valve stem seal replacement question (and a few pertaining to this)

[ERM83]

ok, so I have my cams out, got the shims and sleeves out, and am at a point where I can get the keepers out. this would be where I find out whether it's the valve stem seals, or the piston rings. there IS a bunch of gummed up oil on the #1 and 2 exhaust headers. seems like it would be a stem seal problem? i'm just not sure, because oil flying out of the crankcase vent sounds like rings...

the manual says to NOT crank the engine after the cams are out, but some of you said that you can, just be VERY careful. that being said, can I do the rope trick to keep the valves from falling into the cylinder? I did some research on here, but wanted to see if it was possible to do that without screwing anything up.

that being said, should I (while I'm in there) just say "hell with it", and take the head off, and check the rings? I don't want to go messing around in there if it indeed IS the stem seals. plus, I don't have a ring tool.

one last thing...my chain came off the crank sprocket. it didn't fall into the engine...I have it tied up to prevent that. any tips / precautions are appreciated!

Thanks for all the help, everyone...I'M SO CLOSE TO GETTING THIS THING RIPPIN'.....

[kboehringer]

A few pointers

ERM,

Here's a few answers/suggestions.

You can't do any damage turning the motor over now that the cams are out. All the valve springs SHOULD have retracted their valves so turning the motor over will not result in the valves smacking the pistons. This ASSUMES all the valves retracted properly. Since your cam chain has already been displaced from the crank you can't do anything bad.

You can NOT check the rings by merely pulling the head. You will also need to pull the cylinders to check/inspect those. A ring change does not need any special tools but I find a ring EXPANDER is valuable. It can be done without.

I have changed valve seals in CARS using the "Rope Trick". Having never done it with an XS11 motor I can only say I don't see that being very easy. It will certainly be MORE difficult than just pulling the head. The XS11's valve springs, and valve are recessed into the head (unlike most car motors) it will be a difficult proposition using the rope rick and being able to compress and re-compress the springs. IN MY OPINION, just pull the head. I made a nice valve spring compressor from a HarborFreight C-Clamp and an old socket that works GREAT for about $10!

There are complete aftermarket gasket sets available online for about $75 that include the valve seals and the head gasket. I've done three in the last year and the gasket kits I purchased were great!

Rings are not available from Yamaha. Again, these can be had from a seller in Japan for $50. I have purchased a couple of these and am very happy with them. Removing and installing the cylinders can be a major PITA.

You can relatively easily get that chain back on the crank. I've had it slip off too. A coat hanger and a little giggling and it can be done in a couple minutes.

Hope that helps.... if I think of anything else important I will add it...

KURT

[TopCatGr58]

Hey there,

Okay, IF the cams are OUT, then there are NO valves being pushed down into the cylinders, so nothing can be hit by the pistons coming up! But you'll need to take the spark plugs out if you haven't already so you can rotate the engine without having a vacuum pump affect as 2 pistons move downward away from the head, as well as a compressor affect by the other 2 pistons moving UP toward the head.

Now, to get the valve seals off, you will have to remove the valve keepers by depressing/compressing the valve springs. The valves will want to move downward toward the piston as you compress the springs. This is why a valve spring compression tool looks like a large "C" clamp so it can keep the valve in place while compressing the spring far enough to gain access to the keepers to then remove them and then release the compressor to slide the spring off to finally gain access to the oil seal.

SO...without taking the head off, you'll have to either hook up a fancy air compressor to create positive air pressure in the cylinder to hold the valve in place while you compress the springs to get the keepers out. This will require a fancy valve spring compressing rig that you will have to bolt/secure to the top of the head.

Other techniques I have heard of is shoving rag into the cylinder thru the spark plug hole and then rotate the engine up to compress the rag against the valves while then compressing the springs.

SO...unless you have the special bolt on type spring compressor, then you'll probably need to take the head off to be able to perform the compression/keeper removal process!

http://www.xs11.com/forum/showthread.php?t=148

http://www.xs11.com/forum/showthread.php?t=35575

Here's an old thread that shows a custom made bolt on valve spring compressor tool/rig. In it I also talk about a slight modification to Tod's/Trbigs C-clamp type tool.

http://www.xs11.com/forum/showthread.php?t=35575

T.C.

[kboehringer]

Questions?

ERM,

After typing the previous.... I thought of a couple questions that might make it easier to give you some instructions:
1.) What was the compression before you started this process?
2.) Did you have properly adjusted valves when the compression was tested?
3.) How many miles are on this motor?

IF the bike had good compression and low miles, there is not (depending on your budget and how fast to want to be on the road) much reason to go after the rings. Although, your oil coming from the vent COULD BE an indicator of compression/power blowing by the rings.

The "Rag Trick mentioned by TC is the same as the "Rope Trick". As mentioned by TC, keeping everything together and pulling and installing keepers etc. on this motor will be a TON more difficult than the Rope Trick on a Chevy 350. IF I were to try that, I would prefer the rope. It's less likely to leave pieces in the cylinder and easier to install and pull back out.

Another advantage to pulling the head is you will have the ability to de-carbonize the head and the piston crowns.

KURT

[kboehringer]

Spring Compression Tool

Here's another homemade spring compression tool that does NOT require a sacrificial shim bucket which you may not have? You will have to sacrifice an old socket. It also uses the supplied clamp flexible pad to contact the valve face.

[TopCatGr58]

ERM,

Another advantage to pulling the head is you will have the ability to de-carbonize the head and the piston crowns.

KURT

Not to mention being able to LAP the valves/seats to ensure you have a great seal and freshened up valves/seats!

Kurt, I had forgotten about stuffing the rope into the cylinder, was thinking "How would you tie a piece of rope onto the end of the valve to keep it from dropping?"

T.C.

[ERM83]

Thanks for the help, everyone!

T.C.! the ro pe trick involves getting the cylinder all the way down on the compression stroke, stick about 6ft of rope down the spark plug hole, THEN hand-cranking the engine gently until it stops, thus, compressing the rope so that the valves won't drop! I have a valve keeper tool, but after much thought and all of your advice (everyone!), i'm going to just remove the head. also, I think it was kurt who said this...I knew I had to go a step further than what I was talking about for the rings, and I should've been more clear. apologies! i'll take some pictures tonight for sure, and put them up on here. I can't reiterate how much I appreciate your all's advice...I LOVE this bike, and i'm going to make it a true one-of-a-kind. will report back soon!

Eric

[ERM83]

I am going to pull the head...already used liquid wrench, and the piston heads look a bit...used, haha. man, my shims, cam, and crank / timing parts under the covers on both sides look BRAND NEW. I think this came from two PO's ago that didn't have anymore time to give this thing some love. cosmetically, it's not beautiful, but inside (minus the pistons and seals) looks GREAT. sooooooo PSYCHED! going to the garage now!!!

[ERM83]

Ahhhh, sorry T.C. ...I meant getting the piston down on the intake stroke, THEN putting rope in, THEN compressing the rope. either way, i'm REALLY glad I took the head off. pics, go-through, and (for sure) questions to follow! everything on 1 and 2 looks pretty rough...logged up everywhere with sludge. i'm beat, or i'd post pictures now. first thing tomorrow, i'll post them.