Hello i have a 2001 blaster that is stock with no upgrades that has low compression 25lbs. my qustion is since i am going to replace the topend i am looking for opinions on what piston i should use or should i bore it out and what other upgrades i should do for more power. I will be tearing apart tomorrow to see if any damage was done to the cylinder. I do have a fmf slip on. All suggestions would be greatly appreciated thank you
Low compression
- Thread starter geo 00
- Start date
The inspection of the piston and bore will guide you to what to do.
With such low compression I would expect some damage or wear in the bore.
If you need a bore, fit a forged piston, not the cast variety.
Your builder will be able to tell you what size piston to order, if it has to be re-bored.
Your first thoughts on upgrade for power is to get an aftermarket pipe tyo suit you type of riding.
Post what and where you want to ride and someone will chime in and offer advice.
With such low compression I would expect some damage or wear in the bore.
If you need a bore, fit a forged piston, not the cast variety.
Your builder will be able to tell you what size piston to order, if it has to be re-bored.
Your first thoughts on upgrade for power is to get an aftermarket pipe tyo suit you type of riding.
Post what and where you want to ride and someone will chime in and offer advice.
forged piston wiscos on ebay are cheap and nice. a aftermarket exhaust system minor porting head milled and hemied. and the squish between piston and head tightined up. easy HORSEPOWER
the upgrades i mentioned are what ive found are the motors weakest links and most simple to start with. i am my own engine builder and ive experamented to find these results. Thats something you'll find 85% of the people dont do on here. lol some of the most experience people on this site dont even build there own engines. think plan when building, Presure of piston Lenghth of stroke Area of pison and Numbler of rpms. and btw over 75% of all horsepower you'll make is gonna be out of your topend.
Ok i got it apart today the top ring is broke and also the piston has a little chunk missing between the ring grooves and the bottom ring groove is smashed so i will need a topend thats fine my concern is where is the missing piece of ring. I checked in the cylinder ports not there shook the exhaust pipe not there looked down in the case best i could not there should i split the case a try to find it or would it have went out the exhaust before it quit running? Was going to take engine from frame and turn over but thought it would stick to the case because of the film of oil in the case.what would be the best thing to do? also the cylinder is fine no marks will just need honed.I am going to get a forged piston should i also get one with a higher compression ratio would it make any difference and if so do i need to jet it?
the bore should be checked thouroughly with good measuring tools, like an accurate bore gague and calipers. even though there are no major imperfections it may still be egg shaped and need bored to the next size, (or two) over. its hard to say how to be 110% certain the piece of piston is still not in there without splitting the cases. i would check it really well and mayube turn it upside down, rotate the crank and spray it out really good with brake clean, carb cleaner, ect. then maybe hit it with some compressed and run it./ but thats just my opinion and not a certain way to make sure there is nothing still in there. it could have even worked its way into the crank bearings. (worst case). they do not sell a high compression 2 stroke piston that i am aware of. you can increase compression by modifying the head if you wish. you will need to tune the carb with any mods that you do. a cheap way to get a good increase in HP is porting and head modifications and now is a great time to do just that. along with a good aftermarket pipe and a well tuned carb it will be a much more fun machine to ride!
all pistons should be around the same, i dont think there is high comp or low comp piston for blasters altho i could be wrong, it wouldent make sense anyway. you can use any piston and run it with high comp. just get a normal wisco piston and if you want high compression mill the head down some theres a ton of squish between the piston and the head on stock blasters. after this work you'll need to or should run 93 oct (surpreim fuel). cuz if not it may have spark knock and reg gas sucks now adays. youll deffinitly need to rejet for best performance
