sredish Posted June 26, 2012 Report Share Posted June 26, 2012 (edited) Lower end was never my specialty. Pretty fresh Banshee here, not many hours on it. Did the top end on it like a year ago. It ran friggin hard and super nice, plugs always looked good but again, not many hours on it. Put some fresh fuel in, everything looked good, started right up. Ran it for a few then killed it. When I killed it, I heard a clunk; wasn't sure what it was. So, went to start it today and definite clunk in relation to the kicker. I could rock the kicker and repeat the clunk. Tear down commenced. Pistons had some heat marks on skirts, could see a little vertical wear marks on the cylinder walls. Appears that it didn't lube properly or the oil wasn't right but, I'm not an idiot, this isn't my first banshee and everything was done like it has in the past w/o issue. Dunno what happened this time. Anyways, took a vid of the clunk when I got the top end off. You can hear the clunk when I rock the crank. If I push down on both the connecting rods, they're tight as heck, so not sure if it's a bearing issue or something else but there's no play back and forth with the rods, just the rocking. Don't have a lot of lower end experience and haven't specifically heard this clunk before, although I'm guessing it's probably going to need a crank.... Link to vid (can't remember if we can or how to embed here) http://youtu.be/ft9VbIaifNc Edited June 26, 2012 by sredish Quote Link to comment Share on other sites More sharing options...
booxzzy Posted June 27, 2012 Report Share Posted June 27, 2012 The same thing happened to me on yfz450r,ended up getting new crankcase, new crankshaft,cylinder and piston because pieces of bearing fuked it all up. Didnt even have time to take it for a spin and damn thing went appart =/ Quote Link to comment Share on other sites More sharing options...
n2otoofast4u Posted June 27, 2012 Report Share Posted June 27, 2012 The same thing happened to me on yfz450r,ended up getting new crankcase, new crankshaft,cylinder and piston because pieces of bearing fuked it all up. Didnt even have time to take it for a spin and damn thing went appart =/ 2 total different setups. Just pull it apart. Its simple. Just pay attention draw pictures make notes. Quote Link to comment Share on other sites More sharing options...
booxzzy Posted June 27, 2012 Report Share Posted June 27, 2012 2 total different setups. Just pull it apart. Its simple. Just pay attention draw pictures make notes. It is different but not much,still piston is a piston and crankshaft is the crankshaft no matter is it 2 stroke or 4 stroke. Quote Link to comment Share on other sites More sharing options...
Jereme6655 Posted June 27, 2012 Report Share Posted June 27, 2012 It is different but not much,still piston is a piston and crankshaft is the crankshaft no matter is it 2 stroke or 4 stroke. correct me if im wrong here.....doesnt the 450 case split down the middle like most dirtbike cases......as in it has a left side and a right side? now how is that "different but not much" than a banshee lower end where the cases have a top half and a bottom half. and how do you think that a 2 strokeand a 4 stroke motor are relatively close.......about the only relation they have to each other is both run pistons and both have spark plugs.....so really there's not much similar between them.... Quote Link to comment Share on other sites More sharing options...
booxzzy Posted June 27, 2012 Report Share Posted June 27, 2012 correct me if im wrong here.....doesnt the 450 case split down the middle like most dirtbike cases......as in it has a left side and a right side? now how is that "different but not much" than a banshee lower end where the cases have a top half and a bottom half. and how do you think that a 2 strokeand a 4 stroke motor are relatively close.......about the only relation they have to each other is both run pistons and both have spark plugs.....so really there's not much similar between them.... i think he was talking about crankshaft noise so i said i had the similar problem on my yfz450r so why would u on earth bring up differences between 4 strokes and 2 strokes and their setups. and again no matter is it 2 stroke or 4 stroke crankshaf does the same job on both of them. correct me if im wrong. Quote Link to comment Share on other sites More sharing options...
sredish Posted June 27, 2012 Author Report Share Posted June 27, 2012 i think he was talking about crankshaft noise so i said i had the similar problem on my yfz450r so why would u on earth bring up differences between 4 strokes and 2 strokes and their setups. and again no matter is it 2 stroke or 4 stroke crankshaf does the same job on both of them. correct me if im wrong. well, the rods are tight as hell, thinking it must be a bearing issue or something. thinking i might sell some parts now as the quad isn't in full sale condition. pt hi's, carbs and ported cylinders. Quote Link to comment Share on other sites More sharing options...
Jereme6655 Posted June 28, 2012 Report Share Posted June 28, 2012 i think he was talking about crankshaft noise so i said i had the similar problem on my yfz450r so why would u on earth bring up differences between 4 strokes and 2 strokes and their setups. and again no matter is it 2 stroke or 4 stroke crankshaf does the same job on both of them. correct me if im wrong. the crank a 4 stroke is a self bathing style......2stroke cranks are not.....so about the only common thing is they ahve rods and they spin. Quote Link to comment Share on other sites More sharing options...
booxzzy Posted June 28, 2012 Report Share Posted June 28, 2012 (edited) the crank a 4 stroke is a self bathing style......2stroke cranks are not.....so about the only common thing is they ahve rods and they spin. Most of them are self bathing but Yfz450r has dry sump way of lubrication. You are telling me all I already know,I still cant see the point of arguing about this with you because I see u know "few" things about engines but I know few things too. Btw I newer said they are the same,i just said they are simillar,they have the same moving parts and they have the same function and thats about it. Why are you making sudha big deal from it? Edited June 28, 2012 by booxzzy Quote Link to comment Share on other sites More sharing options...
Jereme6655 Posted June 28, 2012 Report Share Posted June 28, 2012 jpointing some things out as it was already said they were two completely different setups.....and then it was claimed that they are two similar setups. not trying to make a huge arguement out of it with you... Quote Link to comment Share on other sites More sharing options...
sredish Posted June 28, 2012 Author Report Share Posted June 28, 2012 (edited) anybody have any comments about what I'm talking about... i could give a shit about the differences between a yfz and a fuckin banshee...... booxzzy, i understand you're trying to help, no probs. Edited June 28, 2012 by sredish Quote Link to comment Share on other sites More sharing options...
Jereme6655 Posted June 28, 2012 Report Share Posted June 28, 2012 man.....that is an odd one....it almost does look like bearing munched itself....but you say it all feels tight. how hard do you have to jack around on it to get it to clunk.....wonder if your flywheel nut came off and its your flywheel free wheeling on the cranks tapered shaft. either that or its got to be a bearing.... Quote Link to comment Share on other sites More sharing options...
BigRed350x Posted June 28, 2012 Report Share Posted June 28, 2012 Check out the bottom end walkthrough in my signature... The bottom end on these is pretty simple. Quote Link to comment Share on other sites More sharing options...
sredish Posted June 28, 2012 Author Report Share Posted June 28, 2012 (edited) man.....that is an odd one....it almost does look like bearing munched itself....but you say it all feels tight. how hard do you have to jack around on it to get it to clunk.....wonder if your flywheel nut came off and its your flywheel free wheeling on the cranks tapered shaft. either that or its got to be a bearing.... good idea on the flywheel, didn't think about that. i'll pull the cover and see. it had lost some compression so i wanted to look at the top end and with the burn score marks glad I caught it when i did. i'll check the flywheel here in a sec. got to get some parts up for sale. the rods in relation to each other are tight as hell, no play whatsoever. Edited June 28, 2012 by sredish Quote Link to comment Share on other sites More sharing options...
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