Crackerman96 Posted October 10, 2017 Report Share Posted October 10, 2017 HELP GUYS! So im leaving for a trip in two days and I'm trying to rebuild my friends banshee (my old banshee). Long story short the piston on the left side was toast and I rebuilt the top end. It was super easy to do and all I did was change the stock 347 piston to a forged wiseco 347. I didn't change anything so that way I didn't have to retune the bike. HERES THE PROBLEM: when I start the quad it fires more on the right cylinder than the left. The left barely pushes smoke at all. Also the right exhaust pipe gets hot but the left doesn't. And the best part is it back fires loud enough to hurt your ears and shoot about a 6" flame out of the exhaust. Sounds like a firecracker going off. I have a video if any body would like to see but my phone doesn't seem to let me post so let me know and I can text it to you. it has new plugs, the slides aren't in backwards, I didn't change the needle on the carbs or jetting and I'm completely lost. The only thing I can think of is somebody said there's a rubber tube that goes from one carb to the other? I see the crossover tube but it isn't rubber. Where is this located and could it cause this problem? It ran PERFECT prior to the motor losing a piston and needing the rebuild Quote Link to comment Share on other sites More sharing options...
spurdy Posted October 11, 2017 Report Share Posted October 11, 2017 But something caused it to need a piston. A perfectly good running motor doesn't burn down a piston. Sent from my iPhone using Tapatalk Quote Link to comment Share on other sites More sharing options...
Crackerman96 Posted October 11, 2017 Author Report Share Posted October 11, 2017 1 minute ago, spurdy said: But something caused it to need a piston. A perfectly good running motor doesn't burn down a piston. Sent from my iPhone using Tapatalk So he let a friend of his ride it and the friend never left first gear.. he held it first gear wide open ALL THE TIME. He continued to over heat it and finally it dropped a piston Quote Link to comment Share on other sites More sharing options...
Burke Posted October 11, 2017 Report Share Posted October 11, 2017 What's your piston to wall clearance? Quote Link to comment Share on other sites More sharing options...
Crackerman96 Posted October 11, 2017 Author Report Share Posted October 11, 2017 15 minutes ago, Burke said: What's your piston to wall clearance? Not sure, I didn't hone the cylinder, there was a single mark on it. So as far as I know it's all stock specs Quote Link to comment Share on other sites More sharing options...
Burke Posted October 11, 2017 Report Share Posted October 11, 2017 How much compression does it have? Quote Link to comment Share on other sites More sharing options...
Crackerman96 Posted October 11, 2017 Author Report Share Posted October 11, 2017 Just now, Burke said: How much compression does it have? Just tested, the left cylinder (bad cylinder) is stable at 120 Quote Link to comment Share on other sites More sharing options...
sleeper06 Posted October 11, 2017 Report Share Posted October 11, 2017 Air leak on that side, possibly crank seal Quote Link to comment Share on other sites More sharing options...
Crackerman96 Posted October 11, 2017 Author Report Share Posted October 11, 2017 6 minutes ago, sleeper06 said: Air leak on that side, possibly crank seal I don't have a leak tester, is there another way to test it? And is there anything else I should try first? Quote Link to comment Share on other sites More sharing options...
sleeper06 Posted October 11, 2017 Report Share Posted October 11, 2017 Where do you live Quote Link to comment Share on other sites More sharing options...
Crackerman96 Posted October 11, 2017 Author Report Share Posted October 11, 2017 (edited) 1 minute ago, sleeper06 said: Where do you live Sacramento California, just about sea level I believe. Also if the quad is running and I put my hand over the right carb, it sucks my hand onto it. However the left side feels like it's not drawing air Edited October 11, 2017 by Crackerman96 Quote Link to comment Share on other sites More sharing options...
sleeper06 Posted October 11, 2017 Report Share Posted October 11, 2017 I was seeing if you were close I would have tested it for you Quote Link to comment Share on other sites More sharing options...
Crackerman96 Posted October 11, 2017 Author Report Share Posted October 11, 2017 Just now, sleeper06 said: I was seeing if you were close I would have tested it for you Where about are you, I'm not exactly sac, I just say that so people know the general area. Not to many people know vacaville california lol Quote Link to comment Share on other sites More sharing options...
JUSTWANNARACE Posted October 11, 2017 Report Share Posted October 11, 2017 Choke crossover tube goes between the 2 carbs about a 3" long 1/4" od black tube. Did you pull the flywheel? Did you check the reeds? Could be a number of things but normally backfiring is from ignition timing or the crank is twisted and out of phase from one side to the other. Quote Link to comment Share on other sites More sharing options...
Ayesully810 Posted October 11, 2017 Report Share Posted October 11, 2017 I wanna see the video. post it. also you can build a leak down tester super cheap and easy to rule out air leaks Quote Link to comment Share on other sites More sharing options...
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