back firing and hard start

[jakerman02970]

hi there

1993 blaster is now back firing like crazy. And it is hard starting. i took the carb off and cleaned and replaced most of the parts that came in the rebuild kit off ebay.

1 Why is it back firing and blowing stuff out the tail pipe?
2 Why wont it stay running on idle?

i adjusted the air mixture exactly 1.5 turns out from botton out.

any suggestions from the blaster experts Thx James

 

[yb200]

check your reeds...then check your flywheel key

 

[jakerman02970]

the blaster ran over the summer then the kid let it sit for like five months. i changed the fuel and such. Can the reeds just go bad and can you give me more info on the flywheel key? i appreciate it james

 

[yb200]

the reeds may have a crack or chip in them or one may be broke off.....the flywheel key hold the flywheel on the crank and if the key gets sheared it will make the timing way off causeing it to run like sh*t.

 

[rideyamaha09]

Check the ground wire at the ignition coil under the seat, if its not getting a good connection it'll cause backfiring. I'd also agree to check the reeds and flywheel key.

 

[jakerman02970]

awesome info but how do you go about checking the flywheel key?

an another question on the carb... on the opposite side of the starter plunger (right side sitting on machine) there is a big hole with what looks like threads in it. Is there supposed to be a screw or needle of some sort in there? it almost looks like a idle adjuster on four strokes carbs. thanx james

 

[rideyamaha09]

To check the flywheel key you gotta remove the stator cover and I am pretty sure someone said you can shine a flashlight past the flywheel to check it and make sure it is in place and not sheared.

The spot on the carb, if you mean the same side of the carb as the choke is on, is where an idle screw would go, but its not drilled open since the idle screw is on top the carb.

 

[yb200]

you need to take the nut off the flywheel and you can see if its sheared...if so you need a flywheel puller

and that hole on the carb is for nothing