Broken valve spring?

[Steve]

Excuse my ignorance but is the head gasket the valve cover gasket and the base gasket the one below - between the crank and the cylinders? Also are there any special tools that I would need to remove valves, seals etc.? I have watched the video on valve installation on BassCliff's site so I know about the C-clamp and cut out PVC pipe. I assume I can use the same set up to remove the valves but is there anything else?

As Salty Monk mentioned, starting at the top is the breather cover, which has a gasket. That is the T-shaped piece that's about 5x7 inches and has a hose coming out the back that goes to the airbox. Next is the valve cover and its gasket. The valve cover is the large H-shaped cover that you see sticking out under the edges of the tank. The valve cover is just over an inch high, and you can see its gasket quite easily. Next is the head. The head is what contains the spark plugs and valves, and also has the ports for the carbs and exhaust pipes. The head gasket is just below those ports. The cylinders are the finned areas below the head, and the base gasket is at the bottom of it.

Any time you remove the head, there is a very good chance that you moved the cylinders in the process, and it was probably just enough to disturb the seal, so it's good practice to replace the base gasket, too.

Glad you liked the video, my son and I had fun making it. I only showed putting the valves back in, but you can use the same tool to remove the valves, too. It will be quicker, since you don't have to fight the keepers in the process of taking them out. To remove the seals, find something with a lip on the bottom, reach under the seals and pull up. They simply slide into place, but after many years of heat cycling, they will be rather stuck.

Whenever I have taken valves out, I tend to use a bit of lapping compound on the valves. Just a light application will show you the seating area. If the valves are still in decent shape, this will show up very quickly as a nice narrow band of polished metal.

The only "special" tool you might need is a torque wrench to re-install the head, but you should really have one of those anyway. Torque values are relatively low, about 27 lbs-ft, so a decent 3/8" drive wrench will do nicely.

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[razooki]

Any time you remove the head, there is a very good chance that you moved the cylinders in the process, and it was probably just enough to disturb the seal, so it's good practice to replace the base gasket, too.

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Steve, are you telling me that I have to tear the engine apart just to look at the valves? 'Cause that's what it sounds like to me. Remove the head to check the valves but then remove the cylinders just to replace the base gasket?

[Steve]

Steve, are you telling me that I have to tear the engine apart just to look at the valves? 'Cause that's what it sounds like to me. Remove the head to check the valves but then remove the cylinders just to replace the base gasket?

Yep. If you don't tear it apart, the only part of the valve you will be able to inspect is the tip that the bucket pushes on to open it.
If you are simply wanting to check the clearances on the valves, you only need to remove the valve cover and the ignition cover on the right end of the crank.

If you are also wanting to change the valve seals, you will have to pull the head, as you need to be able to squeeze the springs to remove the keepers and the valves.

Yes, since you will most likely bump the cylinders in the process of removing the head, change the base gasket. If you don't, you might see a leak from the base gasket, and I don't want to be around to hear the language when you find out that you have to take it all apart again and put it together with new gaskets, just because you did not want to take another half hour to do it right the first time.

There are times that I find it amusing that some of us that have experienced a procedure and have tried to relate that as a learning experience, but are met with doubt by those who think they know a better way. I'm not saying this is you, Raz, but I'm sure you have seen it many times on here, too. The most popular 'short cut' is dropping the float bowls and spraying the parts you can see, then proclaiming that you "cleaned the carbs". After taking the carbs out again (and again), you start to believe some of what we write.

OK I'll get down off my soapbox now.

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[SqDancerLynn1]

I would bet you have a broken spring..You can stuff some rope into the cylinder to hole the valve up.To enable you to replace the spring. BUT you should remove the head and have all the valves and springs check. You can swap parts around & reinstall the cam and check the clearance. If the clearance is still very large ? definately would have a bent valve.
Your call !!!

[razooki]

Steve, I'll be honest I have my doubts but something tells me you must have learned this the hard way at some point in the past!! I'll post my findings when I dismantle the head - with pictures of course.

Thanks again,

Raz

[razooki]

Yes, since you will most likely bump the cylinders in the process of removing the head, change the base gasket. If you don't, you might see a leak from the base gasket, and I don't want to be around to hear the language when you find out that you have to take it all apart again and put it together with new gaskets, just because you did not want to take another half hour to do it right the first time.

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I took a closer look at the repair manual and I just want to make sure I get this straight. I think I know what you're talking about now Steve. If I get this right the cylinders are 'sandwiched' between the head and the crank and are held in place by the nuts on top of the head right? So if I remove the head I won't see another set of nuts holding down the cylinders. That is why if I remove the head the cylinders will be 'loose'.
But then if my assumption is correct if I remove the cylinders won't I need a tool to re-insert the pistons?

[Dogma]

I did it this spring on that same engine. You can use hose clamps as a ring compressor. The only really challenging part is getting the gasket surfaces clean.

Well, that and wrestling cylinders and pistons. Put the bike in gear (I liked 5th) to get control of crank rotation. Start with #2 & 3 pistons high. Get them into the cylinders. Turn the rear wheel slowly until #1 & 4 meet the cylinders. Make sure the pistons go into the bores straight. Lay a board across the engine case to hold them up and straight as they enter the cylinders. The weight of the cylinders and some light pounding with your fist will be enough to drive the cylinders over the pistons. Once the pistons are in, the cylinders will just fall over them, so watch out for that.

Don't force anything. It's easy to break rings, damage pistons, etc. Think it through, follow the instructions, be patient, don't be afraid to start over. It took me several tries, though I'm sure I could get it in one now.

Vesrah base gasket and o-rings will leak oil. We have a few documented cases around here.

[Steve]

I took a closer look at the repair manual and I just want to make sure I get this straight. I think I know what you're talking about now Steve. If I get this right the cylinders are 'sandwiched' between the head and the crank and are held in place by the nuts on top of the head right? So if I remove the head I won't see another set of nuts holding down the cylinders. That is why if I remove the head the cylinders will be 'loose'.
But then if my assumption is correct if I remove the cylinders won't I need a tool to re-insert the pistons?

You are right, the cylinder block is just sandwiched in there, there are no other retainers, once you pull the head.

As Dogma mentioned, you might use hose clamps, but I have found fingers to work the best. The bottoms of the cylinder liners are tapered a bit, which makes it easier to funnel the rings into place. One of my three manuals had the suggestion to make a tool to hold the pistons in place while lowering the cylinder block over them, I am attaching a picture from the manual. You need to make two of these guys. Put them under pistons 2&3, lower the block until the rings are ready to slide in the bottom. By reaching around the piston, you can squeeze the ring in and allow the cylinder to come down just a bit. It helps a bit to have a helper for this part. You will have to alternate sides, dropping one side at a time, but you will soon have all the rings in both cylinders. Pull the forked blocks, rotate the crank, squeeze the rings into the outer cylinders.

Here are the blocks:


I have found the dimensions to not be too critical. The overall width needs to fit between the cylinder studs. The slot needs to straddle the connecting rod. The overall length needs to straddle the hole, but be short enough to pull it out, once the cylinder is in place.

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[razooki]

Thanks Steve, this will definitely come in handy.

[razooki]

There's nothing wrong with my valves!! I just took out the head and when I turned it over to look at the valves I notices that the #2 exhaust valve was being held open by the tip of the zip tie I used to measure the valve clearances!! As soon as I removed it the valve closed. I guess it could have been worst so I'm not too upset. I've never done this before so it was a few hours well spent.

I had to take the plastic chain runner out to remove the head so any tips on how to put it back? Also, the gasket had some liquid gasket around the opening for the chain. Is that necessary?

Thanks,

Raz

[Nessism]

There's nothing wrong with my valves!! I just took out the head and when I turned it over to look at the valves I notices that the #2 exhaust valve was being held open by the tip of the zip tie I used to measure the valve clearances!! As soon as I removed it the valve closed. I guess it could have been worst so I'm not too upset. I've never done this before so it was a few hours well spent.

I had to take the plastic chain runner out to remove the head so any tips on how to put it back? Also, the gasket had some liquid gasket around the opening for the chain. Is that necessary?

Thanks,

Raz

Sounds like you took off the head for nothing. Didn't you notice the head of the zip tie was broken off when you extracted it? Oh and sealer on the cam tunnel O-ring is not recommended.

[razooki]

Sounds like you took off the head for nothing. Didn't you notice the head of the zip tie was broken off when you extracted it?

No.

Oh and sealer on the cam tunnel O-ring is not recommended.

There is no O-ring just the liquid gasket. Should there be one?

Any tips on putting back the chain guard?

[Steve]

Any tips on putting back the chain guard?

Chain guard or chain runner?

The front guide (runner) for the cam chain simply slides into place. Just make sure it's seated correctly so the top is flush with the cylinder block.

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[Nessism]

You need new gaskets when installing the head. Some of the newer type head gaskets are made from multi layer steel and do not use a rubber seal around the cam tunnel. In either case, no need for gasket goop anywhere on the head gasket.

[razooki]

Thanks Ed & Steve. One more question. Since the head is out I would like to take a look at the valve seals. The PO replaced #4 piston but I'm not sure if he did anything to the valve seals. I bought the bike right after he did this so the engine has not run for any extended time but when I did have it running it was blowing some blue smoke on deceleration (from what I've read it is indicative of bad seals). Is this normal with a 'fresh' engine? If I remove the valves & springs can I take a look inside to check the seals? I really don't want to change them if they are OK (I know they're inexpensive but as someone once said "If it ain't broke, don't fix it").