just had left side engine caseing changed now my blaster is back fireing and running bad

Are you talking about the case for the bottom end? Better leaktest!!
Eyup pal yeh the alyminium one and there is no leaks I thought maybe the stator is not in the right position could this be the cause
 
Unless stator is modded it can only go on one way. If it is modded you're still only be +4.

If all else checks out, check flywheel key.

Who did the work?
 
No matter what position the stator plate is in it should cause no problems unless the coils are rubbing against the flywheel?

What were the results of the leak test, how long did it hold 7 psi for?
 
Spluttering and bsck fireing had the plug out to check spark had a spark yesterday checked it again to day I have tried a new coil but still no spark could the coil have been on its way out yesterday because wen I got the engine back and fitted it sounded beatiful cut it out startec it again sounded mint went to start again and was backfireing when trying to start and wen it did start ran realy badly popping and farting hope this helps sorry about the story lol
 
The coil...... Also did you remove or mess with the fly wheel at all? Is the flywheel nice and tight? What is the reason you replaced this gasket for?
 
The coil...... Also did you remove or mess with the fly wheel at all? Is the flywheel nice and tight? What is the reason you replaced this gasket for?
I had the full side of the engine case the gearshaft side changed cause the chain come off and snapped the aluminium case and yeh the fly wheel has bin took of and the stator plate and could the timeing be out
 
Sorry to be a parrot, but what were the results of the leak test you did after re build.

I presume you did one!
I dont c how even if the case had the slightest leak it would let it start up 3 times and be running fine then come to start up again and have no spark and I will have it leak tested tomorrow one hundred percent just to make sure it isnt leaking after I have solved the problem of having a spark ten 20 minz later wen I got bacj from buying new plug because I thought this could be the problem then found out no spark I rekon if I could get it sparking again it would run mint
 
My concern that it was not leak tested was in your best interest.

I possibly has no relation to the spark problem, but if you fix the spark, start it and ride with an air leak, you will have a bigger problem!

Maybe you could have broken the HT wire where it goes into the plug boot.

Take the boot off by unscrewing it and cut off about 1/2" of the wire, then screw to boot back on.

There is a possibility that the Woodruff key has been sheared from multiple backfires, you may find that you need to lap the flywheel.