Running out of ideas of whats wrong help!

[Brandon54]

Ive owned this banshee for 2 years now always worked perfect and kept tuned. Running mild mods nothing too heavy. All of a sudden it quit running on the left cylinder or intermittently. I took off carbs cleaned as well reeds new gaskets. Checked for vacuum leaks, Still has tors but disconnected and sealed properly. Compression 123 psi each cylinder. Head gasket is good so is base. Jetting is good. Run 260 on the main. gas is fresh as can be mixed 40;1 No matter what I try I cant figure it out. someone mentioned crank seal? no clue please help!   

 

Mods. FMF fatty , powercore 2's ,vforce reeds, .20 over wiesco pistions , jets , kn filter, dirt digger clutch

Edited June 29, 2014 by Brandon54

[rubberneck]

swap plug wires side to side see if problem follows the wire to the other side or stays.  if it moves to other side its ignition.  if it stays you need to look deeper.  could be as simple as a bad plug cap.

[03DMshee]

Whats your elevation? 260 seems a tad lean for those pipes...and you did a leakdown test?

[Brandon54]

I have swapped the spark plugs , put new ones in along with new caps and checked the resistance on the coil . Alls is good. Haven't performed a leak down test , need to get a tester . Would a crank seal make the left side not fire ? I know it's common for that to occur on the right side. Yeah maybe I should raise the jets , the main problem is it won't idle and kinda back fires . I think maybe a larger pilot? The screws are out 1/2 just to make it run

[rubberneck]

you said you swapped plugs but did you swap wires side to side?  See what im getting at?  Did you make damn sure the carbs are immaculate clean? a clogged idle circuit could cause this as well

[Brandon54]

Yes I did swap the wires aswell same thing . I'm positive the carbs are clean. I'm still kind of new how exactly do I check the idle circuit ? Btw 275ft above sea level

[wayne_smith97]

When you cleaned the carbs did you actually take the pilot jets out and clean them?

[Brandon54]

Yeah. It still has stock 25 pilot in it . Big deal ? I know when I put those pipes on Fmf called for a 30 pilot but that's way too rich

[wayne_smith97]

27.5's and do a leak down test

[Larry's Shee]

Check for mouse nest in pipe. Clean timing nubs on flywheel and set gap with feeler gage, check at both nubs.

[Brandon54]

Best place to get a leak down tester ? Can you replace the left crank seal without splitting case ?

[wayne_smith97]

Make your own. There is a walk thru on here or talk to sprinklerman

[trickedcarbine]

Here's a misc. list I keep around for electrical.

 

Trouble shooting list

 

Flywheel and key (no rattles good magnetically)

Stator (ohmed and tried 4 known good stators)

Pick up and pick up gap (even filed nubs even)

Wiring harness Un wrapped and gone through

Plugs and connectors cleaned and greased

New spark plugs

Clipped plug wire ends where boots thread in

New plug boots

Ohmed and tried several known coils

Coil surface grounded and cleaned w/ dielectric Harness ground cleaned up

Tors/park brake/key/tps/ all deleted

Disconnected the tether switch

Test kill switch

Swap CDI

 

At the CDI harness side connector, check for continuity between the red/black wire and the black wire. You should have continuity with the key on. (or bypassed) If no continuity, there's your problem. If that checks, check between the black/white wire and the black wire. That's your kill switch. It should be open circuit for it to run.

 

You got it. We noted and have posted many times, the typo that Clymer did in their manuals. Primary is from blade connector to blade connector and secondary is from plug wire to plug wire. Remember to remove the plug caps and test separately. They are known for failures . Remember also to unclip the wires completely from the coil and test "ONLY" the coil when you get a bad reading. Wires shit out commonly, the coil itself rarely fails.

 

your ignition has 4 wires. cut the ignition off. the black with white stripe and red with brown stripe need to be soldered . then solder the red and brown wires so you then have 2 wires. wrap them up in electrical tape (NOT TOUCHING) then your ignition will be eliminated.

 

the coil grounds where it mounts, and there is one on the back of the timing plate- it's the wire clamp. that is the whole engine ground. there is also one by the voltage regulator.

[trickedcarbine]

If it's not electrical

 

Leak down ( there is an awesome write up on making one here)

Systematically check carbs

- fully disassemble them

-clean them

- blow all offices out with air

- re assemble with slides in correct position

-check choke tube

-check bowls are oriented correctly

[Brandon54]

My kill switch barely works . I have to keep moving it back and fourth to try to get it to shut down. The odd time I have to stall it . I thought it was the band in the switch ? Could that be a cause for it not idling right?