Missing Parts and Other New To Me Woes

[rustyspoon]

Hey all!

I just picked myself up a 1981 GS650G (non-Katana)! When I got it it needed a new battery but would start and run if jumped or bumped. However, it would stall whenever I pulled in the clutch with no throttle input. My first thought was carbs, but after reading through this topic:

https://www.thegsresources.com/_forum/forum/technical-forums/popular-technical-info/18300-still-won-t-idle-i-think-i-m-done

I'm fairly convinced the stalling is a valve issue that requires clearance checks.

Anyway, I pulled the carbs and used carb cleaner through all the nooks and crannies. It was running before I pulled them, so I thought it would be enough to unstick whatever it was that was clogging it up. But now it won't start. Starter fluid will get it running for a bit, but it immediately dies. Does anyone have a video or guide on disassembling these particular carbs? I'm fairly new at this, and I'm rather apprehensive about breaking something or forgetting a brass fitting when I put them in the dip.

On another note, where can I find the model for my particular carbs? When I took them apart for the spray, I noticed that two of the four air mixture screws were missing their springs and three of them were missing their o-rings and I want to make sure I get the right ones

I've also changed all the fluids.

[Suzukian]

You need the Factory Manual and follow the instructions. It will be the best investment you make. you will be able to post less generalized questions then. Many bikes, many different carbs, too much to try and guess on.

[Rich82GS750TZ]

Use this write-up found on BikeCliff's website to FULLY dismantle/dip/clean/re-assemble your CV carbs.

https://gsarchive.bwringer.com/mtsac/~cliff/storage/gs/Mikuni_BS-CV_Carburetor_Rebuild_Tutorial.pdf

If I were you, i would contact the author, member Nessism . He has compiled and sells complete sets of o-rings for the carbs.

Not sure where you'd find the missing springs.

And yes, if you don't know who/when your last valve clearance check was done, you need to do that too.

[Rich82GS750TZ]

Also. The model and specs for most GS carbs by bike year and model is on a chart here (I did not compile the data and cannot confirm accuracy of the data). This is also found on BikeCliffs website.

https://gsarchive.bwringer.com/bikecliff/images/carbspec_float_height.html

[rphillips]

Welcome Rusty, hoping, and thinking, you're gon'na be impressed with what you're gon'na learn around here. Looks like it's already started...Congrats on your purchase.

[rustyspoon]

Use this write-up found on BikeCliff's website to FULLY dismantle/dip/clean/re-assemble your CV carbs.

https://gsarchive.bwringer.com/mtsac/~cliff/storage/gs/Mikuni_BS-CV_Carburetor_Rebuild_Tutorial.pdf

If I were you, i would contact the author, member Nessism . He has compiled and sells complete sets of o-rings for the carbs.

Not sure where you'd find the missing springs.

And yes, if you don't know who/when your last valve clearance check was done, you need to do that too.

Thanks, this is exactly what I was looking for, I'm going to be much more confident going into the dip now!

Also. The model and specs for most GS carbs by bike year and model is on a chart here (I did not compile the data and cannot confirm accuracy of the data). This is also found on BikeCliffs website.

GS850 Carb Specs and Float Height Pix
https://gsarchive.bwringer.com/bikecliff/images/carbspec_float_height.html

This is also very helpful, and gives me at least a serial number to start my looking!

Welcome Rusty, hoping, and thinking, you're gon'na be impressed with what you're gon'na learn around here. Looks like it's already started...Congrats on your purchase.

Thanks @rphllips I've definitely been very impressed so far! I've been a part of a couple other bike forums that have a similar amount of information, but this is by far the easiest to navigate and find answers!

[rustyspoon]

I have questions to those who would know better than I, though it might be better to make a new thread in the Engine/Drivetrain/Clutch Forum...

What diameter shims do these tappets need? All the kits that I see are for a specified diameter and for the prices I'm seeing I'd really appreciate not having to buy multiple. The Service Manual gives parts numbers for replacement shims (That have changed since the manual was published - https://www.suzukipartshouse.com/oem...am-shaft-valve), but the Suzuki parts catalogue doesn't give any specifications other than the thicknesses between 2.15 and 3.10 mm. For example, https://www.suzukipartshouse.com/oem...-tappet-t-2-15

Also, as I go about the valve adjustment, how essential is the shim tool? it seems to me there there could be a number of substitutes for the tool, but I'm not sure what they might be...

[Suzukian]

You can make a shim tool. It pushes down on the side of the bucket to push it down, not touching the shim, this allows you, usually with a magnet, or needle nose pliers to remove the shim (shim over bucket). They're cheap enough to buy. This video shows the tool in place. The diameters for all shims in those years are the same. Not anything you can do about. They have kits on EBAY that have all the shim sizes. They don't cost that much. I have cam followers on my Suzuki, so I don't need shims.

[Rich82GS750TZ]

Or you could just use a zip tie. Look on BikeCliffs website link in my signature) for Valve Adjustments (8 valve) and Zip Tie Supplement. In the left column in the section below the Owners Manuals.

There’s been plenty written on the forum about the zip tie method. Use the search.

[Suzukian]

Never heard about the Zip Tie method. Would have checked it out if a link had been posted.

[Nessism]

There is no need to buy a shim kit. Measure clearance, remove the old shim and take inventory of thickness, then calculate what size you need. Z1 sells shims for something like $6 each.

[rustyspoon]

Or you could just use a zip tie. Look on BikeCliffs website link in my signature) for Valve Adjustments (8 valve) and Zip Tie Supplement. In the left column in the section below the Owners Manuals.

There’s been plenty written on the forum about the zip tie method. Use the search.

Thanks for letting me know, I didn't realize that BikeCliffs site had so many how-tos on it! The Zip Tie Supplement is very interesting but if that's the alternative I think I'll be okay to get the tappet depressor. I'm paranoid about damaging . . . really anything on my bike, so sticking something between a valve and it's seat to keep it in place makes me a little nervous. And I have been able to find a local shop that will sell me shims for 10 Canadian Rubles, 5 if I exchange. So I don't need to worry about the frankly ridiculous $300 price tag for a shim kit and now I'm more comfortable with the expense for the depressor tool.

The Valve Adjustments how-to was super useful, and for anyone looking for the same information I was the diameter for the valve shims is 29.5mm

[tom203]

This eBay seller claims to have the mixture screw setup

https://www.ebay.com/itm/292524107882?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=YRXifaZBQQ2&sssrc=2349624&ssuid=ARSR0K5ISZu&var=&widget_ver=artemis&media=COPY

you need these or bike will never behave! For the 650, I found the zip tie method the easiest.

[rustyspoon]

This eBay seller claims to have the mixture screw setup

https://www.ebay.com/itm/292524107882?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=YRXifaZBQQ2&sssrc=2349624&ss ui d=ARSR0K5ISZu&var=&widget_ver=artemis& media=COPY

you need these or bike will never behave! For the 650, I found the zip tie method the easiest.

Thanks so much for the listing! I was able to get replacement washers, o-rings and springs from a local shop, though the springs are taller than the stock ones. I believe they will work with some minor adjustments but in the case that they do not I will keep this listing in mind!

On an update, I adjusted my valves and the main issue has been fixed; the exhaust on cylinder one had no clearance and neither did either valves on cylinder 4. Went on a shakedown run to see if that had fixed my main issue, and everything ran super smooth! Though there was some valve noise from cylinder 4, but that's because I adjusted too far for safety's sake. I have some other issues that I've found, but those are mainly electrical and I haven't gone digging to see what they might be caused by yet, so I'll make a new thread in the electrical section if I have to.

That being said, while adjusting my valves I ran into something interesting, and not in a good way. That's for another thread though...