Jump to content

Backfiring out of right side tail pipe


Recommended Posts

My restore is doing the exact same thing right now -- EXCEPT! I can get mine running.

 

My float needles seat on the right is a little bit leaky. I tried polishing it up with some chrome polish, a q tip, and a drill today but it didn't quite fix it. I might either swap carburetors and plug off the choke, or figure out something else because its just not working. I just went through my wiring to make sure there was no visible wiring problems. I have also tried a Known good coil.

 

I had the same thought with the ignition not being able to produce a spark for TWO cycles, but does it always discharge left first? it fires on the upstroke and downstroke both times though!

Link to comment
Share on other sites

The banshee's ignition system is setup as a waste spark system......when it sparks it sparks both plugs at the same time.  That's why we always suggest people swap plug wires on the jugs to help eliminate whether they are having a ignition problem or a fuel problem.  question is why is your bike only firing one plug.....

 

have you tried checking the ignition system with a ohm meter?  The easist thing to replace is the plug wires which alot of guys have had issues with before.  If the resistance in one of your wires is too high it could keep it from sparking....

 

report back with your findings

Link to comment
Share on other sites

Wow, same thing here MacDaddy!!!!!

Backfiring out of both, but only after I swapped plugs over. So it is more like a consequence of the right side backfiring - it eventually makes the left side follow.

 

I thought the left side would clean it up. I run crappy oil.

 

I swapped ignition coil, I swapped the cdi box. I am super fortunate to have another set of stock carburetors from my friend.

 

New plugs ( non resistor B8ES ( not b8hs, they are short plugs doh! ) new plug wire caps - NGK Resistor caps from local dealer - test

If not working

 

New carburetors

If not working - go crazy and

swap coil again, rebuild harness, pull flywheel and check magnets? make sure the keyway is in.

My ignition is set up at -1degree retarded. I haven't tried advancing it any. Sounds like a lot of people like running it advanced but honestly to me that creates heat, and I want to break in my motor but I don't want anything Extra heat

Link to comment
Share on other sites

My next thing afterward would be to clear out the exhaust / bake / decake it. I have left my banshee with no plug to help drain that side if I have a fuel buildup in the bottom of it.

 

Previous owner installed a new coil set ( the stator plate is all shiny ) so I suppose he could've done something wrong. I will pull that apart as well. I couldn't get the flywheel off last time <_could be my problem_> I have 2 pullers that are left hand thread and match the banshee BUT it wasn't coming off! So maybe I unseated the flywheel. but I did torque it down again.

 

I wiggled the flywheel. there is only a miniscule amount of side to side play, no in and out.

Link to comment
Share on other sites

Op says hes rebuilt and has 120psi, Im at ~ 80psi both cylinders but the compression test is flawed because the compression tester is an automotive, large cc application tester with a 2 foot hose on it. Either that or my squish is set so large that I have no compression but I'm running Pro-Lite pistons for a Banshee. Base gasket/head gasket are normal and not extra thick or anything. I tried using a piece of solder to check my squish and It didn't smush it, Im probably at like 2mm for a squish band around the outside of the pison edge.

Sorry forget to mention, I did a compression test and I got 120 psi on each side. And don't think it's the coil because I flipped ignition wires and the problem didn't switch cylinders. Reeds looked fine when I put them in but I will swap reeds and see if it follows cylinders. Thanks for the help. If you get any more ideas keep them coming. I appreciate it.

Link to comment
Share on other sites

Op says hes rebuilt and has 120psi, Im at ~ 80psi both cylinders but the compression test is flawed because the compression tester is an automotive, large cc application tester with a 2 foot hose on it. Either that or my squish is set so large that I have no compression but I'm running Pro-Lite pistons for a Banshee. Base gasket/head gasket are normal and not extra thick or anything. I tried using a piece of solder to check my squish and It didn't smush it, Im probably at like 2mm for a squish band around the outside of the pison edge.

Holy shit.......if its not smashing solder then you have some serious issues. IIRC I believe the solder itself is 2mm thick. I would find a different compression tester......just to be sure. I don't think the length of the hose can give issues as long as the schrader valve at the end of the hose is still good....it should just fill the hose and then let the next cranking compress what is trapped in the hose.

 

If 80 is correct.....you need a bore and hone BAD. I've seen 80 psi not be even able to start on dirt bikes.....

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...