Shim size going up?!?

[esmithers]

Anyone encounter a problem with clearance from stock being the opposite of tight but too wide. Ask due to from all accounts my bike has never been serviced and well the number 1 and 2 clearances are way off as far as thickness compared to the other clearances. Would you feel it would be wise to bring all to the same consistent range?

 

[Brendan W]

Never been serviced is kinda all bets off territory. Normally you expect clearances to change because valve seat wear will tighten and cam/bucket/pushrod/shim wear will open. When you say 1 & 2 is that inlet and exhaust on 1 and 2?
How exactly are you checking? Are you doing two valves at a time or going for cam pointing up?
Gut reaction, if someone told me their bike never got serviced and the clearances were opening up I'd be thinking the oil was so bad the cam lobes and such were wearing fast. If they then said it was only 1 & 2 I'd be thinking the cam bearings were shot on that side.

 

[tkent02]

The clearances usually get smaller, but not always. Sometimes they get bigger.

Or maybe someone did get in there and did something wrong.

Put them in spec and ride it.

 

[esmithers]

Well if you review a post i posted in the carbs section.. i am having the problems with the number 1 and 2 (left side of bike as you sit on it) exhaust pipes not getting hot.. after having the Carbs service and rebuilt to include o-rings from Chef.. additionally, I have taken them off and left them soaking for 2 days to ensure they are clean to include 110-120 PSI pushing air through everything.. the carbs are spotless.. the tank is like new on the inside and no rust.

when i originally checked them, i incorrectly checked them obvious. and when i split that top off it was near welded on the head. so i assume no maintenance was performed (also the bike is rolling at 13,100 miles on ODO)

So i know fuel is getting to the carbs and with the colortune on the bike you can see sporatic (every 10-20 secs you see a flash of bright red) indicating not none to little fuel getting in the carb or exhaust is stuck open.

What has been replaced and checked...
New (used, tested and checked) coils, plug wires and caps
New Plugs, gapped.
Carbs cleaned w/ new seals
flipped the plug wires and no change (number 2 to 1, 3 to 4, 1 to 2, 4 to 3)

So all i can think is that the valves are not opening or stuck open. pulled the valve cover off, brought the cam lobe pointing up towards sky and check each valve including moving the buckets..

Buckets are freely moving, so i know its not stuck open.. so i checked the clearance and have over .10 on them seeing how my blade only goes to .10 and it freely moves with no resistance. if i remember correctly those that were loose were Intake #1 and Exhaust #2. Intake on # were .06 and exhaust #1 was .03

Let me know what you think. I HATE SHIMS! i rather have hydraulics and or adjustable tappets.

 

[tkent02]

Got compression?

 

[Steve]

... after having the Carbs service and rebuilt to include o-rings from Chef.. additionally, I have taken them off and left them soaking for 2 days to ensure they are clean ...

Hold on just a minute. Are you saying that you just had Chef rebuild your carbs, then soaked them again, yourself?
Did you totally dis-assemble them before dipping them or did you leave them assembled?

flipped the plug wires and no change (number 2 to 1, 3 to 4, 1 to 2, 4 to 3)

All that wire-switching makes me ask ... do you have the correct wires on the plugs?
You can't simply move them around the way you did, unless you also switched the wires from the coils to the ignitor.

The LEFT coil is normally connected to plugs 1 and 4, the RIGHT coil is connected to plugs 2 and 3.

If you want to move wires around to diagnose a problem, you swap 1&4 and you swap 2&3. If you move #1 to #2 or #3, it will be out of phase and fire at the wrong time.

So all i can think is that the valves are not opening or stuck open. pulled the valve cover off, brought the cam lobe pointing up towards sky and check each valve including moving the buckets.. .

Now you need to go back and check them properly. I know that the instructions are a bit confusing in all three manuals (Suzuki, Clymer and Haynes).

If you start with the exhaust valves on 1 and 2, you align the cam lobes so EX1 is pointing forward, EX2 is pointing up.
Without moving anything, check BOTH valves, EX1 and EX2.

Rotate the crank 180 degrees (1/2 turn), you will see that the lobe on IN1 is pointing up, IN2 is pointing rearward.
Without moving anything, check BOTH valves, IN1 and IN2.

Rotate the crank another 180 degrees, you will see that EX4 is pointing forward, EX3 is pointing up.
Without moving anything (do you see a pattern here?), check BOTH valves, EX3 and EX4.

Rotate the crank a final 180 degrees, you will see that IN4 is pointing up, IN3 is pointing rearward.
Without moving anything, check BOTH valves, IN3 and IN4.

All of the manuals show the cam lobe positions, but what they don't explain very well is that you check both valves at the same time.

.

 

[lemonshindig]

Now you need to go back and check them properly. I know that the instructions are a bit confusing in all three manuals (Suzuki, Clymer and Haynes).

If you start with the exhaust valves on 1 and 2, you align the cam lobes so EX1 is pointing forward, EX2 is pointing up.
Without moving anything, check BOTH valves, EX1 and EX2.

Rotate the crank 180 degrees (1/2 turn), you will see that the lobe on IN1 is pointing up, IN2 is pointing rearward.
Without moving anything, check BOTH valves, IN1 and IN2.

Rotate the crank another 180 degrees, you will see that EX4 is pointing forward, EX3 is pointing up.
Without moving anything (do you see a pattern here?), check BOTH valves, EX3 and EX4.

Rotate the crank a final 180 degrees, you will see that IN4 is pointing up, IN3 is pointing rearward.
Without moving anything, check BOTH valves, IN3 and IN4.

All of the manuals show the cam lobe positions, but what they don't explain very well is that you check both valves at the same time.

.

Can you confirm that this makes a difference? Without checking myself, I'm willing to bet that you can check it per the manual or by putting the lobe up and get the exact same number. I bet the manual is written that way with the intention of making it easier to check the clearances, not because it won't work if you check them all vertical.

 

[tkent02]

No, it comes out different.

 

[esmithers]

Okay, to clear any confusion.. I have rebuilt a 85 Suzuki Madura GV1200 without a hiccup and have additionally performed periodic maintenance on various Metric cruiser/sports. but with every bike, lies different sets of problems.

The coil wire were switch as if you were to physically remove the coil and change the side. if you were to shift the wires left you would still have it correctly hooked up. 1 goes to 4, 4 goes to 3, 3 goes to 2 and 2 goes to one. you sill have the 1-4,2-3 setup.

Bike had compression at 110 Psi being the lowest the rest average at 115 (note this was taken when first got the bike) will have to borrow/buy another tester to check again.

the Carbs were fully disassembled and soaked. i would not soak, plastic or rubber. thats a rookie and pricey mistake that i am not glad to make ever again. so no they were properly removed and cleaned to ensure and compound the cleaning from Chef.

Lastly.. the shims or valves are adjusted on the rest side of the lobe. this is commonly found through all applications to include automotive. so with the lobe of the cam to the 180 degrees from full contact is the proper and most efficient way of checking clearance between the valve lash/shim. if this is this incorrect them i am dealing with a very and i mean very unique machine.

I will just remove the shims, annotate the number corresponding the cylinder and note what are out of spec and go from there in getting proper adjustment of these valves. i will figure this out one way or another even if i have to pull the motor apart. this bike will not get the best of me. Just first time i have seen a shim so small compared to the rest of the bike.

P.S. forgot to add. I have stock setup on this bike, i believe to best bring everything back to stock and then improve from there.

So the air box and assembly is air tight minus the stock air flow holes on the side of the box. and have brand new seals in the intake boots aswell.

 

[lemonshindig]

You're coming off as challenging the advice handed to you...

What they have said, the procedure for checking the valve shims, is EXACTLY how the manual describes it. They didn't make it up. For what it's worth, I did mine with the cam lobs pointing up and my bike has outstanding compression.

And yes, it would be wise to adjust the valves. That was your original question, wasn't it? You're talking now as if you're a bike expert but you're asking us if you should adjust the one valve that is out of spec...?

Yes. Adjust the valves. If your valves have excessive clearance, then they won't open very well, now will they?

Once again, the way they describe to you for checking valves is what the manual says, so don't question their intent. I however believe that adjusting them cab lobe up won't hurt a thing.

 

[tkent02]

If you want to do a lot more work to get worse measurements, that's fine with me.

 

[esmithers]

I was only applying the logical explanation without getting too complicated. Not a challenge. I only state to prevent a long drawn out session. I was asking what have those who are on here witness such poorly built or adjusted valves. Question was to find out if this was a common trend with these bikes or was this something that just happen.

if you put facts with logic you will come to the question of how this bike ran for so long to elicit such a major clearance issue. understandable with adjustable valves but this is user error or manufacture error.

I did not imply i was an expert. i stated that i have extensive experience working on Metric bikes and Harleys. But there is room for human error and misdiagnoses. I stated what i did and i get requestioned on non-issues and measures taken. this is a common trend in this forum.

I am not looking to **** off people, just looking to find a decent plausible answer to a question.

for the sake of the trend, I have follow the MMI program to ascertain the deduction of problems i have encounter. I have cleaned the carbs to standard, the coils, plugs, wires, compression, and went as far as the 12V relay trick (great idea that i learned and will forever use hence forth). i have spark, compression, Air, and fuel flow. now its a matter of enough fuel entering the combustion chamber ignite the explosion.

as i stated, i will not give up because i have gotten this far.

So if you offended by my comments your perception is off.. i am not looking for the tire kicking responses when i have established that i have diagnosed down to the valves. if the clearance is not it. then i will recheck compression and end removing the head to check burnt valves and relapping them

 

[Steve]

The coil wire were switch as if you were to physically remove the coil and change the side. if you were to shift the wires left you would still have it correctly hooked up. 1 goes to 4, 4 goes to 3, 3 goes to 2 and 2 goes to one. you sill have the 1-4,2-3 setup.

I might be the one missing something here, but if you move all the wires one space to the left, you will only have two plugs firing at the correct time.

By moving the wires one space to the left (and moving #1 to #4), the left coil, which is supposed to fire plugs 1 and 4, will be firing 3 and 4. The right coil, which is supposed to be firing 2 and 3, will be firing 1 and 2.

You will NOT have correct firing by doing this.

Lastly.. the shims or valves are adjusted on the rest side of the lobe. this is commonly found through all applications to include automotive. so with the lobe of the cam to the 180 degrees from full contact is the proper and most efficient way of checking clearance between the valve lash/shim. if this is this incorrect them i am dealing with a very and i mean very unique machine.

Not really all that unique. The reasoning behind these particular positions is that when the lobes are in the proper position, neither one on that side of the engine is pushing on a valve. That ensures that the cam is not displaced in the bearing, giving you more-consistent measurements. If you move the cam lobe to face away from the valve, one valve on that side will be depressed, the other will not, this will give "extra clearance" on the valve you are checking. THAT MIGHT BE YOUR PROBLEM that started this thread.

I will just remove the shims, annotate the number corresponding the cylinder and note what are out of spec and go from there in getting proper adjustment of these valves.

Before you do anything drastic, please be aware: DO NOT MOVE THE CRANK IF ANY SHIMS ARE REMOVED. The cam lobe will be scraped up by the sharp edges of the shim bucket, leaving chips and shavings in your engine. Remove one shim, inspect it, put it back in place before turning the crank. If you insist on removing more than one at a time, use something in place of a shim. Some have used coins with apparent success. Since you will not be running the engine with the coins in place, clearance is not an issue, neither is the fact that the coin does not completely cover the bucket.


We are not trying to pick on you, it's just that you seem to be resisting the information that is being presented. These are not "suggestions", they are the factory-recommended way to do the job properly. Besides, it works.

.

 

[tom203]

as Steve said..."Not really all that unique. The reasoning behind these particular positions is that when the lobes are in the proper position, neither one on that side of the engine is pushing on a valve. That ensures that the cam is not displaced in the bearing, giving you more-consistent measurements. If you move the cam lobe to face away from the valve, one valve on that side will be depressed, the other will not, this will give "extra clearance" on the valve you are checking. THAT MIGHT BE YOUR PROBLEM that started this thread"

The neighboring cam lobe can give you false clearance as the camshaft is pushed up in its bearing but I doubt it would be even .005 inch. I'm sure this thing would start and run with.020 valve clearance. Get the coils wires back on right plugs, check for spark, make sure you got fuel in bowls, etc.
This bike will start and run at least to 3k rpm or so without a filter element ( Mine did when I bought it in 25 degrees), so don't fret. I'm sure your carbs are cleaned decently- likely better than most- so get back to basics.

 

[Brendan W]

The valve check procedure for the 850 looked strange to me initially. I had always gone for cam lobe up. I checked a few numbers to see what truth there might be in this odd way of checking and this is what I came up with - ball park figures ok. thou inch
Z650 valves 3 to 7
GS850 valves 1 to 3 that's close
Typical GS camshaft journal clearance new 2 - 3 , service limit 6. For me there is the probability that new or thirty years old a GS has enough journal clearance to significantly affect the measured valve clearances depending on whether it's being lifted by a spring or not and that's good enough for me for now.
You could probably argue that with a horizontal lobe you're not at full clearance and maybe you'd be right but I reckon the guys who built these things knew a thing or two and the clearances specified are for both cams unloaded.

 

[bwringer]

Unite your units, please...

Unite your units, please...

Let's back up a bit. Are you working in inches or millimeters? I see people in this thread mixing units, and that's a great way to get confused.

The correct clearances on an 8 valve GS are .03 to .08mm. It's fine to go up to .10mm, and if your clearances are .03 - .04mm, you should probably change the shim anyway, since they tend to tighten over time.

And yes, these clearances are TINY compared to most engines.

.03mm = 0.0012 inch
.08mm = 0.0031 inch

.003" = .076mm
.008" = .203mm

I have seen clearances set WAY too wide by people who get confused and mix "thousandths of an inch" with "hundredths of a mm". So perhaps that's something a PO did, and may explain what you're seeing.

Most inch sets don't even have an .001" blade, so if all you have is an inch set, you'll probably only have one or two blades in the correct range. A metric set will have more blades in the correct range and costs less than $10.


Shims are dead easy compared to diddling screw and locknut tappets, and wondering if and when one of the locknuts is going to come loose. Shims also hold adjustment longer. I will freely admit that building up a collection of shims is a bit of a pain, though.

 

[tom203]

"Typical GS camshaft journal clearance new 2 - 3 , service limit 6. For me there is the probability that new or thirty years old a GS has enough journal clearance to significantly affect the measured valve clearances depending on whether it's being lifted by a spring or not and that's good enough for me for now."

You are overthinking this! lots of these cam journals probably see 100k without any problems.

 

[tkent02]

You are overthinking this! lots of these cam journals probably see 100k without any problems.

A lot more than that if they have oil the whole time.

 

[chuck hahn]

I wondering the same thing about the feeler gauges....use metric ones.

 

[chuck hahn]

Hows the exhaust on the left side? Collapsed baffles of mice nests in there causing serious restrictions???? Cant suck in gas if it can expel the air in the cylinders..............Maybe take that side off and run a garden hose in there and flush it real good?