papasmurf96 Posted January 18, 2013 Report Share Posted January 18, 2013 ok guys banshee has been running great for about 30-40 hours of riding, the other day I went to ride and the bike has no power at all, i ran a compression test 40 lbs left cylinder 20 lbs right cylinder. i pulled the heads and left cylinder has no apparent issues but right cylinder the whole exhaust side of the piston is tapered(about 1/8 inch flat spot), also on the right side of the case, the crank is visibly rubbing the case. I need some help figuring out what to do i will post pictures tomorrow. mods are pro-design coolhead,21cc domes, nology coil hotwires, dynatek cdi (adjustable running stock curve), k&n pods with pre filter, pro x pistons (.80) over, standard replacement crank, bearings, seals, gaskets, b8es plugs, aluminum radiator with high flo impeller, 32:1 yamalube synthetic, 93 pump gas, pro circuit pipes, pro circuit silencers. I really would appreciate any advice or info on this, thank yall. Quote Link to comment Share on other sites More sharing options...
Finch Posted January 18, 2013 Report Share Posted January 18, 2013 ever get the crank welded? id split the cases and see what the crank looks like Quote Link to comment Share on other sites More sharing options...
papasmurf96 Posted January 18, 2013 Author Report Share Posted January 18, 2013 no, the crank was not welded but tomorrow when its not freezing im going to split the case and check things out Quote Link to comment Share on other sites More sharing options...
papasmurf96 Posted January 18, 2013 Author Report Share Posted January 18, 2013 at what compression should the crank be welded or should i just go ahead and have it welded as it is a new hot rods crank Quote Link to comment Share on other sites More sharing options...
Finch Posted January 18, 2013 Report Share Posted January 18, 2013 i had around 130 and my crank started to let go. they can let go on any motor better to have extra insurance but being a hot rods it should of somewhat of a weld but there not that good from what i hear i had mine welded just to be safe Quote Link to comment Share on other sites More sharing options...
papasmurf96 Posted January 18, 2013 Author Report Share Posted January 18, 2013 alright who makes a nice reasonably prices crank? Quote Link to comment Share on other sites More sharing options...
Jereme6655 Posted January 18, 2013 Report Share Posted January 18, 2013 hot rods. that's about the most common crank your going to find on here. they're not bad.....about the same as the so called better cranks. Also there is not a specific compression number that they should be welded at........best rule with the cranks is just to get em welded. How long did the bike sit between when it was running great and now? Im wondering if you had stuck rings. Also you said one piston is flat on the exhaust side......who did you have do the last bore/hone job.....I bet they didn't chamfer your ports causing one of your rings to snag the sharp exhaust port and start the damage. Can I ask why your motor is up at .080 bore right now? If you had that done in the interest of gaining size to get "more power".......then you screwed yourself.... .080 is the most these things can safely be bore out to......so if those jugs need to be bored, which im guessing they do based on them not running now, then your lookin at having to get new cylinders. 4 stroke motors can accomplish more power by being bored larger.......2 strokes don't see any power difference from boring to the maximum size and also......you shouldn't waste those valuable bores for the search of power. Quote Link to comment Share on other sites More sharing options...
bansheesandrider Posted January 18, 2013 Report Share Posted January 18, 2013 at what compression should the crank be welded or should i just go ahead and have it welded as it is a new hot rods crank My crank spread on a stock motor that just had a set of pipes. I now do it on every motor as soon as I get it. Quote Link to comment Share on other sites More sharing options...
papasmurf96 Posted January 18, 2013 Author Report Share Posted January 18, 2013 the jugs are at .80 because when i bought the bike the previous owner had run it lean on the left cylinder and scarred the wall and they were already at .60, so next size was .80 I do understand that larger bores do not give you any gain at all, the bore/hone job was done by zabors in austin and all ports were chamfered, i made sure this was written on the service memo, as well as done when i picked them up. bike sat about two weeks between running great and barely running Another thing i forgot to mention, after i went for a ride and noticed it would not rev out i pulled the plugs and the right cylinder plug gap was completely closed? i always gap at .030, and the plug was not dropped or tapped on when going in. also the rings are not sharp or anything like when they went in they are extremely shiny and almost rounded not sure if that means a stuck ring or not. when i get home today from work im going to split the case and check things out Quote Link to comment Share on other sites More sharing options...
papasmurf96 Posted January 18, 2013 Author Report Share Posted January 18, 2013 here are some pictures i took this morning Quote Link to comment Share on other sites More sharing options...
papasmurf96 Posted January 18, 2013 Author Report Share Posted January 18, 2013 Quote Link to comment Share on other sites More sharing options...
papasmurf96 Posted January 18, 2013 Author Report Share Posted January 18, 2013 Quote Link to comment Share on other sites More sharing options...
papasmurf96 Posted January 18, 2013 Author Report Share Posted January 18, 2013 left cylinder detonation marks? Quote Link to comment Share on other sites More sharing options...
papasmurf96 Posted January 18, 2013 Author Report Share Posted January 18, 2013 Quote Link to comment Share on other sites More sharing options...
papasmurf96 Posted January 18, 2013 Author Report Share Posted January 18, 2013 chamfering of the cylinders Quote Link to comment Share on other sites More sharing options...
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