LaVern

That sounds like a real good idea. Thanks for that. I take it the metric 14mm or 16mm are the standard pipe tread sizes ? I have checked metric bolt sizes and found nothing to fit. I'll do what you suggest and post back on here my results. Thanks. LaVern

That looks like what I am looking for. Do you know specific model and year? LaVern

I'm going to try to download the pictures comparing the new vs. the OEM. The new is on the left and the OEM is on the right. This is looking at them from the backside. As you can hopefully see the outlet on the new one is lower than the OEM, and this is just enough to hit on the cable coming out of the carb top. That's why if a petcock had the exit to the right or the rear towards the rear wheel it would clear everything. I may have to further research metric threads. LaVern

b40rt, The leakage from the original petcock was out from the face of the petcock plus it is unable to shut off fuel to carb completely. No problem with fitting up to the tank itself. This has to do with the rubber disc that controls the off/on/ reserve positions of the petcock. The rubber washers on the new petcocks are not interchangeable. I may end up just using the new petcocks but I am hoping to get a petcock that allows the lever to face outward. Thus thread size needed. Thanks for your response. LaVern

I have a1975 RL250 I reconditioned several years ago. In the process I needed a new petcock due to leaking past the on/off position, plus leaking around the petcock on/off lever. I originally found a supposed OEM petcock from Partzilla I believe it was, and it worked but the location where the gas line connected sat lower than the original and since it exited out the back the line hits the throttle cable on the carb so a pretty extreme angle on the gas line is needed, so much so that it partially kinks the gas line. Since it is threaded, and the body of the petcock can be rotated, I had just turned it to miss the throttle cable. The trouble with that is it puts the lever facing forward making access somewhat difficult. So last year I got another petcock from Steven Pitt at Suzuki/Beamish Owners Club who I think has sold it to someone else now but that really doesn't matter. He said many people had used that petcock very successfully so I bought that. Well it is Identical to the OEM one I got previously. As I said, it will work but not as nice as I would like, and it is definitely different than the original that came on the bike. I am the original and only owner and have never had it replaced until several years ago. Any way that was along way to get to this point. Does anybody know the thread size on a 1975 RL250? A petcock that would have the line exiting to the rear, towards the rear tire, instead of towards the carb would be perfect. I see quite a few on line that look to have the same method of threading on the tank. I just need to know the thread size to be sure they are the same. I am unfamiliar with metric pipe threads, and I have tried to match up a metric bolt thread with no luck. Thanks for reading and any information is greatly appreciated. I probably should have taken a picture of the original vs. the newly purchased one for comparison. I will try to get to it tomorrow. LaVern

Feetupfun, Thanks for that information. I have posted this same questions on the TY Yamaha forum, which I believe is out of France, and I have been corrected as to my thoughts about what coil was the source (ignition) and what is the lighting. It seems from all the info I got from them that the damaged coil is actually one of two lighting coils, and what is confusing to me is the left side stacked coils has the ignition on the bottom ant the top is the second lighting coil. If that is the case, I don't need to do anything with the damaged coils because the bike has no lighting circuit on it. I know that when my son bought it there were no lights, and no sign of ever having any lights or brake switches etc. When talking with the folks on the other forum I got the impression that perhaps Yamaha had lights on all of the TY250s. I'll have to talk to my son about what he wants me to do. I've already bought new points and a condenser so getting the original magneto vs. a CDI unit would be less cost. I still have a while before I get to that part of the restore. Thanks again. LaVern

Actually more accurately, a small town in northwestern Pennsylvania, called North East. LaVern

In the U.S. in the northwest corner of Pennsylvania. LaVern

Hello All, Its been almost 2 months since I last posted about the 1977 TY250D 493 series that trying I am restoring for my son. Well in the process of replacing the points and condenser I managed to scrape the source coil pretty bad. Apparently the tool to keep the flywheel from turning stuck through too much at one point. I'll post some pictures. Looking at all options I think rewinding the coil would be the most cost effective. But to do that I need the resistance specs on the coil. I have a service manual but it is the European version and it doesn't have any info on an American version. Anyway, the specs I have give 2 different required resistance, one for 9 European countries and that spec is 1.6 ohms. and the specs for the English model is 0.1 ohms. Can anybody give me the specs for a 493 series sold for America? I already have the points and condenser purchased so I should probably try to use the magneto ignition vs. a CDI though the CDI seems to be less maintenance and more reliable. Thanks. LaVern

Feetupfun, Yes I do remember my SL125 and XL175 having tool sets. I guess the opening seems small. As I think of it, pretty interesting engineering, utilizing every cubic inch of space. Thanks for responding. LaVern

Okay. Did they come with a set of tools or was this just a "place" to put some? Thanks for your reply. LaVern

Hi All, I'm getting going on the restoration of the TY250. I got the frame all stripped down except thw triple clamps and the foot pegs. During the process I came across a small area behind the headstock that has a hinged cover which opens from below. It is held closed by a knurled thumbscrew. A bunch of hazel nuts and looks like flower seeds fell out when I open it. What is it for? I'll tr to post some pictures.

Thanks for your input. As you, I think if my son rides it after restoration, it too will not be in competition, but as a trail bike. So perhaps in reality, it isn't a big deal for what it would be used for. I guess I should pick his brain about the level of this "restoration" that he wants. I just go back to the conversation I had with him when he stated with no doubt what so ever that the original flywheel made the bike easier to ride. I now have two other vintage trialers, a 1975 Suzuki RL250, and a 1975 Honda TL250, neither gets ridden in any form of competition, just trail riding. I suspect that will be the role of this bike also. LaVern

That is a possibility. Next question, Why would somebody who competes in trials, want a lighter flywheel? I always thought that the heavier wheel allowed the engine to be run on lower RPMs, especially when coming out of a high RPM situation where increased RPMs would lose traction easier? Of course my understanding could be completely wrong and if so, I welcome a lesson on Vintage Trials practices. I am 71 years old and most of what I know, (and it isn't that much), was acquired in the mid '70s when I first learned about the sport. I never competed and I will admit that most of my understanding of this aspect was from the fact that some of the manufacturers were using standard engines with larger flywheels on their trials models. Also if I remember correctly, replacement with a larger flywheel was a common after market modification at the time. Thanks. LaVern

Well I definitely don't have the one that it came with. The one I have is 25.9mm wide and 4.4mm thick. Substantially smaller, thus lighter. Well thank you everyone who read and answered my post. Now I wonder if I might be able to find one of the original sies. LaVern

Thank you! This will help me figure out just what I have. FIrst thing tomorrow I will check it out, and for anyone interested I will post th dimensions. Thanks again. LaVern

Seems I overlooked this posting. If the dimensions are available they surely would be helpful. The pictures look good. Thanks. LaVern

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

And another one. LaVern

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

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

Italic Keyboard shortcut Ctrl+I 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

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

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

timdog and Old Gezzer, thanks a bunch. My son wants to do a restore on the Yamaha. We'll have to see how that goes. LaVern