has any one had the same problem as me and my friend we both bored our blasters 20 over with wiseco piston and rings and we both blew base gaskets is this because of the boring of the cyclinder and the after market piston or is this just a fluke

 

Did you use a torque wrench to tighten the head bolts down ??

 

I have had the same problem with my base gasket blowing. Luckly I have a cousin that will do the work for me so I don't have to pay a dealership fify bucks an hour to change my gasket.

 

from the macdizzy site:

The Question - I was riding my 1998 blaster on ice a few weeks ago. I guess I was reving it high in 3rd gear. The base gasket blew, the piston and rings burnt up and it scored the cylinder. It cost about $150 to get the cylinder bored and for new piston, rings and gaskets. That did not include the labor, I did that myself. So I'd say yes 2-strokes are not meant to be ran with high rpm's and from what I hear they are more of a race bike. So from experience, put your bike up for sell if you like to ride in mud, on ice or run it the least bit hard.
The Response - If you blew out the base gasket on that Blaster I doubt it was because you were revving it too high, more than likely it was because no one performed a leak down test on the motor before you went racing. You may have noticed a air leak in the motor with a leak down test before that ever happened.

The Blaster motor has a short stroke and therefor makes it able to rev very high without fear of failure due to over-rev. As high as a Banshee (9000 to 10000 not impossible). Though it's air cooled it'll still turn those kind if revs. Usually the pipe, ignition or porting will shut down any rpm increase before the motor is actually over-revved.

A two stroke motor will rev WAY higher than a 4 stroke, and more reliably at those revs. For a 4 stroke to even come close to the power output of the same displacement 2 stroke it has to turn in (almost) as many power pulses. Try turning a 4 stroke 22,000 RPM. Very few are made that way (I'm thinking Honda NR500 mid 1980's). Remember the motorcycle Freddie Spencer was riding in the 500 GP's during those (crummy for Honda) years? It revved so high it even sounded like a 2 stroke.

Rick

 

I always make it a point to not only re-torque the head nuts after warm-up and intial run. But I also make sure that I re-torque all the other nuts/bolts too as well. After several cycles of heating and cooling everything kind of "settles" in and will need retorqued. With a matched cylinder and case(ported motors) it's especially important to re-torque, there's less gasket mating surface and it's crucial to do.

I would also reccommend that you use some sort of fuel/oil resistant adhesive. The best product that I use is stuff called Permatex Hi-Tack. It's aerosol and sprays on easily. Ensure that the pieces are flat(see macdizzy's site about "lapping"), and then absolutely clean, then coat the gaskets and re-assemble. Also ensure that the threads of the studs and nuts are in good shape, and that the dowel pins are lubricated lightly with anti-seize type compound so that it reached maximum clamp up without interference from the fasteners.

Good luck.

 

just last weekend I was riding with a friend who bought a 96 Blaster in January. It had a wiseco piston and a thicker gasket that another friend of mine had put in before he sold it. I know he didn't use a torque wrench because he never does. Anyway the new kid that bought it lost several nuts and bolts and didn't care for it. After about 20 min. of trails and 15min. sand riding it dies I have to get a tow roap to pull start it. We get it started and he pins it and doesn't let off till it dies again. we never get it started again. no compresion! There was no gaket on the left side and oil all over the place. We think it was from the crank case. It's at the dealer right now. it was real hot.