Fun with lifter

[RichV]

I know I'm opening myself up for major ridicule but I ran into a problem with the lifters.

Of course this would happen when I'm just about finished.

I had a difficult time reinserting the lifters just before placing the cams in the head. They were not sliding in like they should. The intake lifter for #1 was real hard to get in. Well after getting the cams installed I notice that it was not returning up to where it should. In other words, the valve is stuck open. It does push down and come back, just not all the way.

To make maters worse, all of the clearances are out of spec. I lapped the valves when I replaced the valve seals so that could be part of the cause. The valve now look good and they seal fine. So for clearances I have:

Cyl 1 - E=.15 I=.8+ (stuck one)
Cyl 2 - E=.18 I=.04
Cyl 3 - E=.18 I=.08
Cyl 4 - E=.13 I=.04

All measurements are in metric (mm). The ranges should be E-.21-.24mm and I=.16-.2mm

So my questions are:

1. How can I "unstick" this lifter.
2. Is there an easier way to change the clearances other than replace the shims. I'm so far out, I may not find the right thinner shims.

All I know to do is to remove the cams and try to pull the stuck one out.

Thanks again for all the help. I guess I won't be starting it up this week.

[SFerinTEXAS]

Probably a silly thing to ask but are you sure there is a shim on that bucket?

[RichV]

Yes, all of them have shims. The sticking lifter is not returning back to the top position.

I'm thinking that something must be stuck between the side of the lifter and the wall. Anyway, it the spring isn't pushing it all the way up it's going to be a bear to remove.

[SFerinTEXAS]

Could be the spring is not set centered under the keeper or Lord forbid somehow the valve got a tiny bit bent.
If you took the cam out I wonder if you could get a tiny flat blade screwdriver on the oppiste side of where its jambed and gently tap it around the tunnel and force it to center? Just throwing things out there.

[TailspinTommy]

Shims

Hi Rich,

Sorry I can't help you with the stuck lifter. Did the lifters go back into the same valves they came out of? I was wondering if that would make a difference?

While you’re waiting for someone who can help with that, I thought I’d take a stab at the shimming…

I think shimming is as easy as it gets to adjust the valves and the only practical way I can think of to adjust them. From what work you've done so far, it should be a piece of cake.

Knowing the shims that were in those lifters when you took those measurements would help decide what new shims you need. For example, #4 Exhaust is currently .13mm. The new shim would have to be between .08-.11 mm thinner to put that valve in spec. So if the shim that gave you the .13mm measurement on #4 Ex was a "270" (2.70mm thick), you would need a "260" shim to put that valve in spec. In this example, a "260" shim would give you a (calculated) .23mm clearance. I believe my calculations in this example are correct.

Except for the sticky lifter, which won't be fixed by a shim, I don't think your clearances are hopelessly out of bounds. Yamaha 29mm (diameter) shims range from "200" to "320" so "260" shims are in the middle of the shim spectrum of sizes (I've only seen a few of those sizes available at Partzilla). If you're not near the 200 size on your current shims, I would think there should be shims available somewhere to put your valves within spec. You may be able to use some of the shims you have on your other valves. Also, I've seen links in other threads of this forum to places that sell aftermarket shims for reasonable prices. I've heard of others being able to trade in their old shims for the ones they need at local shops for a small fee.

TT

[PMKXS11]

Is it possible it may be a little out of round?

[Radioguylogs]

I wonder if you could get a small screwdriver in the slot on the perimeter of the 'lifter' and try rotating it to see if the spring will push it up once it's kinetic friction instead of static friction. Also it may find a position that better matches for out-of-round tolerances.

If you haven't pulled the cam yet, you be able to try this idea using the shim tool.

This ebay listing has picture to help visualize the slot:
http://www.ebay.com/itm/NOS-Yamaha-O...c41b26&vxp=mtr

Good luck. These things always seem hopeless on the day they happen, but sometimes an easy solution comes after some thought and investigation.

[trbig]

By "Lifters" I'm assuming you're talking about the buckets. These buckets are very picky about not going back in unless absolutely straight with the recess they go in. If you tried to force them in any way, you may have damaged the walls they slide against. These buckets are extremely hard steel, so doubt you bent them unless you drove them in with a hammer. If the buckets are straight and you had them lubed with some kind of oil or assembly lube, when they are straight and inline, they'll slide right home.

So, I see one of two options, neither one good, but I'd get a 2nd opinion on this as well. As stated, either the valve is bent somehow, or the aluminum wall the bucket slides in was damaged. I'm not even sure of how you'll get the bucket out. Those springs are pretty heavy duty, so if they aren't pushing it back up, I doubt the usual trick of trying to pull it up with a magnet will help. Tapping on the valve to push it up.... if the valve wasn't bent, it likely will be after that. I like Radioguylogs' idea of trying top spin the bucket around, hopefully letting the springs do their job.

Sorry, nothing but bad news from me...

[RichV]

Thanks everyone.

The buckets went back into the original slots.

The valves are not bent. At least they weren't when I put them back in. They operated smooth and true.

Something is catching it near the top of it's travel.

I use assembly oil on all parts.

The spring out of whack sounds like a good thing to check. It could be slightly off and pushing the bucket to the side. In any case, I need to remove the cams and check it out. At the same time, I'll check out the shim sizes.

Shore hope the head is okay. I don't know where to get another one and the other one I have has problems.

I have the flu so this may take a couple of days but I will report back the results.

[RichV]

Okay, I pulled the head off and removed all of the buckets. The #1 input was very difficult to get out. I had to heat the head with a torch.

So four when in and out no sweat with a magnet
Two came out slowly with some binding but the magnet worked

One came out in stages a little bit at a time with the magnet.

And one (#4I) didn't come out until I heated the head and then I had to grab the lip with plyers.

So the only thing I can think of is to pull the valves again and inspect. maybe I got a spring upside down. I am lexdysic after all.

So are the springs narrower on one end than the other? What if I did get one upside down?

By the way the shims are Y280-Y290.

[RichV]

Okay, here's what I can do.

I'm using shims from two bikes to make the 8 I need. Here are the data listing from 1 to 4. First number is In, second is Out. Cylinder #1 In is not measurable right now.

Shims
2.75
2.85
2.8
2.85
2.8
2.8
2.85
2.9

Gap
Unk
.15
.04
.18
.08
.18
.04
.13

I Need
Tbd
2.75
2.65
2.8
2.7
2.75
2.7
2.8

Based on what I have with this bike I need a 2.7mm and what ever 1I needs.

I can guess that 1I will be 2.6mm or 2.65mm based on the other gaps.

I don't expect anyone to check my math. Just if I'm going in the right direction.

[TailspinTommy]

I got what you got

Hi Rich,

Using your info on old shims and clearances, I came up with the same new shims that you did.

TT

[RichV]

Thanks. Battling some flu here so my math could be off.

Anyway, I'm going to fix the valve "bucket" on #1 input. Check the clearance and then order the shims.

Has anyone ever frozen the buckets before putting them in? My garage is really cold right now (40Fdegrees) and I was thinking I could take the head inside so it's warmer and freeze the buckets to provide a better temp differential.

I'm also going to check the springs to make sure their installed correctly.

Life is a learning experience.

[trbig]

Yes, there is a proper way the springs are supposed to be installed. They're "Progressive" in style, meaning the end with the tighter coil should go to the bottom.. but it's hard to tell. The direction of the coils are opposite between the bigger and smaller springs.

Heat shouldn't matter on those buckets. These bikes are good in the dead of winter to the worst summers, so it seems to me that if the valves are good, something is out of round on the bucket or there's some kind of imperfection holding it up. Glad you got it out to be able to inspect better though.

Try swapping one of the other buckets into that hole and that one into another slot and see.. That'll tell you if it's the bucket or the hole it goes in. Though I like to keep each bucket to it's respectable hole also, they should all be the same and interchangeable.

[RichV]

I moved the head inside and cleaned up the buckets better. All eight are now installed and not binding. They all spin and come out with a magnet.

I was able to get all but two shims: Y265 and Y270. I'm currently looking for a source.