Atlbanshee Posted April 5, 2015 Report Share Posted April 5, 2015 I got new top end domes ,pistons,everything. Motor petty scary a lot of power i love it Did a few passes probably 4 of them and on 5th pass the spark plug broke on my left cylinder And when i open the motor i see like the cylinder melt . Left piston looks really bad and right side is new here some pictures .Can some one tell me why it did this . Sent from my iPhone using Tapatalk Quote Link to comment Share on other sites More sharing options...
Phelps Posted April 5, 2015 Report Share Posted April 5, 2015 You didn't leakdown test it or jet it properly and leaned that cylinder out. 1 Quote Link to comment Share on other sites More sharing options...
camp0429 Posted April 5, 2015 Report Share Posted April 5, 2015 That sucks. Few extra minutes woulda prevented that Quote Link to comment Share on other sites More sharing options...
BANSHEE HP Posted April 5, 2015 Report Share Posted April 5, 2015 were these passes back to back? Quote Link to comment Share on other sites More sharing options...
Atlbanshee Posted April 5, 2015 Author Report Share Posted April 5, 2015 No i did like 3 passes first week and two weeks later that when this happen Sent from my iPhone using Tapatalk Quote Link to comment Share on other sites More sharing options...
Atlbanshee Posted April 5, 2015 Author Report Share Posted April 5, 2015 This is the other piston and the domes . What broke was the spark plug lectron. It when in to the piston . I tune the bike really good i don't think was lean but hell i don't even know now. You guy think i can save those cylinders ? Sent from my iPhone using Tapatalk Quote Link to comment Share on other sites More sharing options...
Atlbanshee Posted April 5, 2015 Author Report Share Posted April 5, 2015 Weather was 78*. I have 40mm lectron alky carbs Was set at 1.86 inch measuring with the caliper Sent from my iPhone using Tapatalk Quote Link to comment Share on other sites More sharing options...
Atlbanshee Posted April 5, 2015 Author Report Share Posted April 5, 2015 Here is a video before couple hours before this happen http://youtu.be/p8qribzfMuQ Sent from my iPhone using Tapatalk Quote Link to comment Share on other sites More sharing options...
Strm Trpr Posted April 5, 2015 Report Share Posted April 5, 2015 Like said above, a simple leakdown test would've prevented this. Left side obviously had an intake leak and leaned out or something in the left carb leaned out and burned it down. The piston crown is melted on the exhaust side, signifying high EGT's. Quote Link to comment Share on other sites More sharing options...
Atlbanshee Posted April 5, 2015 Author Report Share Posted April 5, 2015 Thanks strm trpr iwould look into that. What do you thing about cylinders ? Can i still use them if a clean them out? Sent from my iPhone using Tapatalk Quote Link to comment Share on other sites More sharing options...
n2otoofast4u Posted April 5, 2015 Report Share Posted April 5, 2015 So it dropped the porcelain for the piston in the motor, or just melted the strap? I'd agree with what the others have said about it going lean. There's a million variations of why so you will have to diagnose that. Is this strictly a drag bike? If yes, and you can't get the cyld to clean up and stay in spec I'd have just that one cyld bored, new piston, put it together and run it. Yes the bores are missmatched. I'm sure I'll get flamed for this but most on here are to fucking stupid to pour piss out of a boot so I couldn't care less. You can either spend a little time with a cutting tool and remove some material from the bottom side of the new larger piston to get the weights close, or you do what I would do and just put the fucker in and run it. 1 Quote Link to comment Share on other sites More sharing options...
Strm Trpr Posted April 5, 2015 Report Share Posted April 5, 2015 (edited) The left dome is missing an o-ring, unless it fell off before the picture.Check your float height too. I know you're not on stock carbs, but stock float height is 20+/-1mm. Edited April 5, 2015 by Strm Trpr Quote Link to comment Share on other sites More sharing options...
Atlbanshee Posted April 5, 2015 Author Report Share Posted April 5, 2015 Yes fell off before the pic. Float on left side is stuck just notice that Sent from my iPhone using Tapatalk Quote Link to comment Share on other sites More sharing options...
bigweav81 Posted April 5, 2015 Report Share Posted April 5, 2015 What was your current bore? Take them to a machine shop, and they can tell you how far it would take to clean them up. 1 Quote Link to comment Share on other sites More sharing options...
Strm Trpr Posted April 5, 2015 Report Share Posted April 5, 2015 (edited) What was your current bore? Take them to a machine shop, and they can tell you how far it would take to clean them up.I like it!! ^^^Question for n2o, I believe they call you Green, if the OP ends up boring that one cylinder, will he a) have to jet that side differently, and match the mass of the larger piston to that of the lighter piston? Edited April 5, 2015 by Strm Trpr Quote Link to comment Share on other sites More sharing options...
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