cam timing / CCT change help
 

alright - i have read every thread that i can find on here about cam chain tensioners and timing. i also have the factory service manual.

here is my current situation: i had a front cylinder CCT failure at idle speed on the street. with a lot of clanking noise, i sputtered off the road and shut down immediately. i replaced both cylinders CCT sucessfully. as i did so, i assumed (and we all know where that gets us) that it did not skip timing as the engine ran fine immediately following the failure. now after reassembly, cranking the engine still produces a pretty loud "clanking" sound. it will run, but it is not smooth or quiet. i am only to assume that it did skip timing (slightly - probably one tooth) and the noise that i hear is the valves lightly striking the top of the piston.

here is my dilema: i obviously need to check timing on both cylinders to not have anymore assumptions. there are a few very detailed threads on the board that explain how to check timing in several different ways. the understand them all and feel very confident in checking myself. the area that i need advise or assistance in is correcting the timing issue once i find out where the problem is. if someone could let me know the:

a) proper procedure for changing cam timing
b) what parts need to be removed to access the area to accomplish work
c) if any special tools are needed

my experience with removing the gas tank and airbox to access the front CCT was pretty easy. i am imagining that there will be more signficant tear down to access chains/sprockets. just let me know as much detail as you can about engine position and such to properly modify timing.

thank you so much!

From the UK site....

VTR CAM TIMING PROCEDURE
WITH BOTH FRONT CYLINDER AND REAR CYLINDER CAMSHSHAFTS REMOVED ( Starting from scrap)
1) Turn C/shaft until FT appears and lines up with the mark on the cover
2) Fit FRONT CYLINDER Exhaust camshaft with the mark FE on the exhaust camwheel level with the c/head and at the front of the bike with the cam chain tight - RIP TIE the chain to the wheel
3) Fit FRONT CYLINDER Inlet camshaft with the mark FI on the camwheel Level with the C/head and to the rear of the bike - RIP TIE the chain to the wheel
THE CAM LOBES WILL NOW BE POINTING AWAY FROM EACH OTHER
4) Fit the cam caps and CCT - CUT THE RIP TIES
5) TURN THE C/SHAFT ANTI CLOCKWISE 270 DEGREES until RT appears and lines up
6) Fit REAR CYLINDER Exhaust Camshaft with the mark RE on the camwheel level with the c/head and at the rear of the bike with the cam chain tight - RIP TIE chain to wheel
7) Fit the REAR CYLINDER Inlet cam with the mark RI on the camwheel level with the c/head and pointing to the front of the bike -RIP TIE chain to wheel
THE CAM LOBES WILL NOW BE POINTING TOWARDS EACH OTHER
8) Fit cam caps and CCT - CUT THE RIP TIES

I had the same thing happen. You are gonna hate what comes next but it has to be said. You really need to have your valves checked on that cylinder now. I spun my motor over with a wrench and it was fine, when i used the starter i got the same clanking you talked about in your post. I made the mistake of timing everything and putting it all back together just to find out that i bent both exhaust valves.

Remove your valve covers to check the timing marks. If it has skipped a tooth you re-set it by removing the cam caps and disengaging the chain (don't let it fall into the sump). You then put it back in the right spot and reinstall cam caps and then the CCT. Only basic tools are needed to do this.

If you have got it wrong the first time, do a compression test to check if you have a bent valve before you start pulling the head off.

more cam timing help
 

does anyone have any clever techniques for disengaging the cam chain to adjust / correct timing issues. i have removed both valve covers and successfully retimed the rear exhaust cam by 1 tooth by just pull up on the cam chain hard enough to get enough slack in it to forcibly skip the sprocket against the chain to correct the timing.

the front cylinder is a different story all together. the intake cam is out of timing by almost a 1/2 a revolution. i would like to be able to completely disengage the the chain, rotate the sprockets to the correct position and then re-install chain. i need some help doing that as i cannot produce enough slack to pull it off. my first thoughts are to either remove the sprocket from one of the cams, make all adjustments and reinstall - or - to totally remove one cam shaft and sprocket unit from the head, make adjustments and reinstall.

anyone with clever, timesaving tricks let me know. i wish to be able to just disengage the chain without disassembling anything further. let me know!

Take Both Tensioners Out And Use Your Finger To Put Tension On The Chain(thats Enough To Line Up The Cams).the Front Cams Always Look Like There 1/2 Tooth Off.even If Your Cct Let Go On Idle ,the Exhaust Valves Are More Than Likley Bent!weve Had Guys Come Into The Shop That Didn't Put The Cylindars On The Timming Marks When The Changed Cct,and Bent Valves Without The Motor Runnig.IF YOU HAVE ANY ?'S GIVE ME A CALL 1-920-734-3363

You probably already know this, but remember:
a) 2 revs. of your crankshaft = 1 rev. of the camshafts
b) Because of this you may not be at TDC when you see FT or RT in the window. This is why you have to check the marks on the cam sprockets; you may have to rotate the crank another 360 degrees to line up the marks.
c) Back off the tension on the CCT for the cyclinder you are working on & lock it down.
D) If you are at TDC at that cylinder & the CCT tension is relieved, you should be able to just pick the camchain up by hand & rotate the camshaft by hand easily. Just use a straight-edge (ruler) laid across the cylinderhead to make sure your marks are lined up properly, because it's kind of hard to just eyeball it.

OK, So I got my new CCT's from APE last Friday because with 30k on the odo I know I was way passed due. Now I'm scared to do it myself with every thing I've been reading here. I am mechanically inclined but not as good with bikes as I am cars.:) My question is isn't their a link to do this step by step? I have searched this site and a few others with out finding a step by step, only bits and pieces. Anyone............Anyone.........??????
Thanks. :confused:

The Honda shop manual covers how to checking the timing on the motor. It also covers valve adjustments, which pretty much tells you step by step how to do everything asked in this thread about installing the APEs when replacing the stock CCTs (with exception of adjusting). (There is no right answer for the adjusting from what I know, although there are a few methods in other threads. I measured and adjusted for 1/4" slack in between the cams, and had to back off half turn afterward)

Read through the Honda manual about adjusting the valves (read it few times), and you have all the info you need.

I also believe if you look around a bit, you might find a downloadable manual out there (I don't condone this, but they are available).

J.

Afraid there's not that one end-all-be-all post. Even the best posts I've seen have mis-stated some aspect of the process.

The place where most people mess-up is the Cam Chain jumping timing because they are not at TDC. (My hand is raised.)

First: get the Honda or some other manual.

Second, realize that the manuals don't emphasize how utterly important it is to make sure that the cylinder you're working on is at TDC. Just because you have indexed the FT or RT Mark thru the Inspection Window does NOT mean you are at TDC. You have to pull the Valve Cover off to verify that the Marks on the Cam Sprockets are positioned properly as specified in the manual BEFORE releasing the tension on the CCT spring.

If you do this, then it is pretty easy. I did my back one wrong the first time, but fortunately realized it before putting everything back together & starting the bike.

This weekend I did it too, I set the RT mark through the window, removed the rear valve cover, zip tied the pulleys together instead of zip tying the chain to the pulley. Well I pulled the cct out and boom the chain slipped, I watched it happen! I was able to back the mcct out enough(once installed) to manually lift the chain off the pulley teeth and rotate the engine just enough for the chain to skip a tooth, I'm off to buy the manual which I should have done first! I have pictures of the procedure throughout.

I did rotate the engine in a full rotation and is it possible that I bent a valve by manually turning over the improperly timed valves???? I didn't turn it over twice just once.

-Jeromy

Unless you felt/heard contact between pistons and valves you're okay. The motor would also suddenly be very difficult to turn due to the interference.

i'm goin in, cover me!!!
 

did it all wrong the first time, now am attempting to right the ship!
how do i measure valve lash? want are the torgue settings for valve cover
and cam journals?

Without the manual, you're pretty much doomed! Unless you've got an experienced Honda mechanic standing next to you, that is.

When mine skipped, I got mucho resistance after about half a revolution when trying to rotate the crank. That's what told me i had messed up. So i stopped the operation & "phoned a friend". Made sure i thoroughly understood where the cam lobes, valves & pistons were during each cycle (4 stroke) before proceeding.

Tdc
 

if i can see the top of the piston and the flywheel marks are aligned, this must
be TDC? no?

The flywheel marks will be aligned for both the top of the compression stroke (tdc) and the top of the exhaust stroke.

It's best to reconfirm the tdc on the other cyl. If you have the rear cyl torn down you can look at the front cyl. The front FT marks should align with the cam lobes all pointed up-and-out. From that point turn the crank 270° CCW until the rear RT marks align and you will be at 'rear TDC'.
If you have the front cyl torn down use the rear to confirm its TDC (RT marks aligned and cam lobes pointed up-and-out). From that position turn the crank 450° CCW until the front FT marks align on the crank. That will be the 'front TDC' position.

Ok, Check this out....Just got the manual...

TDC is set on the rear cylinder. The RT is shown in the window and per the manual, the two cam chain pulleys are aligned with the top plane of the head. RI on the right RE on the left, The lobes are facing upward and inward, not as you describe up and out. pg 8-23 on the honda manual. I'm off to pull the front head cover and see what it says for alignment.

cam timing help
 

i do understand the compression and exhaust strokes for a 4 cycle engine and all the details of why the pistion is at TDC twice during a cycle ... blah, blah, blah. my major problem is that i cannot get to the stroke that i need to turn the engine to because the timing is off so bad that i get valve contact with the piston that prohibits the crank from turning further. my need now is to disengage the cam chain from the cam sprockets, return the crank to the appropriate TDC, realign the cams, reinstall cam chain onto cam sprockets, reinstall CCT, do compression check, prey for no bent valves - and ala-kazam - a new functioning SuperHawk!

with the CCT completely removed for the front cylinder, i cannot pull enough slack in the cam chaing to adjust the cam sprockets. i can forcibly make the intake cam sprocket move 1 tooth at a time - but it is under pretty high pressure that i do not want to place on the system since i have to rotate it almost 1/2 a revolution. i cannot move the exhaust cam at all. i have removed the guide from the top of the cam chain but still cannot produce enough slack in the system to disengage the chain from the sprockets. it gets right up to the very top of the teeth, but doesn't have the extra 1/100th of an inch it needs to slip off. the manual says to remove the stays and take the entire cam assembly out. my thought is to leave the cams in the their place since all this is torqued down, remove just one sprocket from either cam, disengage the chain easily, rotate the engine, reallign the cams, reinstall the cam sprocket in the correct position already engaged in the chain while tightening bolts that hold it to the cam - and then - compression check, etc - see if there is further damage.

anyone with helpful input or experience - please throw in your $0.02

pull the actual cam off with the pulley still attached and rotate it that way, that's what i did.

me too!
 

me too! pulling cam is the only way, unless your chain is very stretched!

yep - remove the cam caps - pull both cams (with sprockets attached) and replace them in position.

deflection?
 

after reading posts here and taking into account the vague instructions from
APE, i am assuming that being super anal about the deflection is not necessary! ? feedback welcomed!

So here's what it looks like so far, I'm having a bitch of a time removing the front head cover. I busted my 10 mm deepsocket on removing the cam bolts. after moving the radiators out of the way and the oil cooler, It requires a deepsocket and an extension to remove the top two head cover bolts.

I'm trying to attach the photo's...another try.

Bent Exhaust Valves On Noisy Cylinder ----been There --pull Heads Port For More Power Jeff

frnt clyndr cover
 

comes off easily if you pop the carbs up and pull the splash gaurd.

what does TDC mean? thx

Top Dead Center, the point of the stroke of the piston where the piston is at its highest point. On the compression stroke, all valves will be shut.

Finished the mcct install and the complete pair removal while I was down there, fired her up. Turns over easily! Thanks god initial thought. Won't start...Shit, oh, I forgot to turn on the gas. Cool.

It started! Sounded great, super tight!! Ran for about 30 seconds and died, so I got down and backed the front tensioner out 1/4 turn, did the same with the rear, Heard some chain slack kinda like when the tensioners sound bad, motor died, re-started and it ran but died again, now It won't start. WTF? I'm pretty sure it wouldn't have skipped a tooth with the tensioner installed as it was, I guess, I'll have to check compression to see if it's even at both cylinders. Can somebody assist me from here maybe?

I'm focusing on the pair emissions now:
Everything appears to be as written on gregs site. So on the front carb, right side there's a T-fitting in back of the carb throttle pulley. I had it vented to the air, should this be vented or not? I have the hose plugged now Like gregs site says. Coming from the carbs I have two vented hoses, and two more hoses going to a tee and it's blocked off(or should this be left vented since it's the one that went to the charcoal cannister?), I have the two 1/8th caps on the front intake manifold. Airbox plugged and everything else yanked. sounds right yea?

Ever get it started? I can only suppose that you got the petcock vacuum line hooked up in the wrong spot. It should go to the rear of the petcock, not the bottom nipple. Also, ensure the petcock is ON. Unless you heard bad sounds just before or as the bike died, I think this is a fuel issue.