Blaster running bad

Jul 13, 2011
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A friend of mine brought me a 04 blaster in a non running state. He blew it up out of state. He had it bored and put a new piston in it. The first thing I checked was compression. It had 130psi cranking pressure. I checked the spark, thats strong. I pulled the air cleaner box and there was a puddle of gas in the box and the element is junk. I shot a little starting fluid in it and it fired and died. I pulled the tank off for ease of access. I pulled the carb out and pulled that apart. It looked clean inside. The idle air mixture screw was tightened all the way down. I pulled it out and blew air through that and the other circuits. I set the screw at 2.5 turns out. Put the tank back on and kicked it over. I fired up but it won't idle and the idle screw feels maxed out. It is real slow to accelerate. It sounds boggy and has slow acceleration. It sounds terrible. I am kinda stumped on where to go next. Is the cdi a possible culprit? Any help would be appreciated.
 
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I also noticed that the parking brake wire is snipped off at the handle. Does this wire need to be a closed or open loop to the cdi? I would assume an open.
 
Yup sounds like a reed problem.

While you have them off take a look to see if the piston is not in backwards.
 
Pulled the carb and visually checked them and also with my finger. They are intacted and working properly. The tors box is removed so that possibility is eliminated. I started it back up again and you can hold the throttle wide open and it sounds like its not getting past 4k rpm. I'm starting to think cdi. Its too bad the 04-06 ones are different then the older style. I have a older style sitting on my bench.
 
Pulled the carb and visually checked them and also with my finger. They are intacted and working properly. The tors box is removed so that possibility is eliminated. I started it back up again and you can hold the throttle wide open and it sounds like its not getting past 4k rpm. I'm starting to think cdi. Its too bad the 04-06 ones are different then the older style. I have a older style sitting on my bench.


the tors is inside the cdi box on 03+ blasters, it is not missing.
follow the link i posted above for 03+ tors removal, there are 2 wires that must be cut and connected at the cdi/tors box
 
Just learned something new. I didn't realize that the tors was integrated into the cdi. The connectors are just unplugged. I need to loop them to fool the cdi.
 
I decided to pull the reed cage and sure enough, piston in backwards. Pulled the head and cylinder and the piston looks ok. Just a nick by the exhuast port. I'm going to port the exhuast port out to get rid of the nick and I'll port the intake and add boysen ports too. I'm trying to read the main jet size and it looks like 230. Is that the correct size for stock carb? I would imagine I will go up 2 or 3 main jet sizes with the porting.
 
I decided to pull the reed cage and sure enough, piston in backwards. Pulled the head and cylinder and the piston looks ok. Just a nick by the exhuast port. I'm going to port the exhuast port out to get rid of the nick and I'll port the intake and add boysen ports too. I'm trying to read the main jet size and it looks like 230. Is that the correct size for stock carb? I would imagine I will go up 2 or 3 main jet sizes with the porting.

good save :)
yes, 230 is stock main jet
 
I also had the same problem as you do on a 01, tors was off and i was really pissed. Turned out the cylinder was cracked where the exhaust went in.
 
I decided to pull the reed cage and sure enough, piston in backwards. Pulled the head and cylinder and the piston looks ok. Just a nick by the exhuast port. I'm going to port the exhuast port out to get rid of the nick and I'll port the intake and add boysen ports too. I'm trying to read the main jet size and it looks like 230. Is that the correct size for stock carb? I would imagine I will go up 2 or 3 main jet sizes with the porting.
O ok good to hear.
 
Awk, how big of main jet would you think I would need to go to match the porting? The rest of the bike is bone stock.
 
Awk, how big of main jet would you think I would need to go to match the porting? The rest of the bike is bone stock.


usually only mods that effect the volume of airflow into and out of the engine require jetting changes.... airfilter, airbox, lid off, aftermarket pipes.

without those, making that same volume of air flow more efficiently inside the engine shouldn't have an effect,
but should be plug chopped to confirm