coleman66six Posted May 11, 2019 Report Share Posted May 11, 2019 OK so I was riding last weekend when my banshee started to run off one cylinder, I pulled over and realized that I lost all my compression in my left cylinder. I got the quad home and took it apart yesterday hoping it was just rings. I took off the left cylinder and the piston was destroyed along with the left cylinder, hole through the side of the piston. So since I knew it was definitely more than rings I decided to take off the right cylinder also. The right cylinder and piston was mint and had normal wear and almost no wear at all. The quad only had about 5 hours on the top end when this happened. I was running Vito's superstock pistons (which I have heard bad things about, but I was hoping they would actually add 8+ hp so I got them anyway), and before that it had the stock top end which also looked very nice. So basically now I am just wondering if I should investigate why only the left side went, or was it just bad quality pistons??? I am thinking of going with a Wiseco top end and getting new cylinders but I am worried that the same thing might happen to the left cylinder again, so I wanted some opinions of people who know a lot more than me. Was it just bad quality pistons or is there something wrong with the left side of my engine????? Also wanted to add when I did the top end before I did split the case cause I had a welded ball and rod. Any help is appreciated, thanks. Will try to answer any questions. Tried to add photos but they were to big. The kit I am thinking about getting: https://bpracingatv.com/index.php?route=product/product&product_id=659 Quote Link to comment Share on other sites More sharing options...
gusto Posted May 11, 2019 Report Share Posted May 11, 2019 Post up some pictures of the carnage and we might be able to figure out what happened. could be bad chamfer job, air leak, detonation problem, done problem, crank problem, etc etc ive seen stock boots crack and you’d never know until you had them off and looked at them. That’s why leak down tests are so important 1 Quote Link to comment Share on other sites More sharing options...
coleman66six Posted May 12, 2019 Author Report Share Posted May 12, 2019 3 hours ago, gusto said: Post up some pictures of the carnage and we might be able to figure out what happened. could be bad chamfer job, air leak, detonation problem, done problem, crank problem, etc etc ive seen stock boots crack and you’d never know until you had them off and looked at them. That’s why leak down tests are so important I tried and it just says every single picture is to big, I took them on my phone so idk why I can’t post them here. Quote Link to comment Share on other sites More sharing options...
gusto Posted May 12, 2019 Report Share Posted May 12, 2019 Use Tapatalk 1 Quote Link to comment Share on other sites More sharing options...
coleman66six Posted May 12, 2019 Author Report Share Posted May 12, 2019 2 hours ago, gusto said: Use Tapatalk Alright, good idea, hope this works. https://www.tapatalk.com/groups/banshee/viewtopic.php?f=2&t=2 Quote Link to comment Share on other sites More sharing options...
gusto Posted May 12, 2019 Report Share Posted May 12, 2019 (edited) Lean condition! You had an air leak, wrong gas mixture, wrong octane for your compression, or maybe too hot of a spark plug or wrong jetting. what mods do you have? High compression domes? You probably had an air leak and if you would have done a leak down test you could have caught it. SouthTexasBanshee sells a leak down tester for cheap, you’ll need it for your rebuild Edited May 12, 2019 by gusto 1 Quote Link to comment Share on other sites More sharing options...
coleman66six Posted May 12, 2019 Author Report Share Posted May 12, 2019 3 hours ago, gusto said: Lean condition! You had an air leak, wrong gas mixture, wrong octane for your compression, or maybe too hot of a spark plug or wrong jetting. what mods do you have? High compression domes? You probably had an air leak and if you would have done a leak down test you could have caught it. SouthTexasBanshee sells a leak down tester for cheap, you’ll need it for your rebuild Alright good to know. The jetting to me seemed fine, I rejetted it a few months ago and put 380 for the mains in both carbs and synced them. The plugs looked a perfect color to me even a little rich. I run 91 octane at 32:1 with amsoil. My engine mods are, Vito’s super stock pistons, k&n air filter, the jetting I mentioned, adjustable timing plate which was set at 0, so stock timing, Vito’s clutch plates and fibers, pancake bearing, FMF fattys Gold series, FMF silencers. I run BR9ES in the quad. I do not have high compression domes. If I recall correctly I had around 120-130 psi compression. Also, how does a leak down test work? Do you need any special tools? Thanks for the replies. Quote Link to comment Share on other sites More sharing options...
gusto Posted May 12, 2019 Report Share Posted May 12, 2019 You’ll be super rich with those main jets. I would imagine you have a 27.5 pilot. Anyway it’s most likely a air leak that caused the lean condition. 1 Quote Link to comment Share on other sites More sharing options...
coleman66six Posted May 12, 2019 Author Report Share Posted May 12, 2019 1 minute ago, gusto said: You’ll be super rich with those main jets. I would imagine you have a 27.5 pilot. Anyway it’s most likely a air leak that caused the lean condition. Just realized I said 380, I meant to say 290’s lol my bad. Also to add I ride about 800ft above sea level and it’s usually around 60 degrees Fahrenheit. Thanks for all the help. Quote Link to comment Share on other sites More sharing options...
coleman66six Posted May 14, 2019 Author Report Share Posted May 14, 2019 On 5/12/2019 at 9:03 AM, gusto said: Lean condition! You had an air leak, wrong gas mixture, wrong octane for your compression, or maybe too hot of a spark plug or wrong jetting. what mods do you have? High compression domes? You probably had an air leak and if you would have done a leak down test you could have caught it. SouthTexasBanshee sells a leak down tester for cheap, you’ll need it for your rebuild I just ordered the leak down tester yesterday, when I get it I’ll have the top end in and I’ll do the test and update you. If it’s not a air leak then I’ll be completely lost lol. I’ll get back to you as soon as I do the test though, thanks. Quote Link to comment Share on other sites More sharing options...
Ayesully810 Posted May 14, 2019 Report Share Posted May 14, 2019 (edited) anytime something like that happens, always pressure test before you pull everything apart that way you can use process of elimination if there was no air leak and rule that out. I know bp is a sponsor here but ive rarely seen anything good said about them besides how cool their website looks, do some research or random poll on bhq facebook page before choosing them. Look into driveline, fast, redline, macdaddy and have them bore your cylinders and set you up with new pistons and be done with it as far as your top end. idk how much carnage was done on that side but you might wanna check that crank to see if any piston made its way into the case, if so splitting it would prolly be wise since your buying a whole new top end. Edited May 14, 2019 by Ayesully810 1 Quote Link to comment Share on other sites More sharing options...
coleman66six Posted May 14, 2019 Author Report Share Posted May 14, 2019 1 hour ago, Ayesully810 said: anytime something like that happens, always pressure test before you pull everything apart that way you can use process of elimination if there was no air leak and rule that out. I know bp is a sponsor here but ive rarely seen anything good said about them besides how cool their website looks, do some research or random poll on bhq facebook page before choosing them. Look into driveline, fast, redline, macdaddy and have them bore your cylinders and set you up with new pistons and be done with it as far as your top end. idk how much carnage was done on that side but you might wanna check that crank to see if any piston made its way into the case, if so splitting it would prolly be wise since your buying a whole new top end. Hey man thanks for the reply. I already ordered the bpracing kit, since I have a ride coming up fast so, I hope it is a decent kit. Not sure if it could have been bored because there was nasty damage to the cylinder walls. I did look down into the crank and there was no pieces of metal visible in there, but I flushed it about 8 times anyway. The site claims to be good as OEM, but who knows. Plus I have always thought wiseco was good at making pistons, not bottom ends though. Thanks for the tips too. Quote Link to comment Share on other sites More sharing options...
coleman66six Posted May 21, 2019 Author Report Share Posted May 21, 2019 Lean condition! You had an air leak, wrong gas mixture, wrong octane for your compression, or maybe too hot of a spark plug or wrong jetting. what mods do you have? High compression domes? You probably had an air leak and if you would have done a leak down test you could have caught it. SouthTexasBanshee sells a leak down tester for cheap, you’ll need it for your rebuild Well the test is done on the new top end, I can hold 6 psi for 6 mins with losing a little bit of pressure slowly. Sprayed the whole engine with soap and water and could not find air leaking from anywhere. Also decided to do a compression test and both cylinders are around 130 psi. So, do you think the air leak was in the old cylinders and top end or do you think something else caused the hole in the piston? I am running the new setup on Monday so any tips would help. Also added some plug pics for jetting reference. Thanks. Quote Link to comment Share on other sites More sharing options...
gusto Posted May 21, 2019 Report Share Posted May 21, 2019 Ok synch your carbs now. You have two different plug readings. Check your jet sizes make sure they match and air flow your carbs. The tool is worth the $35. You can also use SouthTexasbwebsite he shows how to do it 1 Quote Link to comment Share on other sites More sharing options...
coleman66six Posted May 21, 2019 Author Report Share Posted May 21, 2019 Ok synch your carbs now. You have two different plug readings. Check your jet sizes make sure they match and air flow your carbs. The tool is worth the $35. You can also use SouthTexasbwebsite he shows how to do itI had them synced a couple weeks ago by a shop for 80$ cause I did not have the tool. I could hear a difference before and after so I think it was done right. Chippewa Motors. So what else should I do before Monday? Thanks. Quote Link to comment Share on other sites More sharing options...
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