rox10h Posted November 24, 2010 Report Share Posted November 24, 2010 hey guys..have a bit of a problem with my sheee ok so im not technically minded what so ever with engines so bare with me. basically to cut a long story short, the engine has been running as normal lately but the powerband wouldnt kick in. i could also hear a continuous tapping/rattling noise, as if something was hitting something else as the engine was running. the bike would kinda limp then hit the powerband softly, but there was no arm-outta-socket power at all. i had a friend to change the spark plugs. put brand new (and correct) plugs in, fired it up, rev'd it for 2 seconds, the kickstart siezed (it siezed 2 weeks ago but i bumped started it and it was fine after), and the piston has shattered! it looks like the piston has hit the spark plug? the sparkplug's end was inolated from what ever had hit it. it was even chipped. now your going to have to bare with me as my friend is the bike know how, but from what i gather off my mate i need: a new piston, conrod, head, full gasket set, crank bearings, sparkplugs and bore and hone. a specialist who's advert is on ebay has said that ''first thing is crank big end has gone this is why the piston hit the plug. crank rebuild from 199.00 + but with big end going will need web sp around 250.00 thats the bottom end sorted.. top end rebore + pistons £155.00 fitting for all parts is £120'' ...has anyone else experienced this problem, or a simular one? its done my head in tonight i feel like crying lol. appriciate your help in advance Irfan if Quote Link to comment Share on other sites More sharing options...
camatv Posted November 24, 2010 Report Share Posted November 24, 2010 umm the plugs are not what caused your motor to blow.. its just blowed up. i'm stoping there. Quote Link to comment Share on other sites More sharing options...
rox10h Posted November 24, 2010 Author Report Share Posted November 24, 2010 well thanks very much for that really helpful post. Quote Link to comment Share on other sites More sharing options...
Larry's Shee Posted November 24, 2010 Report Share Posted November 24, 2010 (edited) You have initial failure and then you get collatteral damage. Post some pics of the carnage. General consensus here in U.S. is that it ends up being cheaper and better to get a new crank that's trued and welded. Unless you put a plug with a2 in nose on it in , it is impossible for the piston to hit the plug because of the dome .Don't know if big end failing would cause piston to fail,sounds fishy to me ,don't matter really , it's broke. Blew a Suzuki T-500 once that only top of piston was left, did piston fail causing pin to drop into transfer or did pin drop into port exploding piston? Don't know , didn't matter it was fucked . Edited November 24, 2010 by Larry's Shee Quote Link to comment Share on other sites More sharing options...
12 0 Clock P I M P Posted November 25, 2010 Report Share Posted November 25, 2010 What is your current motor set up..pipes....carbs...jetting....sounds like you had detonation in the engine and it took a dump on you.....something is walking around in your motor if your piston is hitting the plug end.......break your engine down to make sure your cylinders are ok.....if any damage a bore and hone will need to be done......sounds like u will need a crank too........get the next crank trued and welded...for durability sounds like u had an issue when ur kicker locked up first..... Quote Link to comment Share on other sites More sharing options...
J-Madd Posted November 26, 2010 Report Share Posted November 26, 2010 When it locked up the first time, it probably had a broken piston skirt and pieces of thebroken shirt got on top of the piston and into the spark plug. Or the piston seized; then damage to the piston/rod, etc occured when you pull started it. Just a theory... Those prices listed are high (in US dollars.) Also, anytime a motor even tries to lock up; tear it down and inspect it. I had some crank bearings going out and it would drag the motor down so that it wouldn't idle (just about to lock up.) I tore it down and didn't find any damage (not even the bearings) but replaced the questionable crank bearing anyway. Ran fine after that. Quote Link to comment Share on other sites More sharing options...
midlifecrisis Posted November 27, 2010 Report Share Posted November 27, 2010 What did the top of the piston in question look like? Did it have a bunch of small 2-3mm circular dents in it? Check to make sure that the electrode from your plug isnt missing, check your piston wrist bearing to see if all the bearings are accounted for. You wanna make sure you have all of the schrapnel out of the bottom end before reassembly. As the previous guys have said, often times when a kicker locks up, some assume its the kicker gear that just needs a bit of movement to free it up, when in fact, its usually the first sign of a piece of crap stuck under your crank between it and the bottom case. Not sure what the guy is talking about, whos trying to sell you parts, but I have copied your quote from him, and I will send it to my old man (whos a die hard Brit, and a wicked builder) , for a 2nd opinion. There is no way on a stock head, that a piston can hit the spark plug, unless your plug is 3/4" too long? What plugs are you running? Thats a wrist pin bearing by my finger. Quote Link to comment Share on other sites More sharing options...
n2otoofast4u Posted November 28, 2010 Report Share Posted November 28, 2010 What did the top of the piston in question look like? Did it have a bunch of small 2-3mm circular dents in it? Check to make sure that the electrode from your plug isnt missing, check your piston wrist bearing to see if all the bearings are accounted for. You wanna make sure you have all of the schrapnel out of the bottom end before reassembly. As the previous guys have said, often times when a kicker locks up, some assume its the kicker gear that just needs a bit of movement to free it up, when in fact, its usually the first sign of a piece of crap stuck under your crank between it and the bottom case. Not sure what the guy is talking about, whos trying to sell you parts, but I have copied your quote from him, and I will send it to my old man (whos a die hard Brit, and a wicked builder) , for a 2nd opinion. There is no way on a stock head, that a piston can hit the spark plug, unless your plug is 3/4" too long? What plugs are you running? Thats a wrist pin bearing by my finger. The "big end" that he is referring to is the big end of the rod.(where it attaches to the crank) What more than likely happened is that the rod bearing went bad, and that what was causing the knocking or banging noise that you were refering to. From there the piston is then allowed to moved different places in the bore because of the slop created by the bearing not being good incuding going up to high and hitting the dome. After repeated times of it doing that it finall cracks and breaks the piston and the pieces get shoved around by the remaining piston, smashing that shit out of the plug, and everything else along the way.. Best way to fix? Most likely cheaper to buy a complete used crank. (the parts to fix yours will be more than you can buy another for) Depending on the damage to the cylinder, and your portwork, either have it bored or buy a used cylinder. Your gonna need new pistons as well as a complete gasket set. I would suggest while its apart putting the new crank in, to take a ood long look at all components in the motor. No time like now to fix it up.. Be sure that the crank you use has been trued and welded.. Quote Link to comment Share on other sites More sharing options...
AKheathen Posted November 29, 2010 Report Share Posted November 29, 2010 pics will tell the whole story........it could also have been something as simple as a plugged main jet, which can run that cylinder and that side of the crank dry, or melt it down. it may seem like "broke is broke" but you don't want it happening again from something so menial. one good reason to check things out when it's not running right... many things it could be.........as for the crank, yes, just replace it, once the webbing gets damaged. don't just trust any old used crank though, you want a low-hours, recently rebuilt, trued/welded, or best thing is new.... Quote Link to comment Share on other sites More sharing options...
rox10h Posted December 3, 2010 Author Report Share Posted December 3, 2010 wow forgot to check this thanks to the first unhelpful post i had! thanks for your input guys it means a lot! i havent had time to take pics, seen as the engine went bang at my friends house so now the she will stay up there till my engine is back! The engine itself is having: a brand new crank, pistons,gasket set,my head can probably just be machined, and i need a new right side cylinder as mine is just wrecked. now the funny thing is, that the banshee is the most popular and respect quad of all time YET finding parts for them in the uk is like finding rocking horse shit! the replacement right side cylinder has been ordered from you guys in the States haha. fingers crossed il have it all in the bike up and running by a week today! again thank u for the responses guys, top class knowledge as always. Quote Link to comment Share on other sites More sharing options...
AKheathen Posted December 4, 2010 Report Share Posted December 4, 2010 did you pick up a cylinder from one of us, or a brand new one? Quote Link to comment Share on other sites More sharing options...
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