A bit of help please

Sparrow89

Member
Dec 24, 2011
208
6
70
LaHarpe Illinois
k so recently pulled apart my blaster engine because it wasn't running found a scored piston but cylinder is still good checked and double checked...just not sure what size the piston is the previous owner said it was bored over 40 but i have no idea for sure the piston i took out has A37K9 on the top and in center STD and below the STD is 573P8 if someone could please help me out here what size piston is this? I'm looking at buying a Wiseco piston kit but not sure which size i need to get. Also any thoughts on AmsOil 2 stroke Interceptor oil?
 
if you have gone this far , it would be best to have the cylinder mic'd and that will tell you what size piston you will need. Odds are it will need to be cleaned up with a hone or possibly bored out .
Some people like amsoil interceptor , BUT I ONLY run Maxima Super M Synthetic 2 stroke premix oil . for the Blaster the optimum mix is 32:1 , In my Banshee I run 40:1 .
Save yourself some headaches , have it bored out and a new matched piston kit .
you'll be back on the trails in no time .
 
k thanks and any ideas on estimated cost typically to have it honed and or bored? sorry for a 21 question deal still learnin on these 2 strokes and everyone is close till monday
 
theres several builders on this site , Ken Occonnor does great work . I actually send my cylinders to summit racing in stark Florida and have them do the work . Fast and very accurate work . my blaster top end was under 200 that included all work and piston kit .
 
There is a place on ebay that you send your cylinder, they bore it to the next size and send it back with a new piston, about $150. Don't know if they will just hone it. Never used them but it's something to go by. They are in Starke, FL.
 
boring the cylinder to it's max is a waste of good bores and provides very very little added performance
 
When i had to bore out my 03 blaster i took it to Carquest a local car parts store and they bored it for 70 dollars then i ahad to buy a piston kit but you wouldnt have to hassle with shipping or anything. check around at the local car parts or repair places. the yamaha dealer would be the LAST place i would go. my dealer gets about 75 dollars an hour for labor alone.
 
kk thanks...ya ill never be taking my blaster back to the yamaha dealer here again when in for a clutch shaft got it back no nut on the kickstart 2 nuts missing on top end and the remaining 4 where loose
 
the cost of shipping this cylinder to one of our builders on here is priceless to know it's done correctly, and a pro will tell you what piston to buy, and bore your cylinder to that exact pistons size when it's in his hands,
not bore first then purchase a piston
thats like playing russian roulette !!!!
 
Awk is 100% correct. Do to manufacturing tolerances a good machineist would measure the piston and bore to fit. More than likely a dealer would just send it to a shop and make $$ on top of what same shop would charge you. Nothing wrong with going local IF they ensure it's done right. If you do local make sure port openings are champhered, even if you have to do it your self.
 
k so i found a good guy locally who does boring and have heard great things bout him he actually bored all 13 of a friends 426 hemi's and hasnt had any issues with them...but should i wait till my piston comes in to take it in to him or should i wait...i ordered a Wiseco 68.25mm
 
no goin with 68.25 cus the previous owner had it bored to 68 and there is a little wear but not much and either way the machine work is going to cost the same and same with piston a wiseco 68mm sells for 124 as well as the 68.25 so figured eh might as well go for it i...ya i think the charts said the output of the 68.25 is 208.5cc as compared to 207 from the 68 not much and i think 195cc. if im wrong please say so im not 100% sure on those i just think thats wat i remember seeing.
 
ok an also i liked some opinions on stuff. (i know everyone has diff. thoughts but just some refs.) k so im not sure what reeds r in the intake but i know they are carbon fiber(good?? bad??) ive seen them alot on the net and they sounds good but ya...and also it has a Mikuni Carb on it not sure on size ill measure it today and post it tonight. and im wanting to get some new tires and rims i have nice ones on it now but wanna get some cheap rims on it for winter and some more aggressive tires than the RAZR's they are great but i cant get nothing for traction in snow any suggestions on the type of tire? and the last thing is exhaust it has a Graydon Pro line exhaust on it. as you can tell im new with the 2 strokes im a good mechanic and all just this is my first atv ever and finally decided i wanted a toy( dont we all).
 
Keep the Graydon Proline exhaust! Good pipe to have on a Blaster engine.

If you have your cylinder bored locally, that's fine if the guy knows what he is doing. HOWEVER, as others have said, you MUST BE SURE that the ports in the cylinder are chamfered prior to putting things back together again. If you don't chamfer the ports, a piston ring will get caught and the results aren't pretty. I'm making a big deal out of this because lots of mechanics who excel at working with car/truck engines don't know the proper way to re-bore a 2-stroke cylinder. Just a warning.

Run the AMSOIL, and mix it 50:1, just like it says on the bottle! I've had the Interceptor oil in my Blaster's system for months and it runs extremely well with it. Also, an engine running Interceptor oil won't smoke after it warms up. Result? Little to no "Spooge" around the exhaust flange. Great oil. I've given my Blaster Hell and it has never let me down running hard on AMSOIL. My .02.