MOTOR REBUILD

[moparken426]

i just rebuilt the motor in my son's banshee witch pistion the left or right has to be top dead center to time it ,because i have the left pistion now and it runs like sh@t ,right now it runs on the left side and some times when you rev it up it will run on the right side can anyone give me a good idea what is wrong .

thanks for any help at all

[bonerific250]

2 strokes do not need to be timed. sounds like it might be a stator or coil issue. did you do anything with the carbs when you did the rebuild?

[moparken426]

i am cleaning carbs right now, i tryed another coil and same thing ,but why in the shop manual does it say to time the motor....

[BigRed350x]

Not sure what manual you are reading off of, but here's a basic rundown of setting up the ignition on your banshee...

 

With the flywheel off, your stator is bolted to the engine in 3 places. Now, depending on if you have an adjustable timing plate or a stock one it changes how you set things up. With the adjustable plate your 0 mark gets lined up with the hair-line split between the case halves at the 3-oclock position as your looking at your engine from the side. (crank center line at the center of the clock) If you run a stock timing plate then you can't adjust it. Just make sure when you install the stator/timing plate that your pickup coil is down around the 5-oclock position.

 

Next, put your keyway in your crank (I like to secure mine with a little dab of threebond and let it set up before you install the flywheel. Helps keep the key from moving around when your installing the flywheel. Then just make sure the flywheel keyway is lined up with the key on the crank you just installed and slide the flywheel into place. Torque the flwyeel nut to spec. I like to use an impact for this, but be careful, I've seen people go too much with the impact and snap the end of the crank off.

 

Then just hook up your wires. If you're losing spark, the first thing I'd check is your pickup coil gap (we set them to .018") then try new plugs, then new plug caps. If still no spark, try and swap out the coil (cheapest) if still no spark, then do the stator next. This is all assuming you've check your harness for loose connections and good grounds.

 

That should be a good start.

[BigRed350x]

Forgot to mention that the key on the crank DOES NOT hold your flywheel from spinning on the crank. The taper of the flywheel and the taper of the crank are a matched set and press together. This is what holds the flywheel on the crank, and why it is critical to get your flywheel nut torqued down good. The key is just there to ensure proper flywheel alignment before and while your torque it down.

 

If you have an aftermarket flywheel or crank the tapers often times don't line up perfect. Louie at twister told me to use blue loctite on the taper of the crank and flywheel to help make sure everything isn't going to move once its all together. Just remember you have the loctite on there before you try and remove the flywheel, since you'll need to heat it up with a propane torch before you try and zip the flywheel off.

[moparken426]

i tryed a different coil and new plugs,still the same thing wont run on both cylinders alway on the left side it will run only when you can get it to turn up it will run on the right side on and off ,could it be the stator that is bad or the cdi box on the back of the bike ,dont make any sence ,could it be maybe the reeds not working right,

[moparken426]

i tryed a different coil and new plugs,still the same thing wont run on both cylinders alway on the left side it will run only when you can get it to turn up it will run on the right side on and off ,could it be the stator that is bad or the cdi box on the back of the bike ,dont make any sence ,could it be maybe the reeds not working right,

aslo the bike is back firing though the exhaust

[tonyown]

Did u put back the little tube betwen the 2 carbs? I made this mistake first time i changed piston didnt know that this tube was important and it ran on 1 cyl like u.

[moparken426]

yep i did but the tube is not 100% tight could that be it , that would really suck if it was that simple

[tonyown]

I don't know it's normaly tight without any clamps... anyway I had same problem as you and it worked well when I put back the litle tube back between carbs lol take a look to be sure that it's at the right place if it is I don't know what's your problem...

cya

[BigRed350x]

Start swapping parts cylinder to cylinder. Plugs, wires, carbs, reeds, intakes, etc... see if the problem jumps to the other cylinder when you change parts. Backfiring is usually a lean condition or an air leak. This could explain why its not running on both cylinders. Did you do a leak-down test after you rebuilt the top end?

 

- Jared

[moparken426]

no i didnt do a leak down test i guess i will have to take the motor out again and do that ,i put a new wisco crank all new seals ,bored it .50 thou new wisco pro lite pistions all new top end gaskets , now i and frustrated cause i cant get it to run it sucks

[tonyown]

Why would u take the motor out to do a leakdown test? You can do it with the motor in frame...

[banshee 268]

Why would u take the motor out to do a leakdown test? You can do it with the motor in frame...

before you pull the motor make sure to check and make sure ur slides are in the correct carbs.mine ran just as u explained and it was the slides.the right and left got switched around.

[jpringle83]

x2 on the slides. I did the same thing and if you could get it started it ran like complete crap.