Unable to get timing chain over both cams

stafebak · June 12, 2012, 05:18:11 PM

Hey all, just finishing up my head gasket replacement and I am stuck on what I thought would be an easy part. When I took the chain tensioner out, there was enough slack that I could get it on and off with relative ease...however now that I am re-installing everything I am stumped...There is a solid 1-2 inches that one of the cams have to move to get in to it's slot, but the chain will not allow that. I've got the rotor (I think?) RT mark on the front like the repair manual says, and can't find any way to get any more slack out of the chain. I looked down with a flash light and it doesn't appear to be stuck on anything. The tensioner is still out, and the front chain guide is sitting in correctly as well. I tried installing the exhaust cam first, and the intake cam first, it doesn't make a difference...

What am I missing here? I would really appreciate your help, as this is all that is stopping me from riding this summer.

Thanks!

merlinq21 · June 12, 2012, 05:49:35 PM

The chain must be kinked down there somewhere. If you remove the cams and move the crank while holding the chain taught, does the crank move normally? If not the chain is kinked. I have a motor sitting on the garage floor right now. Separated the head from the lower cylinder to find out where my chain was caught, found a dowel from the cam journal sitting between the chain and the teeth of crank gear. I would suggest that you pull the head off again and work the chain free.

The chain did not shrink so it has to be caught up somewhere. Good luck

stafebak · June 12, 2012, 06:01:10 PM

Ah hell. I bet you're right...because I did lose a dowel down there. Do you think I would be able to get at it from the bottom? I remember inspecting from the top and couldn't see a damn thing.

merlinq21 · June 12, 2012, 06:11:43 PM

you might be lucky, but it is very difficult to do so, you will need a magnet and flash light and lots of patience. I can be done, but what ever you do not force the crank you will damage the chain, the dowel and the crank.

I was able to pull both of the dowels I dropped in there by taking the head and the lower cylinder apart. In my opinion, this is the only way to know for sure that you got the foreign objects. It is a real PITA but in the long run it is the only way to know for sure.

I was told by a machine shop that you can move the crank counter clock wise slowly to un kink the chain - as long as you have tension on the chain. Get a magnet on a piece of copper wire or one of those telescoping magnets and start fishing, it could take hours.

Try that first, if you have to pull the lower cylinder off the bottom end, I have been told you will have to hone the cylinders and maybe replace the rings. I have not had anyone confirm or deny that step.

stafebak · June 12, 2012, 06:32:24 PM

Thanks for the help...my little brother has access to a video snake (I think they're called? the little snakes with a camera and light on the end) hopefully that will help...I did already do some turning counter clockwise with tension...hopefully I didn't mess anything up...ugh. I checked to see if I got lucky in the oil pan, and nope, nothing. Thanks again.

Dizzledan · June 12, 2012, 06:38:10 PM

A fiber-optic cam? That's pretty cool. You should be able to find it for sure with that. Drain the oil (if it isnt) so that it wont float around while you're fishing for it.

If you take the jug off and you're gentle with it, I don't see how you would need to replace the rings/hone the cylinders (maybe just a recommendation from your mechanic). Someone told me that you should replace the head gasket whenever you pull the head off.

Paulcet · June 12, 2012, 08:18:57 PM

Quote from: stafebak on June 12, 2012, 06:01:10 PM
Ah hell. I bet you're right...because I did lose a dowel down there. Do you think I would be able to get at it from the bottom? I remember inspecting from the top and couldn't see a damn thing.

Wait. You dropped a dowel pin in there and then kept trying to put it together?

If so, you get what you deserve. Not trying to be a jack ass, it just comes natural to me.

stafebak · June 12, 2012, 09:03:18 PM

I was about 90% sure I dropped it down in to the pan, hence why I continued to put it back together. Apparently not. Obviously you get what you deserve, who doesn't when it comes to stuff like this? It's not like I was saying, this is bullshit, I can't believe this happened to me. When you know you're at fault for something, don't you love when people rub it in your face. Lesson learned, without your snarky comment.

Anywho, I don't think it's fiber optic, but it functions the same, and they are pretty inexpensive these days, he got his for around 120, but got a discount through his work. So I guess I'll take a peek down there and see what damage I've wreaked. Hopefully none, but I doubt it. /life

adidasguy · June 12, 2012, 09:08:12 PM

They sell those cameras at Costco. I got one there. Has 3' of stuff and an extension for longer. It fits into a spark plug hole. They're fun! I explored Junior's engine when it went out, until I discovered it was the counterbalance bearing. Cool to look in the cylinder and other areas of the engine.

Dizzledan · June 13, 2012, 05:50:31 AM

Quote from: adidasguy on June 12, 2012, 09:08:12 PM
They sell those cameras at Costco. I got one there. Has 3' of stuff and an extension for longer. It fits into a spark plug hole. They're fun! I explored Junior's engine when it went out, until I discovered it was the counterbalance bearing. Cool to look in the cylinder and other areas of the engine.

You guys should make a video, this sounds really cool.

Stick one up your nose Adidasguy, see if there's a brain up there

adidasguy · June 13, 2012, 11:22:39 AM

Quote from: Dizzledan on June 13, 2012, 05:50:31 AM
Quote from: adidasguy on June 12, 2012, 09:08:12 PM
They sell those cameras at Costco. I got one there. Has 3' of stuff and an extension for longer. It fits into a spark plug hole. They're fun! I explored Junior's engine when it went out, until I discovered it was the counterbalance bearing. Cool to look in the cylinder and other areas of the engine.

You guys should make a video, this sounds really cool.

Stick one up your nose Adidasguy, see if there's a brain up there

Will do! There must be a brain mixed in with all those boogers - somewhere.

Then I'll mail it to you and you can stick it up your butt and see if there is a brain up there. Double back at ya!

stafebak · June 13, 2012, 07:02:10 PM

Well...I found what was holding the chain, somehow the chain guide was. I was able to get the chain on both cams now easily...and scoped out the inside with the cam and couldn't find a dowel anywhere...so I'm wondering if it fell out the bottom and I didn't notice. I don't hear any metal clinking when I crank by hand and it does seem to crank freely. I'm still scared though.

Tombstones81 · June 13, 2012, 07:05:59 PM

^^ dont go ANY further until you find it!!!

Seriously!

I've gone through a TONNNN of headaches and still am from multiple reasons.

and let me tell you from experience, you Do Not want something breaking that was 100% avoidable.

merlinq21 · June 14, 2012, 04:29:57 AM

I agree, it needs to be found. It could be catastrophic for the bottom end of the motor and the rider. Regardless of where it is, you need to find it.

If you do not want to remove the upper and lower cylinder head, you will need to pull the oil pan. From my experience it will be difficult for the dowel to make it's way into the oil pan on it's own.

I would break down the motor and find it. Having said that; you will need two complete gaskets, the head gasket and the lower gasket, new orings to seat in the head gasket, 8 new washers (copper to sit between the head nuts and the head and one new dowel pin.

This is a PITA job, but you will have peace of mind after the rebuild. If you don't find it then, you will need to take it a shop to split the casings or have a go at it yourself.

The dropping of the dowel pin cost me 800 for a new motor.

Good luck

News:

Unable to get timing chain over both cams