toadson Posted June 16, 2009 Report Share Posted June 16, 2009 Hey everyone, my dad owns a 74-76 (not sure of the year, blue and white paint) Yamaha TY250 an the sprockets are pretty shot. I've tried looking online for new ones that use the 428 chain, and haven't come up with anything. I did see a European site that stocks sprockets, but uses 520 chain. We recently had to put a new chain on the bike, but had to use a 420 and not a 428, which may or may no be a problem if I order the stock size sprockets. Basically, I was wondering if it would be better to order 520 sprockets and chain instead of using the 420 chain and looking for 428 sprockets. They seem to be hard to find, and since we only use this dirtbike to peddle around on the farm, we'd rather not spend a bunch of money on it. Is there a site I'm missing to order the stock size sprockets? It looks like the part from Yamaha was expensive but is no longer available. Thanks for any help! Quote Link to comment Share on other sites More sharing options...
feetupfun Posted June 16, 2009 Report Share Posted June 16, 2009 Yes OEM Yamaha rears are no longer available from Yamaha. Yes you can get aftermarket 428 chain rears and fronts. What makes you think they will be cheaper than 520 sprockets? 428 and 520 sprockets from: www.bjracing.com www.tytrials.co.uk Quote Link to comment Share on other sites More sharing options...
toadson Posted June 16, 2009 Author Report Share Posted June 16, 2009 I just meant it would be cheaper to buy the 428's since we have a chain that should already work. Thanks for the links! Quote Link to comment Share on other sites More sharing options...
alan_nc Posted June 16, 2009 Report Share Posted June 16, 2009 There is a fellow on U.S. ebay that stocks a whole line of JT or Sunstar sprockets. Just bought a 428 x 12 for about $12.00 including shipping. You need to check the different inside diameters (there will be at least 2) and tell the guy what they are. Usually Honda/Suzuki/Yamaha/Kaw sprockets are all the same. The one I bought is listed for a Suzuki. Look at the sprockets and just email the guy. I have two '74 TY250's, one has 520 chain and the other 428. I really don't notice any difference. No matter which size you go with replace the chain with the correct one when you do it. Chain is going to run about $15.00 (from any local motorcycle dealer). Alan Quote Link to comment Share on other sites More sharing options...
toadson Posted June 17, 2009 Author Report Share Posted June 17, 2009 I'll have to look for him, any chance you could get me his email or ebay username? I'd appreciate it if you could. Quote Link to comment Share on other sites More sharing options...
ducman Posted June 17, 2009 Report Share Posted June 17, 2009 We have a dealer over here in germany and he makes alloy 428's rear sprocket,all my Ty#s have now thes procketes,exact replica of the original but in alloy.The front ones with 12 you can get directley from your Yamaha dealer. Chrs:mike Quote Link to comment Share on other sites More sharing options...
feetupfun Posted June 17, 2009 Report Share Posted June 17, 2009 We have a dealer over here in germany and he makes alloy 428's rear sprocket,all my Ty#s have now thes procketes,exact replica of the original but in alloy. The originals are alloy Quote Link to comment Share on other sites More sharing options...
alan_nc Posted June 17, 2009 Report Share Posted June 17, 2009 Here is the guy from U.S. Ebay: I was slightly off on the price. Patrick Lytle info@lytleracinggroup.com Qty Item ID Description Unit Price Amount 1 JTF1263.12T JTF1263.12T 8.99 8.99 Subtotal: $8.99 Shipping: 5.98 Currency is in U.S. Dollars (USD) Total: $14.97 USD Alan Quote Link to comment Share on other sites More sharing options...
ducman Posted June 17, 2009 Report Share Posted June 17, 2009 Last month i bought a original from a guy in france and it was steel. Chrs:Mike Quote Link to comment Share on other sites More sharing options...
toadson Posted June 18, 2009 Author Report Share Posted June 18, 2009 I sent Patrick an email and will hopefully get some pricing on the sprockets. Thanks a lot for the info, it was very helpful! Now if I could only find a new brake lever mount, as mine is busted where the cable adjuster goes. The only brake we can use is the rear, and it isn't the greatest for stopping. Quote Link to comment Share on other sites More sharing options...
fergie Posted March 15, 2010 Report Share Posted March 15, 2010 (edited) I have done a 520 conversion on a couple of ty 250's. Its the way to go for sure. The stock rear sprockets are dished and the aftermarket 520 rear sprockets are flat so if you go the 520 route you need to make a spacer out of your old rear sprocket. cut out the center of your old rear and machine the thickness down to the difference between the off set of the stocker and the new rear. install the new spacer to make the new 520 rear the same distance from your rear hub as the stocker. I think b&j racing sells the spacer and chain/sprockets you need . Edited March 16, 2010 by fergie Quote Link to comment Share on other sites More sharing options...
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