valve shims

[XSokieSPECIAL]

no problem bro! glad to help.

By the way, those shims come in 0.05 mm increments, not those odd thicknesses you were coming up with, so you need to install the shim to make your clearances closest to the minimum of the spec as you can.

COOL?

Once again, check those cam bearing caps before you go any further.
( sorry, I'm stuck on that since I had that problem with mine )

[Geezer]

no problem bro! glad to help.

By the way, those shims come in 0.05 mm increments, not those odd thicknesses you were coming up with, so you need to install the shim to make your clearances closest to the minimum of the spec as you can.

The odd sized shims came in the bikes from the factory but are unavailable from the parts department... Most of the time the standard sizes are close enough. Sometimes I used to measure a bunch of shims to find one that was a bit thinner than the rest of that size when one was too loose and the next one was too tight...

Geezer

[SFSPECBIKER79]

no problem bro! glad to help.

By the way, those shims come in 0.05 mm increments, not those odd thicknesses you were coming up with, so you need to install the shim to make your clearances closest to the minimum of the spec as you can.

COOL?

Once again, check those cam bearing caps before you go any further.
( sorry, I'm stuck on that since I had that problem with mine )

right on i have never done this before, i guess the time to learn is now, i have 3 xses now and none of them have never had a major tune up, they have close to 30 thou. on them now. i want to see what kind of juice i got. if you know what i mean. they are running ok. i just want learn how to tweak them. i'll tork the cam bearings to and recheck the clearences. that sound like good logic to me, thanks for the tip i have nver thought of that one eventhough i have worked on engines for most of my time.

[TopCatGr58]

no problem bro! glad to help.

By the way, those shims come in 0.05 mm increments, not those odd thicknesses you were coming up with, so you need to install the shim to make your clearances closest to the minimum of the spec as you can.

COOL?

Once again, check those cam bearing caps before you go any further.
( sorry, I'm stuck on that since I had that problem with mine )

Hey Greg,

Since the clearances tend to shrink/reduce with engine wear, IMHO it's better to err on the wider/larger clearance range...yes a little noisier perhaps, but you won't have to do the adjustment anywhere as soon as if you tried to set it to the smallest clearances, and less chance of burning valves!

I guess retyping/editting Rowdy's post, and then replying to it wasn't seen/read?? The values I provided were from his statement of an 80G. They would possibly need to be adjusted for the Intake for the 79 engine.

Tony, thanks, I didn't know that they/Yamaha had/used odd sized shims, their official spec/parts sheets also state only the 0.05 increments!?
T.C.

[XSokieSPECIAL]

I'm been an auto tech for over 30 years and I'd never run into it before either, never even thought of it. Discovered it by accident the 3rd time I was in there. Saved my engine. Probably just a freek thing but now I'll always check.

[XSokieSPECIAL]

Sorry TC , our posts are flying fast and getting out of order, don't mean to step on any toes.

I'm new to this engine but learning fast about it's idiosycracies. Trial by fire you might say.

[DGXSER]

Hey Rowdy,

Soo despite having a G model bike you have an F model engine (or SF). Which means you need the larger intake clearances of .16-.20mm, and the exhaust should be .21-.25mm. I'm going to repeat the work TC did for you with the new clearances (at least to my math skill abilities) so see the GREEN text in the quote area as my info to you. What you got is;

On clylinder 1 the clearance is
; intake 0.16mm the shim i have installed is 2.56mm I would switch out to a 260 shim.

# 1 exhaust clearance is: 0.20mm the shim installed is 2.88mm. I would install a 290 shim

clylinder# 2
intake setting is:0.20mm shim installed is: 2.50mm Leave it as is.
exhaust setting is 0.25mm. shim installed is 2.80 Leave it as is

clylinder#3
intake setting is: 0.23mm shim installed 2.75mm I would install a 280 shim.
exhaust setting is 0.28mm shim installed is 2.75mm. need a 280 Correct

clylinder#4
intake setting is 0.18mm shim installed is 2.70mm, Leave it as is.
exhaust setting is: 0.20mm, shim installed is 2.86 I would install a 280 shim, yes it puts your clearances 1mm over spec.

As to the tool or not the tool, well, for 5 out of 8 I would probably go with the cam loosening method. TRBig did a GREAT writeup and very detailed on how to do this recently. If it had pics it could be a tech tip I think. It really is not that tough to loosen the cams up. I adjusted my valves not to long ago and used the tool to do mine. That was before the write up mentioned, after reading that for more than two or three shims, I would do the cam method myself. Then you WILL recheck the torque on the nuts!

Anyway you go about it, you need to get a few shims. Good luck and have fun.

I saw it TC and wondered how the rest missed it.

Hey Greg, I think it is always good to check the torque while your in there, and I would also say that your is the first I have heard of that happening since I have been here at XS11. I do not think it is a common issue with this engine, as much as you had a PO that dorked with the nuts and did not tighten them back correctly. Again, never hurts to check something while your there though.

[SFSPECBIKER79]

reshims

thanks, im glad i checked the num. on engine on the bike. i for got the motor had been changed but didnt no that a earlier model had been used, all i have to do is get the shims and install them. thanks to the experience you fellows have makes it a lot easeier for the less experienced ones like myself. thanks i'll post back when i get the thing running again. this is the same bike that the ballast resister went out on, and topcat helped me resolve that. i havent received the replacement yet but, it should be here by the time i get the valves set. then i can start it up and hope it is running smooth like it should, done replaced carbs,plugs. trying to cure the popping, i think that the valves may be part of the problem after checking the clearences, thanks

[XSokieSPECIAL]

DG,
Like I said, I'm new to this engine and just learning.

Yea, the PO probably tried to adjust the valves using the loosening method and didn't retorque properly.

Just trying to share my experience, limited as it may be, with someone who admittedly has less. With the noisy valves I had and as many times I attempted to solve the problem with adjustment, before the real problem became apparent, I had the specs memorized and could pull the vave cover in a matter of minutes. (LOL)

TC,
Not arguing with you, but in my experience the top end of the valve train ( cams, lifters, and in push rod engines, rockers, and push rods wore more quickly than valve faces and seats. Is this engine different in that respect?


Greg

[Crazcnuk]

You can get even smaller increments by using Taurus SHO shims. They come in inbetween our sizes as well.

[DGXSER]

Greg, I am with you that it is certainly somethign worht checking while your in there, I just do not think I will e pulling my valve cover to check the torqueo n those nuts specifically is all.

In this engine the valves stems sit directly in the buckets which have the shims in them. What I understand is that the valves will over time seat deeper into the head ever so slightly causing the gap between the valve shims and the cam to decrease. The other issue that cand evelop is burning the valve or carbon deposits that will not let the valve seat properly opening the gap. That is my best take on what I have read here.

[TopCatGr58]

Hey Greg,

Sorry, didn't mean to get pissy, it was late last night, I was a bit tired, etc.!

Yeah, many other types of engines tend to get larger gaps, but these machines like to decrease their gaps with age as DG stated. But once an engine is well seasoned, and a valve clearance adjustment is done, they can often last for 10's of k miles!! Such is the design/ durability of the wonderful XS11 engine! And so that's why we mentioned the use of the wider end of the clearance spec due to the tendency of the gap to decrease with wear.

And the concern of IF they wear, and the clearances are already set very close, then they could start not closing all the way, and get burned, then you have a valve job to do, much more of a PITA than the shim adjustment!
T.C.

[XSokieSPECIAL]

Hey TC,

That's what a discussion is all about isn't it? No worries. It was no thing.

Besides, I was pretty tired too and it was my day off so I had, let's say, a couple of brews.

I'm trying to learn as much as I can about this rocket ship and I certainly appreciate picking at the brain of someone as knowlegable as you. I'm kinda hard headed at times and I've been known to occasionally be a bit annoying in that respect.

You'll come to know and love me. LOL

Greg