LaVern Posted November 8, 2022 Report Share Posted November 8, 2022 (edited) Hello Everyone, I just posted my intro a few days ago, and in part of that intro I showed my current project, my son's TY250. My question regards the flywheel on the TYs. This TY is a 493-200127, which makes it a 1977 vintage. Were the flywheels made extra heavy for them, and are they distinguishable from other 250 Yamahas of that time frame? I ask this because somewhere around 1992 or 93 my son bought this bike. He rode it for a while until one day it quit on him, no spark. My brother-in-law and I came to the conclusion that it was a problem with the points an no matter what we tried, could not remove the flywheel. I recall we messed up a wheel puller in the process. We ended up cutting the flywheel off. We acquired another flywheel from a 250 Yamaha at a motorcycle recycle yard. The owner of the yard said it was from a TY because it had the added ring for weight on the flywheel. It ran great for a few years until my son decided he wanted to ride Harley's, choppers and such and he parked the TY. Now I have it and I am in the process of restoring it for him. He tells me that he recalls the replacement flywheel was not the same as the original we cut off. I don't remember but I'm taking his word for it. So my question is, how can one know whether it is the right one? Obviously it worked for a few years until he parked it, so the question, is it the right one? I am laid up for a few days now from some minor surgery, so I know I won't be able to pull it off, but perhaps I can get a picture of it still on the engine. I did find the PT. # of the correct one from several different Yamaha OEM parts sites, #493-81350-11-00. They all had the same number but I haven't been able to find a number on the flywheel that looks like that. The pictures they show certainly do look like the right one with the added ring bolted on the outside, but my son says he remembers specifically that it did not run the same on low end. Anyway, in a few days I'll try to get if off or at least get pictures and dimensions. I'll try to put a picture up from Yamaha OEM. It shows the same type of ring bolted on as the one I have. Thanks for looking. LaVern Edited November 8, 2022 by LaVern Quote Link to comment Share on other sites More sharing options...
b40rt Posted November 8, 2022 Report Share Posted November 8, 2022 TY350 ? Quote Link to comment Share on other sites More sharing options...
LaVern Posted November 8, 2022 Author Report Share Posted November 8, 2022 b40rt, TY350? Did I miss type in the above post? The surgery I had was for cataracts, vision is still a bit blurry, so maybe I did, though I did not see where. If I did, I meant TY250 If not explain please. Thanks LaVern Quote Link to comment Share on other sites More sharing options...
feetupfun Posted November 8, 2022 Report Share Posted November 8, 2022 (edited) The TY250A flywheel has a smaller steel band on it than the TY250B, C, D and E models, but is otherwise the same as the BCDE flywheel. I can do photos if you need. Yours is a D model bike The part number for the TY250A flywheel is 434-81350-10 Edited November 8, 2022 by feetupfun Quote Link to comment Share on other sites More sharing options...
b40rt Posted November 8, 2022 Report Share Posted November 8, 2022 4 hours ago, LaVern said: b40rt, TY350? Did I miss type in the above post? The surgery I had was for cataracts, vision is still a bit blurry, so maybe I did, though I did not see where. If I did, I meant TY250 If not explain please. Thanks LaVern Maybe the flywheel you have is from a TY350 ?? Quote Link to comment Share on other sites More sharing options...
LaVern Posted November 8, 2022 Author Report Share Posted November 8, 2022 Italic Keyboard shortcut Ctrl+I 1 hour ago, b40rt said: Maybe the flywheel you have is from a TY350 ?? I think the flywheel from the TY350 looks completely different according to the views from Yamaha OEM. feetupfun, Do you know if that number is stamped on the flywheel someplace? I haven't been able to see it yet. Perhaps when I get back out in the garage and get it off I can take a close look. Thanks Everyone. LaVern Quote Link to comment Share on other sites More sharing options...
LaVern Posted November 24, 2022 Author Report Share Posted November 24, 2022 On 11/8/2022 at 2:27 AM, feetupfun said: The TY250A flywheel has a smaller steel band on it than the TY250B, C, D and E models, but is otherwise the same as the BCDE flywheel. I can do photos if you need. Yours is a D model bike The part number for the TY250A flywheel is 434-81350-10 Is there someplace that I might get the actual dimensions and perhaps even the weight? The one I have is 138.86mm, or 5.467" in diameter. I don't have an accurate scale to check the weight. I guess it really doesn't matter. It seems that as long as it works, it will do. It's just that my son has asked if it is possible to get the original, so I'm trying to verify what is the original. I am having problems getting the pictures from my phone to my computer so I can upload them here. I'll have to try later to down load them again. Thanks. LaVern Quote Link to comment Share on other sites More sharing options...
LaVern Posted November 25, 2022 Author Report Share Posted November 25, 2022 Well after returning from our Thanksgiving celebration, my pictures had arrived from my phone to my laptop. I will post them with to see if any one knows by the diameter if not by looking at it, if it is the correct one for my 493 series TY250. I think the number on the outside face of the flywheel is F143-3073. I am not sure what that means or refers to. I have found nothing in my research mentioning those numbers. LaVern Quote Link to comment Share on other sites More sharing options...
LaVern Posted November 25, 2022 Author Report Share Posted November 25, 2022 And another one. LaVern Quote Link to comment Share on other sites More sharing options...
feetupfun Posted November 25, 2022 Report Share Posted November 25, 2022 5 hours ago, LaVern said: Well after returning from our Thanksgiving celebration, my pictures had arrived from my phone to my laptop. I will post them with to see if any one knows by the diameter if not by looking at it, if it is the correct one for my 493 series TY250. I think the number on the outside face of the flywheel is F143-3073. I am not sure what that means or refers to. I have found nothing in my research mentioning those numbers. LaVern It's not the original type of flywheel for a TY250D but it will work fine. As expected, it's a TY250A flywheel. Do you still want dimensions or photos of a TY250D flywheel? 1 Quote Link to comment Share on other sites More sharing options...
feetupfun Posted November 25, 2022 Report Share Posted November 25, 2022 I came across suitable photos tonight so here they are. The flywheel on the left is TY250A. The flywheel on the right is TY250 BCDE Quote Link to comment Share on other sites More sharing options...
LaVern Posted November 25, 2022 Author Report Share Posted November 25, 2022 Okay, I can clearly see the Flywheel on the right has a thicker ring on the outside and I can't say for sure but it looks like mine has a thinner outside ring. I guess without weight and O.D. dimensions I have to assume that the flywheel I have is from a TY250A. It'll still work, but my son says he remembers that the bike was easier to ride with the original fly wheel. Thanks for the pictures. Now I guess I'll go with it. Perhaps I should ask, does anyone know of a source for the heavier wheel? LaVern Quote Link to comment Share on other sites More sharing options...
LaVern Posted November 25, 2022 Author Report Share Posted November 25, 2022 5 hours ago, feetupfun said: It's not the original type of flywheel for a TY250D but it will work fine. As expected, it's a TY250A flywheel. Do you still want dimensions or photos of a TY250D flywheel? Seems I overlooked this posting. If the dimensions are available they surely would be helpful. The pictures look good. Thanks. LaVern Quote Link to comment Share on other sites More sharing options...
feetupfun Posted November 25, 2022 Report Share Posted November 25, 2022 9 hours ago, LaVern said: Okay, I can clearly see the Flywheel on the right has a thicker ring on the outside and I can't say for sure but it looks like mine has a thinner outside ring. I guess without weight and O.D. dimensions I have to assume that the flywheel I have is from a TY250A. It'll still work, but my son says he remembers that the bike was easier to ride with the original fly wheel. Thanks for the pictures. Now I guess I'll go with it. Perhaps I should ask, does anyone know of a source for the heavier wheel? LaVern I've seen them advertised on US eBay at times Quote Link to comment Share on other sites More sharing options...
feetupfun Posted November 25, 2022 Report Share Posted November 25, 2022 The steel ring on the BCDE flywheel is 27.65 mm wide and 8.6 mm thick. Other dimensions are the same as the A model flywheel 1 Quote Link to comment Share on other sites More sharing options...
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