250 over 490 in lowest terms is 25/49
3/7
490/756 = 35/54
42/490 in simplest form is 3/35.
The least common multiple of the numbers 70 and 98 is 490.
490 years
That would be a negative.The 490 which is probably a 1982 model as 1981 was a 465 were all side exhaust ports .The 82 yz 250 was a centre port with a twin tube frame. Also the expansion chamber on a 250 needs to be much larger than on a 490.You can get a new pipe from DG in usa or watch ebay. Good luck.
2/5
31/98
490 = 490
44 over 490
490
90% of 490 = 90% * 490 = 0.9 * 490 = 441