changing cam chain- maybe guides. tips?

Ok so Im considering changing my cam chain. can I change the guides doing the "walk around" gig? I'm thinking no. What am I up against? Bike runs great but the cam chain is a little loose now, and dont seem to get any difference by adjusting it. the mileage is now almost 39K (almost) so I figure that chain has gotta be stretched its a little noisy (so is the clutch but Im rebuilding that too)
So.. is this a PITA job?

 

Doing a Cam Chain replacement is tricky.

It's a good idea to have a quality Chain-breaker and Riveter.

Having an Assistant (or two) to:
a) Feed the New Chain
b) Collect the Old Chain
c) Turn the Crank while you guide the New Chain down-in, ... while the Old Chain is pulling-in and around, ... your New Chain.

You need to Break the Chain.
Fasten the NEW Chain to the Old one, ... so it makes the trip without ANY chance of the splice coming undone.
The Crank will need to be turned to move the chain through.

When the New Chain is threaded-through and emerges with the Splice, ...
You have to JOIN the Opposing Links and Install the Link-Pin and Expand the end of the Master Link joining pin -- Permanently.

Consult a proper Manual.

http://www.motorcycle-superstore.com/2/ ... &zmap=4893

 

It's not that big of a deal, but it is an endless chain. You'll need to "break" the old one and re-rivet the replacement. It's a bit of a PIA; I wouldn't do it because you think it needs to be replaced, check it. Use the same test you would with a drive chain; if you're unsure of the technique say so and I'll explain.

Depending on how tightly your POs (since the bike was new) overtightened the cam chain adjuster lock bolt, you may have a stuck adjuster. Honk on the bolt hard enough and it puts a 'divot' in the shaft enough for it to bind.

Pull your cam chain tensioner, take it apart, and inspect the guts. See if there's a big "gronch" in the shaft from the adjuster locking bolt. If there is it can be cleaned up with a small sharp file.

You'll also want to use a flashlight and an inspection mirror to inspect the front and rear cam chain guides and be sure they're still intact.

***Note in regard to what Rick said*** You need to be VERY CAREFUL turning the crank with the camshafts disengaged from the chain but still in place; these are "interference" engines. I would recommend the camshafts be REMOVED for the process; then you can't bend a valve.

Also, he's correct in that you need a chain breaker and riveter to do the job.

 

After closely reviewing your initial Post, I see that there is just 39,000 miles on the Bike.

Under normal conditions, the Cam Chain is good for nearly 60,000.

If you have a Manual Chain Tensioner; you should consider replacing it for an Automatic Adjuster and initiating a Manual Slack Removal procedure.

 

Cool Im gonna be pulling that tensioner off later on tonight. I wondered about that. And Ill pop the valve cover off and look at the guides with the mirror trick, good call on that.
thanks guys, Ill report back after I check everything over.

 

So let's take the question one step farther....I was getting ready to check some valve clearances on an X engine that I just got. I know NOTHING about the history of this engine. there is a catch somehow and I can't turn it all the way over, only about half a revolution or less (by hand).

It feels like something is catching behind the alternator area, but I don't know. That's just where is seems to be. I have the engine sitting on my bench at stomach height so it's easy to see and feel.

I just noticed the cam chain tensioner is missing. so, I pulled the valve cover...... chain loops over cam sprocket closest to carbs and then heads back down, not going over cam sprocket at front of engine. Guess I gotta broken cam chain.

Can I get a new one in w/o splitting the case? Or do I have a boat anchor on my bench?

Dave

 

dont boat anchor it bro. If the engines already on the bench its a candidate for becoming a NEW engine! and you got frames. I wish I had your toy box!

 

I just found out that I'll be able to inspect it w/o splitting, and as long as there's not other major issues inside, I'll be able to get a new chain on. May have bent valve issues due to the chain but I won't know that til I work my way in to there.

I won't anchor it, I just wanted to know if a broken chain is coronary for an engine or if it is replaceable without having to split. If It HAS to be split, well then so be it. I just don't wanna if I really don't hafta.

 

Some things you just have to take a face value.

The Plant won't turn a Full Revolution.
Upon examination you found the Cam Chain parted.
I'd guess a Valve or two got whacked.

Pull the #1 Plug
Run the #1 Piston down to half-stroke -- paralleling all four Pistons at Mid-stroke.

Using a Open-end Wrench on the Camshaft Flats, ... see if each Cam can be made to complete a revolution while paying close attention to the actions of each Valve Bucket.

You might not have to do much wrenching if you find one stuck down.

 

Dave; getting the new chain engaged with the crankshaft sprocket may present a bit of a challenge, but you should be able to "fish" it without even dropping the sump if you're lucky.

Are you sure the chain's broken/damaged? Or did some other mechanical failure cause it to get "spit" off?

 

I am assuming the chain is broken because it is only over one cam sprocket. Comes up one side, goes back down the other. I guess it is POSSIBLE that someone put a really short chain on and didn't know they had to go over both cams? lol

I'll probably pull head and jug today to take a peak.

Dave

 

I was thinking more that it's simply "derailed" on one side.

 

SKW,

Changing the t-chain seems intimidating until your done.
Then you wonder why it seemed scary to begin with.

Have on hand; a buddy, mirror soyou can see inside the case,
I bought an extra master link and it proved useful as we dropped
the first one and one post got bent fishing it out. That's with
rags in place but sh%t happens.

A magnet on a telescopic rod or long wire (best to have both).

Long, long needle nose pliers.

And a strong bright flashlight.

The cams, sprockets, crank will all line up perfect just take your time and
be patient.

 

Well, I was hoping I'd be able to get away without having to do major disassembly. I lucked out!

So, I pulled the front cam off since there was no chain over it. Then I tied the chain section that was coming up over the rear cam sprocket so I wouldn't drop it somewhere. I pulled the valve bucket assembly, and all the valves look good and not are bent. So, I pulled the head, all chambers look really good, Piston tops look good, not sign of any impact in there. So I pulled the jug. Pistons all look good, rings are nice and free, no scoring on the walls.

So I pulled the rear chain guide out. Now I can see down inside with a tiny bore scope/light that I have. Everything is nice and clean.

So here's what I DID find.....
-rear chain guide top was broken off.
-cam chain is perfectly fine, not broken just installed wrong
-NO SHIMS under the buckets (MaximX)
Must be someone was harvesting shims, broke the rear guide, and didn't take the time to put both cams back into the loop.

Whew.....thought I'd have to do a lot of work.

While things are apart, I'm looking at rings. I measured ring gap...it measured at .023" I don't have a manual for the X. Does an X-pert know the range for ring gaps?

Thanks,

Dave F

 

Sounds like you lucked out Dave.

The ring endgap limit for the X is .040" for top and second ring and .060" for the oil rings.
SO, you should be good.

I'd recommend you hone the cylinder slightly to deglaze them and get the rings re-seated when you get it running.
Try to get a nice cross-hatch pattern but don't take much meat off the cylinders.

@ skw > I'd think the cam chain is probably ok. As mentioned before, make sure the tensioner is working correctly and maybe the guide is worn too.

 

Thanks for the help. Will be emailing you with some other questions later.

Dave

 

Turns out the chain guide is not broken, either. So, I have the engine all apart simply because someone harvested the shims and didn't put the chain back over the second cam.

So, slight adjustment to plan.....gonna hone the cylinders, lap the valves, reassemble with all new gaskets.

Then comes the fun of shims......I'll have to stick an assortment of shims in, then assemble the whole top, do the math, then take the top off again to do the shims. Gonna hafta to this the long way, I guess. Fortunately the engine is on the bench.

Oh, yeah.......gonna re-paint the jugs while it's apart.

Dave F