I was wanting to know what kind of piston I should get for my blaster? I would like a lighter piston and if the stock compresion (correct me if im wrong)is 6:6.1 I would like to change it to 11.1 compresion. What name brand should I go with and what would be a good compresion ratio to change to? Please list any other mods for a blaster that are good.


Ryan Harris blaster yz490 750 banshee

 

Weisco ALL THE WAY!!!!!!!!

1998 Yamaha Blaster
W/ lots of mods

 

I am going to go with Weisco but I still need to find the type of piston I need. Do they make a piston that is allot lighter than stock and change the compression from 6.1 to 11.1 please help? All oppinions will be much appreciated

 

Look for an ad from Vito's in the Feb issue of dirtwheels. They sell a weisco piston for the blaster that boosts compression, is lighter and has larger intake window openings. It produces an advertised 5 hp gain in a stock motor. They don't say what rpm the gain is at (probably in the low - midrange).

You should NOT be looking for a piston with a specific compression number. The 6.6:1 ratio you mention is the uncorrected compression ratio and typically for two strokes, these numbers are very low. More importantly is the corrected compression ratio and static compression numbers, both of which require an engine specialist to set for your particular motor. Static compression is measured with a compression gauge and is around 130 psi on a stock blaster. The 11:1 ratio you're looking for would imply a corrected compression ratio suited to a motor running at least 100 octane fuel, BUT, there are other factors including head design which will dictate whether or not that will be a proper compression for your motor. Simply bumping the compression up to an arbitrary number is not going to give you what you are looking for.

If you really want to learn more about a blaster motor and a specific build up, go to www.macdizzy.com and get into the sand dune pages. There is a very detailed blaster motor build that will likely answer many of the questions you have.