Switching oils

[Snoman80]

I have a 2stroke 02 blaster that's I have been running with semi synthetic oil and recently changed over to amsoil and did a 50:1 mix(was told to at closest cycle shop by me) and ever since I did, my Atv ran for 5 minutes and started to backfire and will not start anymore. I made sure to run all the fuel out before I switched over. Could use some advice on what to do. I recently got new spark plug and tryed starting again but no luck.

 

[Awk08]

That shop is fishing for work if they told you to switch fuel/oil ratios without rejetting for the new fuel/air ratio it caused.
Go back to semi-synth @ 32:1.
Then pour that 50:1 amsoil by their front door.

 

[stacypfingsten]

50:1 wow. Those guys are not good neighbors. It did run for 5 minutes though !

 

[Awk08]

50:1 wow. Those guys are not good neighbors. It did run for 5 minutes though !

50:1 is the recommended fuel/oil ratio for amsoil dominator, their saber (IIRC) is recommended 100:1
they contain extra lubricants per volume than 32:1 mix oils.
but that does not make me a fan of them.
luckily for the OP that 50:1 mix made his fuel/air ratio richer, had it been leaner it would have fried.

again....go back to semi-synth, yamalube or my prefered maxima super m and mix 32:1
98% of the jetting/tuning info on here is based on that fuel/oil ratio.

 

[stacypfingsten]

Dropping that knowledge . Thanks Awk.

 

[Blaaster]

What type of Amsoil did you use, there are different oils for different applications?

Changing to a pre mix with less oil in the mix would have caused the engine to run too rich.

Running for 5 minutes with a slightly over rich mixture should not have done any damage other than maybe foul a plug.

Although it is not recommended to switch oils in 2 strokes without flushing out the crankcase, syn and semi syn oils can usually be mixed without any problems.

So, what could now be causing it not to start? Did you do anything other than switch oils.

Could the backfire have caused to Woodruff key to break and allow the flywheel to spin causing the timing to slip?

 

[Awk08]

Could the backfire have caused to Woodruff key to break and allow the flywheel to spin causing the timing to slip?

/\ or break a reed petal.
look into both

 

[Snoman80]

I have not had the chance to buy the new oil and it's was the racing amsoil as .. everytime I would kick start it it would backfire instead of start but only after three or four kicks. As soon as I get paid Friday I will go to semi synthetic and 32:1 ratio in it and see what happens. thank you guys alot for the help and support. I will update you guys

 

[Larry's Shee]

Be sure to use a "Blaster" flywheel puller, no 2-3 jaw puller.

 

[tfaith08]

Backfiring is a sign of lean AFM. As stated above, the switch to 50:1 will make it run rich, not lean. To be exact, it will make it run 1.103% richer = don't worry about it in my book. That's the difference in a few degrees of outside temperature.

Sounds like the flywheel or a reed to me. Take the carb out and shove your phone up to the boot and take a picture with the flash on. If it's a slight crack, it won't affect starting/not running. A big chip will, however, and you'll be able to see it in the picture.

I'd run Yamalube if I was you. My dad has run it in his 94 Banshee since he bought it new and it still has the factory hone marks in the cylinders. I see no improvements to be made from there.

 

[Snoman80]

Well I changed to semi synthetic and added with new plug and no luck. I have not yet had a chance to take carb out and check anything because work and so much rain. Can someone post a link to help show how to get carb off or any tips I need to know?

 

[tfaith08]

The biggest problem is that TORS is in the way.

Turn the gas off and remove the gas line from the carb. Loosen the clamps that hold the front and back of the carb in place. The top of the carb is a screw on cap (with the big ugly box that is TORS on top of that) that is held in place by a stopper w/ one screw. Take the stopper off and you can twist the cap. When the cap comes off, you can pull the slide and needle out and you should be good to go. You can wiggle the carb loose from there.

For disassembly, click on the Blasterforum logo up top. When the page loads, go down until you see ENGINE, and below that in smaller font will be CARBURETOR. Click on CARBURETOR. The third stickied thread is "how to clean your carburetor" by jlsparky7. I'd walk you through it, but I'm on my way out the door to go to work.

 

[Awk08]

that /\
and don't forget to unhook the rubber airbox boot from that little nub it hangs from on the frame, that allows it to flex and push back allowing the carb to come out eaiser,
remember to reconnect it when done, it supports the weight of the carb better so it doesn't bounce/wiggle itself out while riding