Valve Bucket Hard to Spin / Large Clearance (Intake Valve)

[cboling]

Hello again everyone. I have searched and read through some other posts with similar problems as I think I have. I bought a well neglected GS a couple of months ago knowing it wasn't running and that I would have to do some maintenance / rebuild work on it. So far, so good if I can only keep from having any more bolts break on me. I think the previous previous owner had stock in Red Loctite!

Anyway, I have slowly been putting the top end back together (covers, gaskets, and such) and today I decided to check the valve shim clearances again. Below is what I found: (yes, I know I need the correct measuring tools. Those are coming next week.)

Left Intake:
Clearance < .04
Shim ~ .25 /.26

Right Intake:
Clearance .65 (just a snug fit)
Shim - Originally .25 / .26 (Swapped with Right Exhaust)
Shim - Now .28 / .29 (Did not notice change in clearance after re-check.)

Left Exhaust:
Clearance >= .15 < .18
Shim - .25 / .26

Right Exhaust:
Clearance < .04
Shim Originally .28 / .29 (Swapped to Right Intake)
Shim - Now .25 / .26 (Did not notice change in clearance after re-check.)

The problem I have noticed is that the right intake bucket does not turn like all the others. It is very tight and I can tap a screwdriver against the slot to get it to turn. I have read that it could be removed easily enough but I guess I don't exactly know what I am looking for. The guy I bought the bike from indicated that he replaced an intake boot (or maybe both) and that I might want to look at the head more closely. I did not notice anything wrong with the valves  when I had the head off but not really sure I know what I am looking at.

At this point, I haven't even had the engine running. It is timed correctly (which i did recently after removing the head for the exhaust bolt repairs.)
I can turn the crank at the bolt easily and all of the valve buckets move well and look to move the same distances. (even with the spark plugs in place. which makes me wonder about the compression?)
If the boot was bad and the bike was run for any length of time, what kind of problem would notice or should I be looking for?

Should I just continue and try to get the engine running as is or should I remove the cams again and pull the bucket if possible and check things out further?

Any suggestions are greatly appreciated.

[beRto]

Right Intake:
Clearance .65 (just a snug fit)
Shim - Originally .25 / .26 (Swapped with Right Exhaust)
Shim - Now .28 / .29 (Did not notice change in clearance after re-check.)

Left Exhaust:
Clearance >= .15 < .18
Shim - .25 / .26

Wow. These two are way out of spec!!!   

Are you turning the engine over before the recheck? If not, there will be some oil buildup under the shim and this may be why you are not noticing a change in clearance.

The problem I have noticed is that the right intake bucket does not turn like all the others. It is very tight and I can tap a screwdriver against the slot to get it to turn. I have read that it could be removed easily enough but I guess I don't exactly know what I am looking for.

This sounds like a problem. I think gsJack snapped a valve in cold weather because of a tight bucket. Search for related posts from him.

[cboling]

Yep. Before checking each clearance, I turn the motor (via the crankshaft bolt) and have the cam lobe opposite the shim face. I have checked them a few times to try and verify that the bucket was moving with the cam lobe and it seems to be pushing the valve down properly.

Thanks,
CB

[tt_four]

Yep. Before checking each clearance, I turn the motor (via the crankshaft bolt) and have the cam lobe opposite the shim face.

I used to do that and apparently it's not correct. If you're on the right side of the bike and are spinning the engine by the camshaft bolt, you want to look at the very ends of the (what are those two called? the ones with those lobes on them?), well there's a mark on the end of both of those shafts that are directly over the valves. When the two lines point straight to eachother you measure I believe the right exhaust, and both intake valves, then spin it again so they're pointing away from eachother, and check the left exhaust. I could have those completely mixed up, but they show you which ones to do in the right order in the front of the service manual. If you have no idea what I'm talking about I'll actually look in my manual when I get home and explain it better.

[cboling]

Thanks TT_Four

I will try that later today if the rain holds off and maybe that's all it is. I am still concerned about the bucket being tight / not spinning freely but, if the clearances are better by turning the camshafts the proper direction, then I won't worry too badly.

CB

[cboling]

So I decided to try and beat the rain and I was able to re-check the valve clearance, paying special attention to rotate the cam marks to point at each other, I gathered the following measurements:

Left Intake:
Still < .04mm (maybe .03 because it feels like it almost might go.)

Right Intake:
Closer to .55 / .56 mm Bucket still will not turn easily.

Right Exhaust:
Right at .08mm

With the cam marks pointing away from one another:
Left Exhaust:
Right at .18mm

So definitely much different than before. Once the rain moves out, I am going to re-do this check and try to get the exact measurements. I was simply rushed to beat the rain and didn't write it down. I also need to get some smaller thickness feelers and a caliper that will give me .001 mm to be more precise.

I am still wondering at this point if I just need to remove the camshaft on the intake and try to remove the bucket to see if I can determine what is making it tight.

Again, any suggestions are appreciated.

CB

[jp]

Pull the cams and remove the buckets. You can swap buckets around between cylinders to try and find a combination where they will all spin freely. If the bucket is sticking, there is a chance that you will bend a valve if it sticks at the wrong time. Personally, I think you're getting that huge clearance on the valve because it is sticking, and not giving you a true reading.

[bill14224]

I agree with JP.  The clearance on the sticky bucket's valve is so big it's very unlikely to be accurate.

[cboling]

Alright, I raced against the rain again and pulled the head off. I pulled the left intake bucket out no problems but the right intake bucket is stuuuuuuck! so no that I have the head off again, what it going to be my best bet for getting this bucket out? What else should I look for when it comes out as far as the valve is concerned? Can I tell anything about the valve with it in the head?

I will be reading the Clymers more later but any specific tips are appreciated.

Thanks,
CB

[gsJack]

I had a tight bucket on an exhaust valve that resulted in a broken valve.  Before it broke, I could not turn that bucket by putting a screwdriver in the shim notch and hitting it hard with a light hammer.  When I pulled the head I drove the bucket out using a long pin punch and heavy hammer from the inside driving the remaining piece of valve stem up against the bucket.  It drove out hard all the way, was very tight.  Yet before the valve broke the head would heat quickly and the bucket would free up and the engine would run smoothly in a minute or less.  No problem for the rest of the day, that was why I let it go for a while hoping it would wear in and free up.  Must have come from the factory with a tight bucket too big for the bore in the head.  Required a different bucket to fix problem.

Some check valve seal by pouring some water in the port with the valves head downwards to see if it leaks past the valve.  Good valve seal should hold water back.

In the end I was lucky the valve broke without further damage to the engine so I could drive the bucket out from the inside.  If I had to remove your tight bucket I think I'd try heating it in the oven to 300-400F and see if it won't just pull out easy then.

Since aluminum expands faster than steel when heated the bucket loosens as the head is heated same as valve clearances increase as the engine warms.

[cboling]

"If I had to remove your tight bucket I think I'd try heating it in the oven to 300-400F and see if it won't just pull out easy then."

Thanks GSJack. I had read your post (at least some of it) I might have missed what you did to remove the bucket. i will try the oven heating this evening to see if that makes things easy.

[cboling]

DING! DING! DING! DING! DING!

GSJack is the winner! Easy enough a caveman can do it.

I placed the head in the oven and let it bake until golden brown and viola! Out slides all of the buckets with ease. And now for some tasty pics.





Now for more questions:
I don't think there are any big shards of that bucket down in the valve seats however, if I want to clean them out with some solvent, what would be the best to use? I was thinking a cleaner sprayed through the top of each valve and drained the same way.

EDIT: I waited for the head to cool down enough that I could touch it and tried to fit the left intake bucket in each of the valves. It seems that it only fits smoothly back in the left intake. All of the other valves seem a bit tight. I also took a look at the left exhaust bucket and saw a dark spot on the bucket which looks like it is rubbing and getting hot. Should I just consider pricing a valve job on this head?

Thanks,
CB

[gsJack]

No way a piece of that broken bucket could reach the valve seat.  I can't see clearly if there are 2 valve keepers on that right intake valve or not.  Looks like only one in the pic and that could chicken the springs and sideload the bucket causing the sticking problem.  If the pieces of that bucket skirt are anywhere they would be down there in the head c'bore somewhere with the springs.  I suspect someone installed it broken that way, no way it should break in operation.

Best way to make sure there are no bent valves and that there is good valve seal is to lap the valves if you have or can fashion a spring compressor to remove the valves and lap them in.  I lapped mine in when I repaired my engine and have put another 50k trouble free miles on it since and it still runs like new at 71k total miles.

[The Buddha]

Woweee ... that was insane ... you were lucky I'd say ... the broken piece has to be found ... though it was broken before assembly possibly.
You find that bucket piece though - you're home free ... Yea, get a new bucket.
Cool.
Buddha.

[Trwhouse]

I have a Honda valve spring compressor that you can borrow if you need one, if you pay shipping to you and back.
It's an old OEM compressor, like a big screw-in C-clamp with a fitting to go over the spring keeper.
I can measure it's width to be sure it fits your GS500 head if you tell me the measurement.
Or I'm sure you can find something workable in your neck of the woods.
Best wishes,
Trwhouse

[cboling]

Thanks all. Trwhouse: I may take you up on that offer. I'll need to get the measurements this evening. Are the valve spring compressor tools specific to the vehicle or is there a semi standard tool at somewhere like harbor freight / sears / autozone?

Gsjack/ bhudda: if the valves are bent due to some other known problem, would it be obvious visually?

[gsJack]

Could be hard to see, depends on how badly they are bent.  Try the water in the port method I suggested above, turn port up and fill with water and see if it leaks past the valve if you want to check it before you pull the valves.  Lapping the valves will prove whether they are bent or not and improve the seal at the same time if they aren't bent.

It still looks to me like there is only one keeper in that right valve assembly which could chicken the spring and cause binding.

[The Buddha]

Yes water in the port - rather the head method if they are apart, and on a bike that was still assembled, I had lopee find it by putting a bright small flashlight in the spark plug hole and looking for light in the exhuast port.
If its apart, water in port is better ... or heck do gasoline if you prefer that, and make sure you dont have a ton of caked up carbon there to clog it up ...
Yea spark plug gotta go back in.
Cool.
Buddha.

[cboling]

Update: I gathered some tools to lap the valves (if I get that far.) I did the water test by pouring the water in each port (Intake and Exhaust) water only leaked out of the right intake (bad bucket) valve. Stay tuned as I go forward.   

[cboling]

Okay, here is what seems to be the issue. I went to Sears and got an automotive Valve Spring Compressor (it is large and has an adjustable pin which pushes against the valve head, then a fork that fits over the valve retainer ring. When you squeeze, it pushes against the retainer and allows you to remove the keepers.) Problem with this tool is that it doesn't really fit the retainer ring so I placed a socket underneath the fork. I inserted a magnet to remove the keepers inside the socket. (Which is not going to work for putting them  back in.)

After removing the keepers and the springs, I took a picture down inside the bore of the head. Nothing too out of the ordinary however, I did find some aluminum bits and slivers. (See picture.) Nothing major and they were around the springs which I believe would not cause a problem.



I removed the valve which was a bit tight to come back through the guide. I made sure there were no visible burrs but not sure if that would cause any problems.

Anyway, I cleaned everything out decently and put some lapping compound on the edge of the valve and replaced it in the head. (Still a bit tight going the last few mm.) I pushed the lapper tool suction cup on and carefully began to spin the valve. Not bad so fa.......crap! It is tight!! So I removed the valve again and cleaned everything off.

I laid valve stem on the edge of my desk / table (Really flat) and rolling it along the edge of the table, you can visibly see the valve head wobble. (Gosh dang it!)

So with all of that said, What does YOUR experience tell me?
Option 1. New valve, guide / seal, bucket for just the one cylinder?
Option 2, All new valves, guide seals, buckets?
Option 3. Take it to a machine shop and let them do it all?

Having asked those questions, I am really happy and thankful for all of the encouragement to tackle this myself. I would like to try to repair it all the way myself but if in the long run, i end up having to get it fixed professionally, I don't want to do throw money at unnecessary parts.

I may try to pull out the left exhaust (the other one giving me some issues with clearance and see if that one goes smoother in the lapping process. (Wish me luck and joy!)