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

[jasons]

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

there is no timing in a 2 stroke. it has to be in the carbs. check to make sure the carbs are synced with each other. make sure the carbs are clean.

[Drewski]

there is no timing in a 2 stroke. it has to be in the carbs. check to make sure the carbs are synced with each other. make sure the carbs are clean.

 

What???

[bbcmudtruck]

Check to make sure your carbs are synched. Pull your pilot jets out and make sure they are clean. Check to see if your choke tube is connected between the carbs. Report back with results.

 

 

[jasons]

What???

thats right you heard me you dont have to time a banshee. if its running the way he says it i. its probly in the carbs. either sync them or clean them or even both.

[bansheesandrider]

thats right you heard me you dont have to time a banshee. if its running the way he says it i. its probly in the carbs. either sync them or clean them or even both.

There is not timing in the traditional sense, it will only go together one way. The stator only fits the cases one way, the flywheel only fits the crank one way, and since it is a waste spark system that fires BOTH cylinders at the same time at BOTH TDC and BDC, it does not matter which cylinder is "timed".You don't even need to put a timing light on it, unlike a car which you can install the distributor in different positions, the rotor inside the distributor in different positions and then have to sync it all together. Hell, you don't even have to time a newer car that has distributorless ignition, the ECU is self timing, you can put a light on it to check it but you can't change it, unless you modify something. Unless this guy has a coil problem, it is probably in his carbs. He needs to clean his carbs, make sure the float bowls have not been crossed from left carb to right carb, put them back on making sure everything is in good shape and hooked up properly including the choke cross over tube, and then sync them.

[moparken426]

thanks for your reponses and the info will try it all out this week and let you know how i make out and thanks again really appreciate all the help

[dicedealer702]

you can sync and clean those carbs all you want but the only way to get maxium potential out of your banshee, is not to be cheep, and get it dynoed

[moparken426]

there has to be some sort of timing on a 2 stroke it says in the manual there is but what side is #1 left or right

[jasons]

just like bansheandriders said there is no way to actuallly set the timing unless you use a timing plate and even then it doesnt matter where the piston is. it doesnt matter how or where the piston is when you put it back together either. the spark plugs are always sparking wether the piston is up or down. make sure your carbs are cleaned and are in sync. and test for air leaks.

[bansheesandrider]

The only reason Yamaha lists timing in the service manual is so that you can put a light on it and see if the advance curve in the CDI box is working. IT DOES NOT MATTER WHICH CYLINDER THE LIGHT IS ON BECAUSE BOTH CYLINDERS FIRE AT THE SAME TIME. As I said it is a waste spark system- this means that each cylinder fires at both TDC and BDC, and since Banshees are a twin cylinder that is phased 180 degrees apart, it means both cyliners fire at the same time, when the left is at TDC, the right is at BDC and vice versa. This is because a Banshee uses 1 coil to fire both cylinders- the secondary loop of the coil send the spark out 1 wire to the first plug, down the center electrode, it arcs across to the ground electrode of plug 1, traverses ground(the metal of the cylinder head) to the ground electrode of plug 2, arcs across plug 2 and travels up the center electrode of plug 2 to the other spark plug wire and back to the coil, completing the circuit. This is why when you check secondary resistance on the coil your meter leads should be connected to each plug wire and not to one plug wire and ground like the book says. A modern ditributorless car works on the same principle, except there are multiple coils, one for each cylinder pair, and they only fire each pair once per revolution because it is a four stroke.

 

The only way the timing can change on a Banshee is to use an adjustable timing plate, or a CDI box that has adjustable timing curves in it. Simply doing a top end WILL NOT change your timing because you have not taken apart anything that affects timing- the flywheel and stator positions are the only thing that affects timing. I hope this clears it up for you.