blaster keeps running with everything off including the spark plug wire

[JoeymackR12x]

i have 93 blaster. it takes a little bit of effort to get it started. Once it is started it runs really rough and if you ride it, then pull in the clutch or put it in nuetral it stays at a really high rpm. I thought the throttle was sticking, but then i checked and that was fine. It did it again and i pulled the spark plug wire off the spark plug and it was still running at a high rpm! Can i get a little bit of help, i am trying to fix this to give to my younger brother for christmas. I cleaned the carbs and jets, adjusted the setting on the carb to what my other blaster is set at. i cant seem to figure out, why it is hard to start, why it bogs down and runs rough, and why it stays up in a high RPM. Any help would be great!
Thanks
Joe mac

 

[blasterfreek30]

sounds like u have a bad airleak which is causing the cylinder to heat up so high that it will continue to fire even when the kill switch is hit or plug is pulled

 

[Paulie B]

^^Agreed^^
If it just happened then most likely it's a blown crank seal on the left side or if the exhaust is real smoky the right side.

 

[Braaaptor]

sounds like u have a bad airleak which is causing the cylinder to heat up so high that it will continue to fire even when the kill switch is hit or plug is pulled

^^Agreed, x2^^ I bet you do have a bad air leak. Check your flywheel side seal. Also, if this seal is OK, you may have a blown jug (cylinder base) gasket, a torn/holed carburetor boot, or damage around the reed cage. I'd do a crankcase leakdown test on the engine to help pinpoint the problem. Also, check the carburetor clamp to be sure that the carburetor is attached tightly to the intake boot.

Just a tip: I'd fix this problem ASAP, as you will damage the top end of the engine if it continues to be run with an air leak. Lean operation/hot cylinders/hot cylinder heads spell death to a 2-stroke. Also, be careful of just 'pulling the plug' on your ignition system. Removing the spark plug wire with the engine running can cause damage to your CDI box.

_________________________________________________________________

2005 Blaster
-Toomey Pipe
-VF3 Reeds
-K&N Pod Air Filter
-28mm Keihin PWK carburetor
-TORS Surgery
-Oil injection removed
-Parking brake removed
-Billet oil pump cover
-Maier Black front fenders

Upcoming Mods:
-G-Force rear axle
-RAZR's all around
-Billet rear hubs
-Works shock set


2002 Blaster-In Progress
1997 Blaster-SOLD
1999 Banshee-Upcoming Project
1994 Warrior 350-Old, reliable 4poke joke

 

[JoeymackR12x]

Thanks for your help. Could bad reeds cause this issue? i cant tell for sure but it looks like the bottom right reed isnt closing.
thanks

 

[Braaaptor]

Thanks for your help. Could bad reeds cause this issue? i cant tell for sure but it looks like the bottom right reed isnt closing.
thanks

A damaged reed by itself probably wouldn't cause this severe of a problem. It needs to be fixed, but keep on checking the engine over... Now, a blown gasket around the reed cage WOULD cause a bad air leak, so if this gasket is torn-up, that could be the issue.

I would strongly recommend pulling the flywheel and taking the stator plate off to inspect the LH main engine seal. These, and the cylinder base gasket, are known to go bad from time to time.

 

[AT Blaster]

^^Agreed x3^^

When I got my blaster I had the exact same problem.

1. Bogged down until you gave it throtle then it raced at high RPM
2. Had to unplug the CDI Box to get it to quit
3. Kill switch didn't work

Ended up having a bad crank case seal.......

There is a thread in the forums that will show you how to do a leak down test. Not sure how it works but I think that is how you would tell if you have a leak or not?

Good luck!

 

[sam0840]

this exact thing happened to me. its your crank seal. replace both sides. i am doing the right side right now... its a bit of a chore but you can do it on a nice saturday!

 

[JoeymackR12x]

Thanks for the help. I started pulling apart the motor, but before i got to far i saw that there was no gasket or sealant between the carb boot and the reed cage. looks like there was one at some point and time, but the guy that had this blaster before me was kinda of a hack. Would this cause the issues that i am having? let me know, thanks!

 

[AT Blaster]

I would think so....... But then again, I'm not a professional. I would deff take the advice of one of these guys.

Anything that causes it to get too much air would cause it to run too hot which could cause your issues!

I don't know how difficult it is to replace the crank seals (had mine done by someone else) but it wouldn't hurt to go ahead and do them as well. I don't think they are too expensive!

 

[JoeymackR12x]

Ok so, i looked into the crank case and there was no oil in the case. after i sealed up the boot and cage, i filled the case with oil and then tried starting it. when it did start it smoked me out of my garage. I am asuming that this means it is the right side crank shaft seal? is it the oil seal behind the drive gear? i was looking at the diagram on rivamotorsports.com

 

[AT Blaster]

Here is a link to a kit found on eBay

Yamaha Blaster 1988-2006 Engine/Crank Oil Seal Kit:eBay Motors (item 350244460785 end time Dec-23-09 08:02:14 PST)

 

[Impulse986]

Watched a friend really break down the motor into pennies , I'd look local on craigslist , I see bottom end in good working order for 100-150 , blasters are extremely common everywhere , 20$ bearing kit plus time invested , even at 8$ min wage , it 6 one way half dozen the other , sounds like you could possibly use the same jug n piston , check the list , if you find one cheap take it can always use the old one for parts , that is what's left of it , I'd offer you one for 120$ but the shipping based on weight Is crazy forget about the whole intake till you see how deep your tranny rabit hole goes , Hows the jug look? Any chance the piston was in backwards? Yes it runs that way I have proof , revs high but bogs on the gas , best of luck , keep us posted , I'm sure there's alot of member that would love your brother to have a nice Xmas presant : )