Valve Tappet too Small 1.6-1.8mm?

[BassCliff]

(Measurements are between the two numbers smaller number fits, bigger number does not)
Exhaust
#1 = 2.50mm Shim, Gap .15-.18
#2 = 2.60mm Shim, Gap .08-.10 (.09)
#3 = 2.60mm Shim, Gap .13-.15 (.14)
#4 = 2.55mm Shim, Gap .08-.10 (.09)

Intake
#1 = 2.00mm Shim, Gap .10-.13
#2 = 2.70mm Shim, Gap .06-.08 (.07)
#3 = 2.90mm Shim, Gap .06-.08 (.07)
#4 = 2.70mm Shim, Gap .04-.05

Hi Mr. Roland,

With the shape your cam journals/caps are in, I guess I would be satisfied with your results. The one exception would be the #3 exhaust, that's a little looser than I would run. If you stuck a 2.65mm shim in there, theoretically it would bring the clearance to .09mm.

Like Mr. posplayer said, perhaps you've bought yourself some riding time but I wouldn't count on it as a permanent solution. I can't guess how long the upper end of your motor will last like that. But these motors are very durable and can take a lot of abuse.

You've done good work. I hope your efforts pay off with a very long riding season.


Thank you for your indulgence,

BassCliff

 

[Roland]

Persistance will pay off

Persistance will pay off

O.K. it seems pretty unanimous that I have gotten it this close so I should go ahead and at least get the #1 & #3 Exhaust a bit closer

I don't think my local shops have what I need but I will check. If I am going back to the store to pick up a 2.55x for #1 & a 2.65x for #3 exhaust I might as well buy another one for #1 intake and have it ground to 2.05 which should bring it to .05-.08.

I did check the compression and guess I should have reported on that a long time back I am getting the following:
#1 = 136, #2=117, #3=115, #4=120

 

[Steve]

While doing my search for my missing shim sizes, I came across a diagram to help track the valve adjustments.

Our member "Steve" has a good Excel program for that need.

True enough.

If you are interested, send me an e-mail (address is in my profile) with a request and I will send you a copy. I like the diagram, too. Might help with the visual part, then transfer the numbers to my spreadsheet.

By the way, good luck trying to find X shims at the shop. If they have to order them, they can't be ordered, as far as I know. Your best bet is to see if the shop will exchange shims with you for a small fee. When trying to consider whether a fe is reasnable, keep in mind that new shims are available from Z1 for $5.28, and will allow you to build a small inventory for later adjustments.

.

 

[Guest]

I thought it was unanimous that the head was junk.
Good luck

 

[Dan Ruddock]

Please let know when it fails so we can say "told you so" Dan

 

[BassCliff]

O.K. it seems pretty unanimous that I have gotten it this close so I should go ahead and at least get the #1 & #3 Exhaust a bit closer

Oops, I didn't notice that #1 exhaust was so loose. Yes, tighten that up with a bigger shim (2.55 or 2.60) if you can. I agree with Mr. Steve, the 'x' sizes are hard to find.

But keep your eye out for a new engine, or at least a new head. Keep us informed.


Thank you for your indulgence,

BassCliff

 

[Roland]

Respect the Classics

Respect the Classics

Chef you are so negative. How about "O.K. but be extremely cautious for the next 500+miles and keep in mind that your summer may be cut short with head issues."

Dan you are negative to the MAX!! WOW!! That was not the type of helpful advice I was hoping for on the forums. So this winter when I do the complete engine overhaul and I report that I was able to eek out a 3000-4000 mile riding year then will you still say "I told you so"

What I have tried to explain since the thread started is that as I understand the problem, I am endeavoring fix them. If the problem is such that I can't fix it then I will replace what is necessary. To that extent the scarred journal cap could not be repaired unless I milled the cap to allow the insertion of a milled insert. That would be most difficult but possible and I found some detailed instructions where it was done. In this case it was much easier to replace thanks to Nessism sending me a perfect fit. Thus I replaced the journal and measured everything very meticulously to insure it was a proper match. The lower journal was only slightly scarred up of which I was able to correct with about 2 hours of very light sanding and polishing. Ther is no metal or shavings and the amount of time was due to my maticulous work to insure it was done right.

I am here and I can see and feel the smoothness and I have tried with extremely close up pictures to relay those details to you all as it seems you all are as passionate about these bikes as I am. (I love the old things)

I am extremely confident that when I finish with these cams the bike will run exceptionally well and give me another great riding season.

Some day when I get the time, I will post a biography of this bike and its restoration after sitting idle for over 6 years to a bike that is ridden 6-7 days a week from mid Feb~Late Dec. Like did you guys know that Chris Vetter and his Wife were still alive and selling parts? I purchased the windshield for the ferring directly from the guy that brought fairings to the US.

 

[Nessism]

Good luck to you Roland, and I think I speak for the entire GSR in hoping you get lots of extra mileage out of your bike.

The trepidation expressed by some here is based on sound principle. That cylinder head of yours has some very serious wear. The reason valve shims are not offered in sizes smaller than 2.15 is because Suzuki knows that use of such a shim indicates an extremely sunk valve. Either the valve is mushroomed and smashed , the valve is severely sunk into the valve seat, or the cam journal is worn to the point where the cam has moved closer to the valve. In all of these cases the engine is on borrowed time and mechanically sympathetic GSR members (and I count myself as one) advocate fixing the bike properly, not sticking a bandaid on it. That said, I respect your desire to get some more ride time from the bike and salute your efforts. As said before, I suggest you get a clean used cylinder head off ebay - that's what I did recently for an engine when I found excessive wear inside. Machining the cam journals is a waste of time when the valve seats are sure to be worn and good cylinder heads can be had for less than $100 shipped.

Good luck and keep us posted on how long the engine lasts.

 

[Guest]

QUOTE=BassCliff;1023550]Oops, I didn't notice that #1 exhaust was so loose. Yes, tighten that up with a bigger shim (2.55 or 2.60) if you can. I agree with Mr. Steve, the 'x' sizes are hard to find.

But keep your eye out for a new engine, or at least a new head. Keep us informed.


Thank you for your indulgence,

BassCliff[/QUOTE]


If you need help with an "X" sized shim let me know, I'm sure I have one that will work.
check out the Shim Club thread in my sig. Ray

 

[Dan Ruddock]

Roland, I am helping you. And here is my help.
1979 Suzuki GS750 GS 750 Motorcycle Head assembly

I don"t believe in hack jobs, this is how the term "previous owner" has become a negative thing. In the time you have spent fiddling with it I would have already R&R the head and would be going down the street with no worries. Replacing a head is easy. Dan

 

[Nessism]

Roland, I am helping you. And here is my help.
1979 Suzuki GS750 GS 750 Motorcycle Head assembly

I don"t believe in hack jobs, this is how the term "previous owner" has become a negative thing. In the time you have spent fiddling with it I would have already R&R the head and would be going down the street with no worries. Replacing a head is easy. Dan

Buy It Now price of $20! Can't beat that.

Gasket kit available here... https://www.partsnmore.com/motorcycle-gasket_sets.php?make=suzuki&category=gasket_set

 

[almarconi]

Buy It Now price of $20! Can't beat that./QUOTE]

Wow that is a great deal, wish I could use it on my bike. For that price it is worth purchasing it as a spare.

 

[jjmaag]

Roland,
You may want to check the shim club for the "X" sizes. I just sent one in that was a "X" in that range, but I can't remember the exact size.

Good luck to you with this. Some people are lucky and can get a repair like this to run forever. It chaps some of us with no luck.

 

[Guest]

I'm not negative just realistic. I honesty do mean good luck when I say it.
I just know how it's going to end.
Please read my posts and then come back and tell me I have an attitude problem.
I really only want to help and maybe get a few laughs.

 

[BassCliff]

Hi Mr. chef1366,

Hey Bill, not to worry. Mr. Roland hasn't been around long enough to know that you really are a big, sweet guy, all the way down to your chewy marshmallow center!

Thank you for your indulgence,

BassCLiff

 

[Roland]

Persistance is paying off

Persistance is paying off

O.k. first the update on clearances. Followed by responses to all of today's helpful advice.

I made another trip back to my local shop swapped around my shims.
This is shim size is actual measured size not labeled size because I found the labeled sizes were not accurate enough and were pushing me just beyond spec on one side or the other 2.55x= measured 2.61mm, 2.70x=measured2.75. One more swap for #1 and I am going to seal it up and go for a nice long relaxing ride. I have been tied up in the car for 2 weeks now.
Exhaust--Shim--Gap
#1-------2.61---.o4 = too tight I am guessing it is between .02-.03
#2-------2.61---.09 = close enough at this point
#3-------2.70---.04
#4-------2.63---.07

Intake---Shim---Gap
#1------2.02----.04
#2------2.75----.04
#3------2.90----.04
#4------2.70----.04

Compression
#1 = 136
#2 = 117
#3 = 115
#4 = 120

Now for the most important, I really do appreciate all the advice and assistance and time everyone has given me on this. I know none of you have to and the only reason you do is because you are all passionate about these bikes as I am.

Nessism

such a shim indicates an extremely sunk valve. Either the valve is mushroomed and smashed , the valve is severely sunk into the valve seat, or the cam journal is worn to the point where the cam has moved closer to the valve.

As an engineer my brain and thought patterns are completely unable to accept giving up on fixing a problem until I know exactly the cause. I also can not accept "it's junk" whether true or not unless I also know why it is junk. Until then, I fix what I can in a very methodical manner in an attempt to cure the problem.

The sunk in valve idea makes extremely good sense and would appear to the most likely scenario that would cause the tappet clearance to go beyond specification. This in turn would cause the Top Journal Cap to become worn which caused the journal gap that I initially came across. It took 2 weeks get to this result but it really does make sense.

If the engine does or doesn't make it to the winter I will be certain to let you all know, but I very much suspect it will be a very nice summer at which time I will hopefully make a much smaller post of a simple head rebuild and replacement.

Thanks Ghost for the Shim Offer. I just read through your posts on the Shim Exchange. I didn't know anyone was doing this very nice. I am almost done now and I will send you my extras for the kit.
I noticed on May 1, 2008 you posted you were going to retire and would no longer have access to the machine shop. I have access to an exceptionally good Mechanical Engineering machine shop at the college that I work. If you need any of the shims ground down to precision I can get it done to an accuracy somewhere around .00001mm. The only draw back is they do not have a tempering area.

Thanks Dan
The head looks like a good buy <fingers crossed>I did just purchase that head. It should be here in about 9 days. If I have trouble before the winter then I will install it then otherwise I will disassemble it and get it ready for my winter rebuild.

Subtotal:US $19.99

Shipping & handling:US $27.88

Total:US $47.87

Sorry Chef I know you are not normally negative and you have tried to help it was just the "Junk" comment when I have been working so long and hard to complete what should have been a simple singe afternoon project. I'm a guy that rides 7 days a week rain or shine and I guess not riding is starting to get to me.

I have been on the forums for longer than you guys may know. I think it has been at least 3-4 years now. I do a lot more reading than I do posting well at least until this project. Unfortunately I had an exceptionally bad year last year which put me off the forums for about 8 months and all my previous posts appear to have been deleted.

 

[first timer]

I just want to restate it is not a good idea to grind shims, it removes the tempered shell.

Secondly you don't have to be supper anal with your shims sizes it's better to be loose on a shim (with in reason) then tight, sometimes there just isn't a shim that gets you right in the middle. If I was you I would error on the side of the looser spec according to Suzuki.

what cause a loose shim is the top of the valve stem wearing down and letting the bucket go deeper in the head. what causes a tight shim is valve edge surface wearing or valve guide surface wearing or both and the valve spring pushing the valve stem closer to the cam lobe.

What nessim is just saying is logically speaking if your shim size is so small some thing has happened either the valve seat/guide is worn and pushing the valve stem closer to the cam or your cam has been pushed closer to the valve stem. Either way both Nessim and myself who are also engineers are concerned because what ever has happened has caused the head to go beyond designed specs which is not a good thing in the engineering world.

Your engine will still work probably it just won't be at top performance and things will just wear at a exponential rate since it is no longer in tolerance.

Enjoy your summer just do yourself a favor and keep checking your clearances every 500 miles so you don't damage anything else so you can do the head replacement in the winter.

Cover both sides of your oem valve gasket with some good grease ? this will let you keep reusing it.

 

[gearhead13]

Cover both sides of your oem valve gasket with some good grease ? this will let you keep reusing it.

My way of doing this is to use silicone on the cover to hold the gasket in place on the cover, then next time you remove it it sticks to the cover in perfect position.
Richard

 

[first timer]

My way of doing this is to use silicone on the cover to hold the gasket in place on the cover, then next time you remove it it sticks to the cover in perfect position.
Richard

I am sorry but me and many others will agree; silicone is just a bad idea, it makes a mess and can break apart and clog oil ports. If yo uuse wheel bearing grease, it is tacky enough to hold the gasket in place and there is no need for silicone, rtv or what ever you call it.

 

[Nessism]

My way of doing this is to use silicone on the cover to hold the gasket in place on the cover, then next time you remove it it sticks to the cover in perfect position.
Richard

I think this is a good idea only Threebond 1184 is preferred over silicone and make sure to only use it on the cover side.