Banchetta Posted May 27, 2004 Report Share Posted May 27, 2004 The skirt broke from the pieces on top of the pistons melting down the sides and creating clearence issues....It definately got hot, but only one side..Looks like you had an air leak of some sort. Doesn't look like detonation to me...more of a lean condition or maybe even lack of oil..... Quote Link to comment Share on other sites More sharing options...
fixitrod Posted May 27, 2004 Report Share Posted May 27, 2004 Here is a piston diagnostic guide by eric gorr http://eric-gorr.com/tech/pistonguide.html Quote Link to comment Share on other sites More sharing options...
Justintoxicated Posted May 27, 2004 Report Share Posted May 27, 2004 yea maybe not coolant leak or detonation, I was jsut listing things off the top of my head. something was definately not right. What kind of piston was it? Quote Link to comment Share on other sites More sharing options...
MULLET~BOY Posted May 27, 2004 Report Share Posted May 27, 2004 once again i will say this they crown of the pistion and the head look like that becouse metal was being smashed up there at 8,000 rpms the detonation would have been more in the center of the pistion if it was lean or a air leak it would have left a nasty little hole in the top of the pistions most likly what happend in this case was eather you have shitty luck and got a faulty pistions or the bore was bad crooked or lose somthing along the lines of that Quote Link to comment Share on other sites More sharing options...
mskarl Posted May 28, 2004 Author Report Share Posted May 28, 2004 As for the head, you could sand down the high areas and reuse it, but I would'nt because this can lead to small hot spots and can cause detonation in marginal situations. You can get a new one on ebay for next to nothing. In fact, I have one I would let go pretty cheep if you need it.As for why it is hard to turn over, I would bet that you have some babit in the crank bearings. You need to split the case and check out the bearings really close. This answers you question about pulling the side off, yes you have to. I doubt that you had coolant in the cylinder, if so we would be able to see some sign of it on the top of the piston. I also don't thint that you were jetted lean, as the head looks really good on the other side. Now having said that, you can be lean on only one side if you have a problem with one carb and not the other. However, as both plugs look pretty much the same, I don't think that is your problem. As for detonation, that is also unlikly as it effects both side in most cases. I think that you either had an air leak or you got a bad piston that did not respond well to you getting the bike hot, or your bore was cut too big giving you execess clearance leading to piston slap. Because the motor is already apart, it is too late to check for an air leak so I would not worry about that until you put it back together. You can measure the bore if you have the correct tools, or get it measured at a shop if you do not. However, I would not take it to the place that cut it to get it meausred. As for a bad piston, that is pretty much a guessing game. Sometimes you can tell by looking at the break and sometimes not. It might help it we know what kind of pistons you had in there. Also, I would like to know if you tightned the base gasket nuts on each cylinder before you torqued the head on you last rebuild. Did you use any type of sealant on the head gasket? how much do you want for the head??? that would be cool to get then I want to see this damn thing due to all of the problems!!! Quote Link to comment Share on other sites More sharing options...
mskarl Posted May 28, 2004 Author Report Share Posted May 28, 2004 I agree you either have some serious clearance issues, or you leaked some coolant and got some hydrolock, especially looking at where it broke. good luck how much do you want for the stock head?? I want to put it back together and sell this damn money pit!!!!! Maybe better luck with another one... Thanks Quote Link to comment Share on other sites More sharing options...
mskarl Posted May 28, 2004 Author Report Share Posted May 28, 2004 As for the head, you could sand down the high areas and reuse it, but I would'nt because this can lead to small hot spots and can cause detonation in marginal situations. You can get a new one on ebay for next to nothing. In fact, I have one I would let go pretty cheep if you need it.As for why it is hard to turn over, I would bet that you have some babit in the crank bearings. You need to split the case and check out the bearings really close. This answers you question about pulling the side off, yes you have to. I doubt that you had coolant in the cylinder, if so we would be able to see some sign of it on the top of the piston. I also don't thint that you were jetted lean, as the head looks really good on the other side. Now having said that, you can be lean on only one side if you have a problem with one carb and not the other. However, as both plugs look pretty much the same, I don't think that is your problem. As for detonation, that is also unlikly as it effects both side in most cases. I think that you either had an air leak or you got a bad piston that did not respond well to you getting the bike hot, or your bore was cut too big giving you execess clearance leading to piston slap. Because the motor is already apart, it is too late to check for an air leak so I would not worry about that until you put it back together. You can measure the bore if you have the correct tools, or get it measured at a shop if you do not. However, I would not take it to the place that cut it to get it meausred. As for a bad piston, that is pretty much a guessing game. Sometimes you can tell by looking at the break and sometimes not. It might help it we know what kind of pistons you had in there. Also, I would like to know if you tightned the base gasket nuts on each cylinder before you torqued the head on you last rebuild. Did you use any type of sealant on the head gasket? how much do want for the stock head?? I am interested so I put it together and sell it!! Quote Link to comment Share on other sites More sharing options...
Blacksmith Posted May 28, 2004 Report Share Posted May 28, 2004 I need to check my parts box to see exactly what I have, but I think that I could let one go for $10 bucks + shipping. However, where are you at, and what do you want for the bike like it is? Quote Link to comment Share on other sites More sharing options...
mskarl Posted May 28, 2004 Author Report Share Posted May 28, 2004 I need to check my parts box to see exactly what I have, but I think that I could let one go for $10 bucks + shipping. However, where are you at, and what do you want for the bike like it is? My brother said to e-mail him with your information etc for the head at joeyz4261@juno.com We live in Tacoma WA. And I'm not sure what he wants to sell it for. I know he has put a fair amount of money into it. I'm the one with the garrage so we work on it at my place. Ohh how do you do a leak down test? Does anyone know??? Quote Link to comment Share on other sites More sharing options...
mskarl Posted May 28, 2004 Author Report Share Posted May 28, 2004 It had vtec (spell) pistons that were 1 over (I think) again my brother took care of that. And the head was milled 5mm from what I understand. And mistakenly we did not measure the rings before we put the bike together. Quote Link to comment Share on other sites More sharing options...
MULLET~BOY Posted May 28, 2004 Report Share Posted May 28, 2004 It had vtec (spell) pistons that were 1 over (I think) again my brother took care of that. And the head was milled 5mm from what I understand. And mistakenly we did not measure the rings before we put the bike together. i am thinking you mean 5 thousanths Quote Link to comment Share on other sites More sharing options...
mskarl Posted May 28, 2004 Author Report Share Posted May 28, 2004 It had vtec (spell) pistons that were 1 over (I think) again my brother took care of that. And the head was milled 5mm from what I understand. And mistakenly we did not measure the rings before we put the bike together. i am thinking you mean 5 thousanths I'm sure your right. I've never had a head milled so I don't know my brother took care of that. Quote Link to comment Share on other sites More sharing options...
SDD Posted May 28, 2004 Report Share Posted May 28, 2004 MSKarl some piston makers only make 1/2mm oversized pistons. Wiseco makes 1/4mm sized pistons. If a shop bored the cylinders to 1/2mm over which is one over for some shops and you got 1/4mm over pistons you have a stand a good chance of ending up with what you have. You would have to measure the cylinders and pistons out to be sure. Check the other piston for cracks around the intake ports. Did the shop that did the boring have the pistons at the time of the work? They might be liable for the problems even if they deny it. Quote Link to comment Share on other sites More sharing options...
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