It should be an 12N 12A-4A battery
According to WikiAnswers, the proper battery for a Maxim 400 (the Seca's sister) is 12N 12A-4A. I'm looking for one also. This is the same battery I used in my '72 Yamaha XS650 although it had a "-1" designation at the end.
try the yamaha seca store.
Try one off of a yamaha seca 400
The battery on a 1997 Yamaha Seca II is located under the seat. To access it, you can remove the seat by unscrewing the mounting bolts or using the latch mechanism, depending on the model. Once the seat is removed, you will see the battery housed in a compartment beneath it. Make sure to disconnect the negative terminal first when servicing the battery.
If there is one it will be located from the main fuel line running from the petcock to the carbs.
it's behind the right suspension bar. it's a black allen tip.
ebay
Yes, a round headlight will fit on a Yamaha Seca. Just be sure that the model and specifications match what will fit into the mounting brackets.
81hp
2
The spark plug gap in a Yamaha Seca is 1/2. It can be easily obtained and is very affordable and likely to be replaced by the owner. It is a quick replacement.
There is NO WAY a stock Seca 2 will do 140. About 115-120, which isn't bad.