pressed into the hex socket in the head of the rocker shaft and the other end pressed against your ear.