Re: Cam Chain Tensioner On These Old Bikes?

[joejeweler]

I read with interest another poster describing a bit of clatter upon startup, that goes away later as the bike works up.

http://www.thegsresources.com/_forum/showthread.php?t=194059&page=2

I have noticed a bit of that myself, and have likewise suspected the cam chain tensioner as it's sounding from that general area.

My '82 GS850GL has about 14,300 miles on her now,......and i can't imagine the camchain is worn out? As the clanking sound is only there a short while on startup (noticable with a slight roll-on of the throttle mostly), and then goes away as the engine warms up.....i haven't been overly concerned at this point.

I've put the last 5000 miles on the bike over 6 years (last 3 yrs bike was stored up) and have pretty much always used Mobil 1 synthetic, (uaually the 4T racing bike oil, but if they were out i've had no problem with the Mobil 1 High Mileage synthetic. It has no friction modifiers as i understand it, and figured the seal conditioners might be a good thing on the 30 year old seals. So far not a single oil leak anywhere, and no slippage at the clutch with the original plates/springs!

I have yet to look into the proceedure to possibly adjust the cam chain tensioner, although i understood it to be "automatic"?

In going over the Haynes manual for this bike, i found it interesting there is a "chain guide blade" and a "chain tensioner blade" as part of the cam chain tensioner system.

BOTH blades, from what they describe, are steel with a rubber backing which must wear (or simply degrade over time). I'm wondering if these old girls,....mine being 30 years old now, have a history of the rubber backing on the steel blades breaking down over this time period. (even without heavy miles being put on?)

Any opinions based on personal experience with this group of parts going bad over decades of imersion in oil, hear, and time would be most appreciated.

Also, are any of these parts accessible for replacement without an upper end teardown?

.....just trying to get a feel as to what others have done to address this?

[Nessism]

The number one resource you should use to figure out what's wrong with your bike is the search feature here. Click Advanced Search. Type "tensioner" in the search field then toggle "titles only" and start reading. There is tons of info on this subject, including a tutorial on how to replace the seals and rebuild it. There is nothing wrong with your tensioner blades and no they don't wear out, except with 100,000+ miles on them.

Oh, and get a proper Suzuki manual off Cliff's web site. Haynes manuals are better than nothing, but just barely.

[BassCliff]

Hi,

It's a slow day at work and I'm in a good mood today. I'll make it easy for you.

Cam Chain Tensioner Repair

Reset Cam Chain Tensioner

Replace seals in cam chain tensioner



The cylinders must be removed to access the internal cam chain tensioner parts. But you must really abuse your engine for these not to last 100,000 miles.

One more link (right-click and "Save as..."):

Download a Suzuki GS850G Shop Manual (155MB)


Thank you for your indulgence,

BassCliff

[Big T]

You are right - it's not worn out.

It's over 30 years old and the seals have gone bad from old age and lack of use. Ditto the tensionser itself.

Do the tensioner rebuild and you'll be fine

You do have to tear down the top end to replace the blades

[gearhead13]

My thoughts on this. I have a manual chain tensioner and have replaced both front and rear guides. My valve clearances are set properly as well. It still rattles. I'm used to it, but it bothers me.
I say to myself "If I was looking to buy a new bike (in 1982) and it rattled like that, would I really buy it?"

[joejeweler]

You are right - it's not worn out.

It's over 30 years old and the seals have gone bad from old age and lack of use. Ditto the tensionser itself.

Do the tensioner rebuild and you'll be fine

You do have to tear down the top end to replace the blades

I'll pick up some new seals and schedule in a rebuild at some point, but i am curious about something.

Age gets us all, but do old seals prevent the tensioner form working properly? As i have no oil leaks, i was hoping to maybe try a simpler reset of the tensioner, which might loosen the plunger up if it now sticking a bit

New seals would then be installed over the winter down time here in the north east NY.

.....or am i missing something?




Cliff,...much appreciated! Hope to catch you in many a good mood day!

I'm going to try the reset proceedure soon!

Hi,

It's a slow day at work and I'm in a good mood today. I'll make it easy for you.

Cam Chain Tensioner Repair

Reset Cam Chain Tensioner

Replace seals in cam chain tensioner



The cylinders must be removed to access the internal cam chain tensioner parts. But you must really abuse your engine for these not to last 100,000 miles.

One more link (right-click and "Save as..."):

Download a Suzuki GS850G Shop Manual (155MB)


Thank you for your indulgence,

BassCliff

[tkent02]

The ones I've taken apart the guides were fine, even the 120,000 mile one.

[Nessism]

Set the engine at 1-4 T (TDC)

Remove tensioner

Play with it until you figure out how it works, then wind it up by turning the knob and pushing in the plunger.

When you let go of the plunger and knob the plunger should shoot out with some good force until the end of travel is reached.

If the plunger does not shoot out as stated, something is wrong.

Assuming all is good, cut a new gasket from gasket paper and reinstall the tensioner after winding it in and setting the set-screw.

Once the tensioner is installed, release the set screw and listen for the plunger to shoot out and tension the cam chain.

Last step is to tighten the lock nut after you back off the set-screw about 1 turn.

I recommend you double check the cam chain timing and turn the engine over one turn by hand just to be sure the timing hasn't jumped.

Not sure why I'm writing all this, it's in the archives in various threads. I'm no Cliff and don't like spoon feeding.

[joejeweler]

Set the engine at 1-4 T (TDC)

Remove tensioner

Play with it until you figure out how it works, then wind it up by turning the knob and pushing in the plunger.

When you let go of the plunger and knob the plunger should shoot out with some good force until the end of travel is reached.

If the plunger does not shoot out as stated, something is wrong.

Assuming all is good, cut a new gasket from gasket paper and reinstall the tensioner after winding it in and setting the set-screw.

Once the tensioner is installed, release the set screw and listen for the plunger to shoot out and tension the cam chain.

Last step is to tighten the lock nut after you back off the set-screw about 1 turn.

I recommend you double check the cam chain timing and turn the engine over one turn by hand just to be sure the timing hasn't jumped.

Not sure why I'm writing all this, it's in the archives in various threads. I'm no Cliff and don't like spoon feeding.

Thanks,....i just went out and took a quick look at it. Seems a shame the designers didn't make this resettable while on the bike. The adjustment screw and nut face the right way to easily get at them.

I guess a tensioner reset is not possible while mounted?

It does look "possible" to remove the tensioner unit without carb removal, but a tight area for sure. I just replaced the fuel line going from my brand new petcock to the between the carb "T". What a PITA!

The Suzi dealer only had a thin clear line,.....didn't really trust the clear stuff. The auto stores only carry the thick reinforced black line needed for presurized systems, but only had 1/4" and 5'16" ID stuff. The 1/4" was a little too small to get on either end, and the 5/16" ID hose a bit loose on the "T", probably OK on the petcock.

What i did was use my jewelry repair flexshaft, & fit a diamond setting bur and lightly reamed out both ends of the hose to an in-between measurment that was much snugger on the composite carb "T" than the 5/16" hose, and tighter yet on the metal petcock end but not a real problem. I used really long needle nose pliers to get the hose in between the carbs for now (covered the sharp plier edges with masking tape) , and will add a spring clamp at next carb removal at the "T" end,.......

........mayber sooner than later with this tensioner issue!



I'd almost prefer a simpler manual adjuster that every 2000 miles you loosten a locknut, a spring loaded adjuster pops out (having a proper relief so as not to be too tight), and then retighten the lock nut. Seems i had that on one of my three 1979 Hunda XL500S duel purpose over the years.

[sedelen]

I guess a tensioner reset is not possible while mounted?

No, you have to push in on the plunger rod while cranking back on the adjuster knob, all the way in, then tighten the set screw hard enough to where the plunger stays in. You need it all the way in or else the tensioner assembly will not go all the way into it's mount.

[rustybronco]

Thanks,....i just went out and took a quick look at it. Seems a shame the designers didn't make this resettable while on the bike.

Why would you need to have it resettable? It automatically adjusts (extends) for wear.

It does look "possible" to remove the tensioner unit without carb removal, but a tight area for sure. I just replaced the fuel line going from my brand new petcock to the between the carb "T". What a PITA!

On your bike it takes 40 minutes to remove and replace the tensioner including air cleaner and carbs.

The auto stores only carry the thick reinforced black line needed for presurized systems, but only had 1/4" and 5'16" ID stuff. The 1/4" was a little too small to get on either end, and the 5/16" ID hose a bit loose on the "T", probably OK on the petcock.

1/4" fuel line fits just fine. I just used it on my 80 '850 and Stans 83 1100GK within the past two weeks.

What i did was use my jewelry repair flexshaft, & fit a diamond setting bur and lightly reamed out both ends of the hose..

Next time slip a set of needle nose pliers into the end of the 1/4" hose and open them up. it gives just enough stretch to hose so it will go over on that tee fitting between the carbs.

[joejeweler]

Why would you need to have it resettable? It automatically adjusts (extends) for wear.

On your bike it takes 40 minutes to remove and replace the tensioner including air cleaner and carbs.

1/4" fuel line fits just fine. I just used it on my 80 '850 and Stans 83 1100GK within the past two weeks.


Next time slip a set of needle nose pliers into the end of the 1/4" hose and open them up. it gives just enough stretch to hose so it will go over on that tee fitting between the carbs.

I only enlarged the 1st 3/8" or so on each hose hole end, and had the hose cut a
bit long so when i do get the carbs off i can cut that part off. (about 12", 2" longer than what was there before)

Also, the diamond setting burs cut a smooth channel, and as a bench jewelry repairman/diamond setter for 35 years, i have a keen eye and steady hand! I have a tapered mandrel i could have used to stretch the hose also, (small one i used to make jump rings out of gold wire), but i didn't want to lose any "stretch" in the hose. Wish the "T" between the carbs was brass though, not sure how much pressure it would take in pressing the hose on?

The auto adjuster works fine, until it doesn't. I'll probably wait until i get some parts in, and then rebuild it a bit at the same time i reset it.

Oh,....it might take YOU 40 minutes to remove the carb, airbox, and tensioner. I'm sure i'll take a bit longer to clean up the area, and there's always something else to check out on these old girls while being "intimate" with them!

[tkent02]

I prefer an automatic one that doesn't need to be messed with for 100,000 miles or so, but if you want an extra knob to play with go ahead.

[Steve]

Oh,....it might take YOU 40 minutes to remove the carb, airbox, and tensioner. I'm sure i'll take a bit longer to clean up the area, and there's always something else to check out on these old girls while being "intimate" with them!

Send me some contact information.

I am heading back to upstate Vermont and New York for the next couple of months, I can probably stop over and show you how to do it in half an hour.

.

[joejeweler]

I prefer an automatic one that doesn't need to be messed with for 100,000 miles or so, but if you want an extra knob to play with go ahead.

Heheh,....so would i, but seeing how i only have 14,300 miles on the bike, doesn't seem like it worked!

I understand about age being a factor, but the unit does bathe in an oil so lubrication about the best of most anything in the internals.

Not sure if a dry o-ring can cause them to malfunction either

Send me some contact information.

I am heading back to upstate Vermont and New York for the next couple of months, I can probably stop over and show you how to do it in half an hour.

.

Hi Steve,thanks for the offer,....but i was making a bit of a joke in that i always seem to get a bit sidetracked working on one thing, and seeing something else that could use a bit of attention or a good cleaning.

So one job often ends up a multiplicity of "fun".

.......i do believe if i stuck to "just" the job at hand, i could get the carbs and airbox out in a half hour. I also like to take notes on paper about where different lines, cables, or hoses go for reassembly, and that does eat some time.

Otherwise......just might take a little longer to get her all back together!