MarineNYC Posted January 29, 2013 Report Share Posted January 29, 2013 Ok. Bought a used ported head. Sent it to a builder. He cleaned it up and recut the valve seats and installed +1 stainless ferrera valves with dual rate springs all around. The guy that i bought it from used to run it on pump gas. I got it installed with a 12.5:1 pump gas piston and like a idiot never checked the compression. The bike ran hard for a few rides and then. Got to glamis. Ran for a day and then it just died and i lost all compression. The trip was over and i went home. Anyway. When i called the builder of the head found out that he said that the head was a little warped and that he found out that the guy i bought it from used to run race gas and nos through it. So the builder decked the head and never told me. Big fucked up situation all around. So i pulled the plug yesterday and this is what i found. My question is Does this plug look like it was running lean as hell? Im thinking that the decking of the head brought my compression up and in turn i should have been running race fuel. Im lost when it comes to this 4poke and im scared as hell to open this motor up. (Also because im afraid of what ill find). Any advice will be appreciated. Quote Link to comment Share on other sites More sharing options...
n2otoofast4u Posted January 29, 2013 Report Share Posted January 29, 2013 They aren't that bad to open up. A bit intimidating but when you get into it you will find they aren't that bad. Did you do a comp check or how do you know it lost compression? If you did that means it will turn over which is a bonus! Its hard to tell from the pics but the plug top looks speckled from deto but its hard to tell. Its not uncommon if its detoing to have the strap close up like that. Its there fresh "whack" marks or fresh "specs" of aulm on the plug? Quote Link to comment Share on other sites More sharing options...
So Cal Suspension Posted January 29, 2013 Report Share Posted January 29, 2013 It looks like a pretty typical single tiered wrought iron candle sconce. Quote Link to comment Share on other sites More sharing options...
oldskool Posted January 29, 2013 Report Share Posted January 29, 2013 Did you install head on engine? If so you need to adjust valves on your 4 stroke any time you have head off. sounds like exhaust valves are closed Quote Link to comment Share on other sites More sharing options...
camatv Posted January 30, 2013 Report Share Posted January 30, 2013 deto, lost comp means something exploded. take the head off and then remind yourself why you sold your banshee?? Quote Link to comment Share on other sites More sharing options...
WINDYCITYJOHN400 Posted January 30, 2013 Report Share Posted January 30, 2013 It looks like a pretty typical single tiered wrought iron candle sconce. Tell him what he's won Bob....... Quote Link to comment Share on other sites More sharing options...
MarineNYC Posted January 30, 2013 Author Report Share Posted January 30, 2013 I did a compression test and i have like 45 psi. No bueno. Quote Link to comment Share on other sites More sharing options...
sleeper06 Posted January 30, 2013 Report Share Posted January 30, 2013 Not good bro something let loose do a leak down first ,make sure valves are seated,chack lash ,check cam chain for stretch and tensioner 1 Quote Link to comment Share on other sites More sharing options...
BUILDER Posted January 30, 2013 Report Share Posted January 30, 2013 They are not as bad to work on as you think I would yank the head and the cylinder off and see what went wrong. I am guessing you were pushing way to much comp to be running pump gas and there is probably very little left of your piston. Quote Link to comment Share on other sites More sharing options...
n2otoofast4u Posted February 3, 2013 Report Share Posted February 3, 2013 Well? Quote Link to comment Share on other sites More sharing options...
dirtydownunder Posted February 3, 2013 Report Share Posted February 3, 2013 blown head gasket or cracked water way ? looks like its had water through it. Quote Link to comment Share on other sites More sharing options...
booxzzy Posted February 4, 2013 Report Share Posted February 4, 2013 4pokes are almost as easy to work on like 2pokes,just use common sense and a lot of reading,get the service repair manual and then dig into it.i bought yfz450r almost a year ago and on the first ride crankshaft main bearing snapped and stuffed everything up,crankshaft,piston,cases,cylinder.I fixed it myself all tho it was long and painful repair but hey now i can say i know how to fix this shit Quote Link to comment Share on other sites More sharing options...
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