sandshred25 Posted July 29, 2011 Report Share Posted July 29, 2011 so i recently traded for a 01 banshee,, the guy said it had a brand new top end,, i took her out to the dunes and sure enough after about 15 min of riding,she pooped out. after opening up the top end, the left piston had a whole sbout the size of a nickle blown out of it,, my ? is,, what would cause this??? one thing i found was the gear in the water pump had started to break and some of the debris was in the pump bearing,, maby over heat?? just want to avoid this,,,thanks for any help Quote Link to comment Share on other sites More sharing options...
06specialedition Posted July 29, 2011 Report Share Posted July 29, 2011 so i recently traded for a 01 banshee,, the guy said it had a brand new top end,, i took her out to the dunes and sure enough after about 15 min of riding,she pooped out. after opening up the top end, the left piston had a whole sbout the size of a nickle blown out of it,, my ? is,, what would cause this??? one thing i found was the gear in the water pump had started to break and some of the debris was in the pump bearing,, maby over heat?? just want to avoid this,,,thanks for any help Could be a number of different reasons..... Lean jetting Air leak Deto I'm sure the water pump gear problem didn't help it. I personally run the Mull billet gear, I've seen the stock plastic ones break into pieces or even start melting. Here's a link to the Mull gear: http://www.mullengineering.com/sc/store.php/products/yamaha-banshee-billet-water-pump-drive-gear-impeller-drag-race-sand-trail-power-online Hit up a site sponsor on here for your new parts, anyone will take care of you. Quote Link to comment Share on other sites More sharing options...
bansheesandrider Posted July 29, 2011 Report Share Posted July 29, 2011 The top of the piston got to hot from either being to lean or detonation or preignition. You now have aluminum in your bottom end from the piston- the top turned to liquid aluminum and sprayed all over your bottom end when it let go. You will need to get it cleaned out, I would split the cases and make sure that everything is up to spec since you don't know the history of this machine. When you put it back together, I would pull the carbs apart 1 at a time and clean them and throw in some bigger jets. Then you can do a plug chop and see where your jetting is at. AND remember, jetting is not a performance mod, it is properly tuning your setup. You also may need to run higher octane fuel to prevent preignition or detonation. I would also recomend doing some reading on here and learn your way around your Banshee so you will understand what we are talking about and we can help you faster. Good luck. Quote Link to comment Share on other sites More sharing options...
sandshred25 Posted July 30, 2011 Author Report Share Posted July 30, 2011 The top of the piston got to hot from either being to lean or detonation or preignition. You now have aluminum in your bottom end from the piston- the top turned to liquid aluminum and sprayed all over your bottom end when it let go. You will need to get it cleaned out, I would split the cases and make sure that everything is up to spec since you don't know the history of this machine. When you put it back together, I would pull the carbs apart 1 at a time and clean them and throw in some bigger jets. Then you can do a plug chop and see where your jetting is at. AND remember, jetting is not a performance mod, it is properly tuning your setup. You also may need to run higher octane fuel to prevent preignition or detonation. I would also recomend doing some reading on here and learn your way around your Banshee so you will understand what we are talking about and we can help you faster. Good luck. ive got the cases split,, been reading about detonation,, still a little confusing to me,, what it is and how to adjust it Quote Link to comment Share on other sites More sharing options...
coryv4 Posted July 30, 2011 Report Share Posted July 30, 2011 ive got the cases split,, been reading about detonation,, still a little confusing to me,, what it is and how to adjust it it usually happens when you run old gas or have high compression with low octane fuel Quote Link to comment Share on other sites More sharing options...
prssantana Posted July 30, 2011 Report Share Posted July 30, 2011 Detonation is when the fuel finishes burning before the piston reaches tdc. It is usually caused by airleaks or running the wrong jetting. Quote Link to comment Share on other sites More sharing options...
sandshred25 Posted July 31, 2011 Author Report Share Posted July 31, 2011 Detonation is when the fuel finishes burning before the piston reaches tdc. It is usually caused by airleaks or running the wrong jetting. thanks to everyone for all the tips,, makes learning fun.. Quote Link to comment Share on other sites More sharing options...
LS3 Machine Posted July 31, 2011 Report Share Posted July 31, 2011 Detonation is when the fuel finishes burning before the piston reaches tdc. It is usually caused by airleaks or running the wrong jetting. Or too low Octane for the compression that you are running. My comment on what happened: The guy was probably telling the truth about it having new pistons. He probably put new exhaust or did some other type of upgrade to the bike, didn't adjust the jetting at all, or adjusted it improperly, blew a piston, got nervous because he didn't know WTF he was doing, and put new pistons in and sold the bike without correcting the root cause of the problem (lean/poor jetting). Im speculating a bit, but this type of thing happens al the time. The wierd thing is that these bikes are pretty easy to work on, and jetting is pretty easy. Keep us posted on your progress, and I agree with the above reccomendations. Once you get the new top end reassembled (it would be a great time to do some porting if your budget allows it), definately put in bigger jets (Id go 2 sizes at least to start with), and then re-chek your jetting (by checking the plugs). When you get your replacement parts from a forum vendor/shop, they will be able to also sell you the right size jets for your setup. That's the good thing about the forum vendors, they already know what works. Good luck and keep us posted. Quote Link to comment Share on other sites More sharing options...
sandshred25 Posted August 1, 2011 Author Report Share Posted August 1, 2011 once again, thanks to everyone with all the help,, every bit goes a long way in my book,,.. i decided to go with Kevin Herr ,, after reading about him (on this site) and talking with him on the phone, i feel very confident with the service he will provide,, all parts are being shipped tmrw morning,, i look forward to updating everyone with progress. i have always felt a little overwhelmed with these dang bikes ,,, until i came across this site,, makes it fun thanks to everyone.. Quote Link to comment Share on other sites More sharing options...
LS3 Machine Posted August 1, 2011 Report Share Posted August 1, 2011 once again, thanks to everyone with all the help,, every bit goes a long way in my book,,.. i decided to go with Kevin Herr ,, after reading about him (on this site) and talking with him on the phone, i feel very confident with the service he will provide,, all parts are being shipped tmrw morning,, i look forward to updating everyone with progress. i have always felt a little overwhelmed with these dang bikes ,,, until i came across this site,, makes it fun thanks to everyone.. Yeah I've read about more happy customers with Kevin than anyone here. He will set you up good, and tell you the exact jetting you will need. Quote Link to comment Share on other sites More sharing options...
Burt Reynolds Posted August 1, 2011 Report Share Posted August 1, 2011 crank seal maybe Quote Link to comment Share on other sites More sharing options...
sandshred25 Posted August 1, 2011 Author Report Share Posted August 1, 2011 wanted to mention,, i called kevin (HJR) early sat morning,, he returned my call within the hour,,ON A SATURDAY!,,, that sealed the deal for me Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.