Can't reinsert tappet?

[chep]

I've been searching around the internet for a good place to ask about this, and this forum seems like my best bet. So hi.

I bought a 1981 GS450L for cheap a few months ago knowing that the timing of the cam chain had to be adjusted after the previous owner had tinkered with it a bit and had eventually given up. I picked it up as a little learning project as I've had little experience with anything mechanical and I really want to get into such things (motorcycles especially).

I've wanted to do everything properly from the start, so I picked up the right Clymer manual from my local library. After surveying the bike, manual in hand, I was ready to set the timing right, which didn't seem extremely complicated. However, just before I started I looked at the exhaust ports and noticed that the threads in the head to attach the exhaust flange were all messed up. So I removed the head and had a machinist fix it. He did a great job, and now I've got everything to put the head back on.

Before handing over the cylinder head I removed the four tappets (are they called tappets?) because they kept sliding out. I carefully noted which went where and set them aside. After getting the head back, all have gone back in with ease except for one.

Here are some pictures of the head and tappet in front of me:

The tappet in question only goes in a few millimeters and gets stuck. It simply will NOT move in farther. I noticed (visible in the last picture) that there is a ring looking metal piece about as far down as the tappet will move. I've noticed that I can move that metal ring with a small screwdriver, but no position of the ring will allow the tappet to be reinserted. Is that ring in the way? Has this happened to anyone else? Can it be resolved?

If you need more information or better pictures, just ask. I'll have access to a better camera shortly.

Any help would be MUCH appreciated. Thanks.

 

[Guest]

Hi, Not sure what you are calling a ring? I am thinking you are seeing something at the od of the valve spring retainer? Or, are you looking at the valve keepers at the valve stem? There should not be anything that would be interfering with the bucket fitting back in the bore. Were the valves removed or are they as installed by the factory? The bore is a pretty close tolerance fit and if the bucket is a bit askew it will hang up sometimes. Don't try forcing anything, but if there is nothing in there that shouldn't be, I would try spinning the bucket as you try to lower it into the bore. Ray

 

[TeamDar]

The valve stem is below the keepers. There is something seriously wrong. It looks like a bent or broken valve, guide, and or spring. The valve must be removed to investigate.

 

[chep]

@Ghostgs1
I only used the word ring because it looked like that to me when I saw it. Is it a spring? I haven't removed any valves, but I guess I can't say the same for past owners... I can say, for whatever it's worth, that the bike ran very well until the past owner messed up the cam chain timing in his tinkering.

I did figure that a gentle twist helped the other three buckets slide back in, but this last one will NOT move past a certain point.


@TeamDar
That can be done. But when you say serious... does that make it a potential project-ender for an inexperienced guy like me?

 

[tom203]

Will another bucket fit OK in that spot, i.e. switch them around? Roll the suspect bucket on a smooth surface, like plate glass, granite countertop, etc.- does it behave oddly?

 

[TeamDar]

Do you not see that the valve stem is forced down below the keepers? Look at the other valve stems.....even if you got a bucket to go in the bore it would make contact with the retainer before the valve.

 

[chep]

@tom203
I rolled it like you said. It rolls as smoothly as I've ever seen anything roll. I briefly swapped two as you said. The bucket in question fits into other bores, but no other bucket will fit into that bore.

@TeamDar
I'm looking at a diagram to try and follow you. The valve is sticking up through the center, right? And the retainer is bigger and makes contact with the spring below it?

 

[rustybronco]

Chep, More than likely the bore the tappet slides into is damaged. I had the same problem on one of the tappet bores on my 850. I removed the valve and polished the bore where I found a 'witness' mark showing where the bore had gotten damaged.

As TeamDar suggested, the valve must be removed to investigate.

 

[chep]

Thanks guys. I'll remove the valve and see what I find.