Tight Exhaust bucket, Broken Valve?

[McD]

BACK STORY: 02 gs with 14k miles.  I've Read, searched, and wrenched almost as much as i've ridden.

While checking my valve shims i noticed my Left exhaust bucket was tight. As in, i could remove the shim tool without the bucket popping back into place. It popped back fine while in motion, (spinning the engine) and the bike ran fine before, so i figured it might be alright. The shim was VERY out of spec though.

After replacing the shim with one a few sizes up a loud BANG and pop, and then nada. Finger-to-spark-plug-hole reveals no compression on that side. 

Looking back now i reckon the sticking bucket might have given a false shim reading, and a few sizes up was just enough to snap a valve.
GSjack has been in every broken valve and/or tight bucket i've searched for. Maybe it's an 02 thing?

QUESTION TIME!!

Any way of confirming this before taking half the ENTIRE bike apart? Plus i don't want to start ordering parts on just guesses.

Removing the head (as recommended for other broken valves searched) will be the biggest project i've tackled. Doable with basic tools/knowledge? In an apartment complex's parking lot?

If i remove the head Today, but don't have the parts to reassemble today, can i just trash bag and duct tape all open surfaces?

What else should i know before diving in? Just looking to ride more, and read less.

[Weston]

Take off your exhaust. Its easy, its like 5 bolts total. Look inside the port... there you will see your valve, if its completely broke you will be able to tell. I just took off my head and am working on putting it together, you will want a socket set, a repair manual, a torque wrench, hex set, maybe a few other basic tools. Its nice to have a repair manual though, i wouldnt do it without one.

[McD]

Bumptastic for the night crew. I'm bagging it come tommorow. Just looking for a little more insight.

[Weston]

Also, I would reccomend getting a garage or somthing. You might not be able to finish it in one day if you discover that there is another part that needs replacing. And what if it rained... that would not be good if your motor was apart.

[gsJack]

I was fortunate to still have my old 97 GS when my 02 exhaust valve broke so I took about 3 weeks time to fix my 02 and rode the 97 while it was down.  A forum member (davipu) sent me an exhaust valve and a set of buckets and I ordered the gaskets after I tore it down.  Out of 4 slightly used buckets from an engine that had been parted out only one would fit that head bore without sticking.  There was no selection of bucket sizes when ordering a new one so I assumed the problem was caused by a slightly undersize bore in the head.  Or perhaps they select fit at the factory. 

After the valve broke I could not crank the engine with the starter as it was locked up.  I could only turn it a wee bit back and forth with a wrench on the end of the crank.  I could see the broken valve thru the sparkplug hole.  If you can crank it to check compression you probably just bent a valve.

No reason you can't fix it in your appartment parking lot unless they have rules about working on vehicles there.  I fixed mine in a garage but carried the head over to the apartment kitchen to work on it.  Keep all your loose parts and tools in the car trunk and cover the engine with a plastic sheet well tied down while your waiting for parts.  It wouldn't be a disaster if it got rained on while sitting there apart.  If you get water in the crankcase just change the oil before you restart it when your done fixing it. 

[McD]

Well, the stuck bucket is just that, STUCK. the valve was stuck slightly open. Is slightly enough to cause contact?

I'm seriously considering tossing my cylinder head in the oven to loosen the bucket enough to remove it. Or bringing out the big hammer. Any better ideas?

Also The buckets from my NON sticking valves fell right out, how the EFF do i get those back in? Will i have to remove the entire valve?

Plus I'm thinking (with GSjacks experience) that there might be a good chance a new bucket won't even fit eh? Whats the stupidity level of whipping out some FINE FINE sandpaper and WD40 and round that sonova B up?

I'll prolly have more questions as a go, but thanks for all the help so far!

[gsJack]

The buckets that fell right out should slide right back in.  Put a little oil on them and slide them in carefully.  Kinda like putting brake caliper pistons back in, you have to go easy and get them started straight.  If they get cocked they will lock up and you'll have to tap the outer end sideways a bit to get it loose again.  No need to remove the valves that aren't damaged.

Heating the head in the oven isn't a bad idea.  If you get it up to 300F or so you should be able to grab the bucket with pliers with the shim out and lift it out.  My sticky bucket really was tight but with the head of the valve broken off I took a long pin punch and drove it right back out with a hammer from the inside out.  Pic of my broken valve:



My stuck/broken exhaust valve hit the intake valve and the piston, I could see it from the markings.  The intake valve had a small nick in the outer edge so I removed it and lapped in both valves on that cylinder, the old intake and the new exhaust, to make sure they were straight and sealing.

I was thinking the same about a new bucket possibly being too tight but I don't know.  There is no choice in sizes but they may make replacement buckets a little smaller so they'll fit any hole size tolerance wise.  Maybe someone here knows?

If you have a lathe available you could just chuck up that tight bucket and work it down all around with some fine emery cloth.  Would be more even than trying to do it by hand without a lathe to spin it but it might be doable by hand.  You'll need a valve compresser tool or rig something up to get the keepers in and out to remove and replace valves.

I discovered my sticking valve at about 10k miles when I first checked the valves, bought the bike used.  I let it go since it wasn't a problem hoping the bucket would wear a bit in the head and loosen up in time.  Another check at 21k miles and it was still sticking and when I finished up and tried to start it the valve stuck further open and crashed.  It was a cold day around 30F and the bucket was tighter.  Normally for it's first 21k miles or so the engine would start a bit rough and then smooth out in 30-60 seconds as the head heated up and the bucket loosened.  No problem after that until it was shut down and cooled off again.

[lopee]

When i replaced my head, buddha and I used a real strong magnet on the buckets, one was real sticky, so we lubbed it good and gave her some persuasion prying her with a screwdriver. Also we  had the same problem getting my old buckets back in the newly machined head. Just mixed and matched till they felt right. Suzuki must fit these per bucket cause tey all seamed like a different size, but the valves had just been worked and reinstalled, so there might have been some variation in how they were reassembled.

[The Buddha]

Yep lopee is right, Those bores were somehow bored to fit a bucket they fell like that.
Cool.
Buddha.