Identify Part?! 81 GS 850

[slaveforthewave]

First things first... First post! So hey to everybody!

I have been reading this site religiously, with the addition to the basscliff site, and have yet to actually have to ask my own question... so far. Nearly everything is covered between the two.

But I have run into a bit of a problem that I am having trouble overcoming. I got a 81 GS 850 about 2 months ago. The thing drove but had oil all around the engine and the flat spots were terrible. Checked the oil... full of gas. Decided to take the thing apart, hard tail it, rebuild the top end of the engine and carbs, and make this thing an acceptable ride.

Hard tail is done, all new gaskets are in (after dealing with two stripped cam bolts), but as I was timing the cams I realized that I had no idea how these little black runners that the timing chain run on went back in. I looked in my manual, searched up and down and nothing. Finally i got a flashlight down into the timing chain hole that runs through the middle of the block and saw two little semicircular pieces of 1/8" or 1/16" aluminum that were broken off and just hanging out down in the hole. I tried to snap a picture but it was hard to focus the camera down that deep crevice.

So, my question is does anyone have any idea how the two black timing chain runners mount? Is there some sort of bracket down in the hole that I broke off somehow? And are they absolutely necessary? Can I run with out them? I really would like to not have to unbolt the heads and take everything apart again if i can just wiggle those pieces of aluminum out with a dowel and some rtv on the end.

If the picture is clear to anyone the pieces I am talking about are to the left and right of that screw.

Thanks,
David

[Nessism]

The forward cam chain blade tucks into slots in the head on top, and into that bolt-on guide shown in the photo on the bottom. The rear tensioner assembly is bolted into the engine at the bottom and you need to pull the cylinder off to access it. Can't tell from your photo but if both tensioner guides are loose you are in trouble.

[BassCliff]

Greetings and Salutations!!

Hi Mr. slaveforthewave,

Sorry, I have no experience with your cam chain guide issue, but here's your "mega-welcome". I can't help myself, it's "my thing".

I just stopped by to welcome you to the forum in my own, special way.

If there's anything you'd like to know about the Suzuki GS model bikes, and most others actually, you've come to the right place. There's a lot of knowledge and experience here in the community. Come on in and let me say "HOoooowwwDY!"....

Here is your very own magical, mystical, mythical, mind-expanding "mega-welcome". Please take notice of the "Top 10 Common Issues", the Carb Rebuild Series, and the Stator Papers. Now let me roll out the welcome mat for you...

Please click here for your mega-welcome, chock full of tips, suggestions, links to vendors, and other information. Then feel free to visit my little BikeCliff website where I've been collecting the wisdom of this generous community. Don't forget, we like pictures! Not you, your bike!

Thanks for joining us. Keep us informed.

Thank you for your indulgence,

BassCliff

[bwringer]

Here's the relevant fiche:

http://www.partshark.com/fiche_section_detail.asp?section=95161&category=Motorcycles&make=SUZUKI&year=1980&fveh=2142

This diagram might appear if PSN allows image linking...


As for your photo -- which way is the front of the engine? Are we looking down into the front of the engine with the forward cam chain guide (part 2 on the diagram) removed?

Obviously, there shouldn't be any loose pieces in there. It appears that a piece has broken off the aluminum lower guide (part 3). This probably happened because the cam chain got bunched up and then forced to rotate backwards at some point.

If this is the case, I don't think the forward cam chain guide will seat in a stable way -- it appears that the guide will contact the chain and probably cause Big Problems in a hurry. Unfortunately, the crankshaft has to come out in order to replace the lower guide.

Fortunately, it is possible to disassemble to bottom end of the engine without removing the cylinder head and block. You also don't necessarily need to completely disassemble the transmission in the process, although you will need to replace a few transmission seals and the crankshaft seal while you're at it.

It's certainly do-able even if you're not all that experienced.

[bwringer]

To clarify whether you need to fix this, you'll need to determine whether you can get the bottom part of the forward cam chain guide to seat in a stable way with part of the lower guide missing. I'm thinking it won't work, but it's hard to tell from one photo.

I'm looking for a photo from a valve adjustment that will show how the top end of the forward cam chain guide tucks into the cylinder head. Poke around and you'll probably find it, or there might be a photo in the shop manual.

When you install the forward cam chain guide, the bottom end is held sort of firmly in the slot at the bottom, and you have to put a slight amount of tension on the blade to tuck it into the slot at the top and push it down into the slot at the top. If this slight tension is not present, you'll need to replace the broken bottom guide. From what I see, I think the bottom end of the forward guide will be a bit loose.



Just FYI, here are some photos of a GS850 bottom end in the process of assembly:

Here's the bottom half of the case -- you can just barely see the bottom cam chain guide at the top of the photo:



Here's the top half of the case, flipped upside-down and ready to install the bottom half:


The full gallery:

http://www.pix.bwringer.com/v/bwringer/79_850_Engine/

[slaveforthewave]

Thanks so much for the knowledge, guys! Once I had a name for it I pulled up a fiche and found out that the part had been discontinued. Great. Start the hunt.

The side that appears to be broken is only the front of the engine. The other side, that the tensioner pushes on, appears to be snug and in place. There isn't too much room for the front blade to move around... Since it is not the tensioner side do you think i will be able to get away with it?

[tatu]

The side that appears to be broken is only the front of the engine. The other side, that the tensioner pushes on, appears to be snug and in place. There isn't too much room for the front blade to move around... Since it is not the tensioner side do you think i will be able to get away with it?

No.

How did the original bits get broken?

[slaveforthewave]

Well, this has been my first real eff up on my build... Now to fix it. I'm not really looking forward to taking the bottom of the motor apart to be honest, but it does appear that the sprocket is in the way of removing that aluminum piece....


I'm assuming, as bwringer said, the chain probably got bunched up and as I was either putting the pistons back in the jugs or messing with the cams I backed up the motor accidentally and broke the ears off of that aluminum "cam chain guide holder" as the fiche likes to call it.

[wdavie]

Hi mate if you still need the part I believe there is a one for sale on ebay in the UK number 110597842414. Cheers Wayne

[bwringer]

Hmmm...

Well, the cam chain guide I pulled out of my bad engine turned out to be damaged as well.

So. Let's try to find a new one.

The part number is: 12776-45001

This part seems to be common to the early GS750 (76-79) and all GS850 models. The same part number also appears in fiches for the early GS400 and 425.

GS400X (1977)
GS400X (1978)
GS425E (1979)
GS425L (1979)
GS750B (1977)
GS750B (1978)
GS750B (1979)
GS750C (1977)

Now, here's the kooky part: when you go to the fiches for the GS400/425, the part is showing that it's available.

Some suppliers are showing the part as NLA for the 850, but available for the 425/400. I don't know what's up with that.

In sum, go ahead and try to order one. You might just be able to get one.

[slaveforthewave]

I had that part number from the fiche I looked up earlier. Unfortunately I called two local Suzuki dealerships and they told me the part was discontinued. But I found a nice parts guy at Motorsports of Tampa who did a national look up and told me that there were two Suzuki dealerships in the country that had NOS.

So for anyone who might need this part,
Mid Ohio Suzuki can be reached at 740.397.5272 and has 3 of them left.
King Cycles can be reached at 718.773.2279 and has 2 of them.


Thanks So Much Brian!!


-David

[BassCliff]

Hi,

I'm just curious. How much are they selling that NOS part for?



Thank you for your indulgence,

BassCliff

[slaveforthewave]

Well the total came out to 12 and change shipped to Central Florida from Ohio. I didn't ask how much the holder was by itself, but somewhere around 5-7 bucks I would guess.