Hey guys, so I bought a soda blasting setup from harbor freight, I'm still trying to work out the kinks in operation. It all seems to be working, but my cabinet is the smaller version and once I start shooting soda it's like a blizzard in there and I can't see what I'm doing for crap.. If i do it outside, it gets all over everything and obviously can't be reused.. So I'm still figuring that out.
Anyway, I disassembled the swing arm to try and determine if something is missing causing the left and right wobble when connected to the frame, but it seems like all the parts were there.. I think I might have been missing a washer or two so hopefully that's all.
I have heard it's a good idea to replace the bushings with bronze ones, anybody have any luck with this or is it better to just replace the oem plastic ones? Oh yeah, the left one broke during removal.
Trying to finish getting my tank cleaned out as well, doing another couple rounds of electrolysis.
Also, I have two rear sprockets, the gold one was on my wheel, the other in boxes of parts. The casing attached to the black one is too large to fit the wheels I have, which I believe are gs wheels, but I'm not positive. The gold sprocket has 34 teeth and the black one has 40 teeth, which one should I use?? I like the black one better because of the holes, but want to have proper gearing. Front sprocket is 15 teeth.
Yes, you have a GS swingarm, wheels and center hub that attaches to the sprocket. The silver sprocket is shot, worn too much. On the gearing. I have a 42 on my 550 and I feel it's perfect. Initintially I had a 40 and it was geared too high in the lower rpms. Good thing about these rear sprockets. There is a wide variety to choose from as all the GT and GS models will work. You'll also like your GS wheels much better than having spokes. Spokes are an extreme pain in the ass to keep clean and the oem ones oxidize very quickly due to the zinc plating. But, I like the vintage look with spokes. I have a GS and contemplated putting them on one of my GT's. But, I like that original look to the wheels. The plastic bushings work fine. You have all the parts. But, one bushing had the end worn off and the torque for the swingarm bolt might have not been tight enough to squeeze the frame close enough to the swingarm. Causing slop. If you over torque that nut, it will make the plastic bushing wear too fast. You have to tighten it to factory recommendation torque.
Last edited by pearljam724 on Sat Jan 18, 2014 9:13 pm, edited 1 time in total.
pearljam724 wrote:Yes, you have a GS swingarm, wheels and center hub that attaches to the sprocket. The silver sprocket is shot, worn too much. On the gearing. Both of your sprocket tooth counts gearing are too high as well. I had to temporarily use a 42 from my 550 with a 15 tooth front. It pulls descent at that gearing, but I have been waiting to lace my 750 wheel and hub with new spokes. When that is finished, I'll use a 45 tooth rear sprocket. With a 15 tooth front sprocket. Any rear with a minimum of 43 to 47 teeth should be a happy low to mid range. Anything higher would be too much torque for my taste. Good thing about these rear sprockets. There is a wide variety to choose from as all the GT and GS models will work. You'll also like your GS wheels much better than having spokes. Spokes are an extreme pain in the ass to keep clean and the oem ones oxidize very quickly due to the zinc plating. But, I like the vintage look with spokes. I have a GS and contemplated putting them on one of my GT's. But, I like that original look to the wheels. The plastic bushing work fine. You may be missing dust cover end caps or the torque for the swingarm bolt is not tight enough to squeeze the frame close enough to the swingarm. Possibly, causing slop as well.
My swingarm is a from a GS as well? Ugh.. How can you tell? I guess it's not necessarily a bad thing, just surprised. That rear wheel seems rather small as well, I think its a 16.
I can tell because I own a GS. Disregard what I said originally about the gearing. I had to edit that, thinking you had a 750 for a second. Read what I edited. Yes, the rear wheel on a GS is 16 inches. Compared to the GT's had 18 inch rear wheels. You also have GS front forks. The bike will handle better with the GS front forks. But, I'm not sure if that's the case with the smaller rear wheel too being on a GT. My GS 450 handles extremely well for a bike of it's age. That's partially due to the fact that the late model GS front forks are filled with air. You can easily adjust the dampening on those forks to your liking. There is a air nipple to attach compressed air or a bicycle air pump to. It's located under the fork caps where they feed though the top triple tree. If you ever attempt to adjust that dampening with a compressor. DO NOT force a large amount of air at once or you will blow a seal. And DO NOT exceed 18 pds in either fork. 7 to 18 pds is all that is allowed. They both have to be exactly the same or the bike will not handle properly. I like mine at 9 pds.
Last edited by pearljam724 on Sat Jan 18, 2014 9:45 pm, edited 1 time in total.
Thanks for all that info pearljam, I think my swingarm is actually still from a GT however, it looks the same as all the others I've seen on eBay, whereas the GS swingarms tend to have an "X" stamped on the flat section just behind the pivot, this area seems to be longer for the GS's as well from the pictures I have seen, as opposed to the shorter stamped section on th GT's to accommodate the larger rear wheel. If you look at my last picture there is a large amount of room between the tire and swingarm pivot. I definately have GS wheels though. I'll have to look at the forks again, I assumed these as well were stock GT forks, but I'm still learning to differentiate all these bits.
More to come tomorrow.
No problem. You can tell the difference between the swingarms where the chain adjusters are. The GT's have much bolder inlays for the hash marks. The GS's are printed smaller. The GT's swingarms are more stout where the brace is that holds the axle. The GT brace is also solid all the way through that meets the axle portion. The GS swingarm brace is welded separately to that section. My GS swingarm and wheel has the same larger gap between it and the wheel. You definitely have a GS swingarm.
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Last edited by pearljam724 on Sat Jan 18, 2014 10:01 pm, edited 2 times in total.
I just fitted that same rear wheel or one like it to a GT750 in the stock GT swingarm which is identical to that one. Or at least it looks the same. I have a GS swingarm (no idea what size GS) that's around 2" longer than a GT arm and has an eye type bottom mount.
It's also about 3/4" wider at the wheel end and is for a disk brake.
Back to the side play. There should be shims in those end cups to take up all the end play so that the swingarm does not move side to side when tightened.
tz375 wrote:I just fitted that same rear wheel or one like it to a GT750 in the stock GT swingarm which is identical to that one. Or at least it looks the same. I have a GS swingarm (no idea what size GS) that's around 2" longer than a GT arm and has an eye type bottom mount.
It's also about 3/4" wider at the wheel end and is for a disk brake.
Back to the side play. There should be shims in those end cups to take up all the end play so that the swingarm does not move side to side when tightened.
Richard is correct. He calls it a shim. It's a washer/shim that is inserted under the dust/grease covers. You need those also. They will also prevent too much grease being squeezed out from around the cover as well. I remember how much of a pain it was to hold those washers/shims in place while feeding the axle through. It's very tight between the covers and the frame. While trying to hold them, the swingarm in place and feeding the axle through all at the same time. I used ordinary washers that were extremely close as the diameter of the axle. The closer you make that inside diameter of the washer. Less grease gets pushed out around the covers and less dirt is allowed inside the pivot. Part no. 11 The other washer part no. 7 goes on the outside of the frame. Under the nut.
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Last edited by pearljam724 on Sat Jan 18, 2014 10:59 pm, edited 2 times in total.
pearljam724 wrote: The plastic bushings work fine. You have all the parts. But, one bushing had the end worn off and the torque for the swingarm bolt might have not been tight enough to squeeze the frame close enough to the swingarm. Causing slop. If you over torque that nut, it will make the plastic bushing wear too fast. You have to tighten it to factory recommendation torque.
I can account for all the parts, the washer and o ring is pressed inside the end caps. That broken bushing was my doing, it looked just like the other one but I snapped the end off trying to remove it with a vice. Perhaps the swingarm wasn't tightened down all the way causing the play.
If you had the washers/shims under the covers. Than I agree. I can't recall the torque spec on the nut. But, it's has to be pretty tight to take out the slop. Even with new bushings and all the required parts. The required torque will squeeze the frame very minimal. That's all that's needed to take out the slop if you have good bushings and the shims installed. Just don't over due it or the bushings wear. I also think the nut will lose torque over the years. I would put a small amount of Loctite on the threads. Or add a lock washer instead of a flat on the outside of the frame. I hear a lot of comments on here about the plastic bushings wearing. Yes, they wear. But, that's due to incorrect torque. Too tight or not tight enough. It that's correct and stays that way, they should last forever. Has very little to do with them being made of plastic.
FYI, Stock wheels were 18" rear and 19" front. Only the 78 GS had an 18" rear whee and were spokesl. From 79 on (mags), they got smaller. Stock sprockets are 16 - 40, but with that tiny rear wheel you will need to drop that down some. Maybe the 36 is there for that reason. Not that it matters, but I have 2 GT550 swing arms doing nothing for a living. Both are in very good condition.
I was born with nothing and still have most of it left.
Coyote wrote:FYI, Stock wheels were 18" rear and 19" front. Only the 78 GS had an 18" rear whee and were spokesl. From 79 on (mags), they got smaller. Stock sprockets are 16 - 40, but with that tiny rear wheel you will need to drop that down some. Maybe the 36 is there for that reason. Not that it matters, but I have 2 GT550 swing arms doing nothing for a living. Both are in very good condition.
My concern with the rear wheel is that even with the stock 18 inch wheel these GT's have poor ground clearance, with the 16 that I have the bike sits very low and I feel as though when I do some cornering I will have to go very slow to prevent the pipes from scraping. I realize that this is an old bike and my expectations for handling shouldn't be all that much, but I would like to try and achieve the best result I can for this chassis. I'd like to at least get back to the 18 inch rear wheel so I could lean over just a tad more. I really like the look of these GS mags and I'm hoping to find a larger version. I have a lot to learn about handling, but the front will remain as is for now with the 19" GS mag and current forks (be them GT or GS I haven't determined yet), the rear will be subject to change depending on my first few rides.
Thanks guys.
Also, is this petcock screen replaceable? It is cracked on one side and ripped at the base, it doesn't seem to detach easily so I didn't want to yank to hard and risk ruining it if it can't be replaced.
Oh yeah, the left one broke during removal.
Ugh.. How can you tell? I guess it's not necessarily a bad thing, just surprised. That rear wheel seems rather small as well, I think its a 16. 
