doorslammer Posted July 25, 2007 Report Posted July 25, 2007 hey all well another problem for another day, the left cylinder will idle and rev fine and work a little than it stops ?firing?. it wont run on the same side utill the bike is turned off than started again to whichit will go for a little tan cut out. i have cleaned the carbs and put new spark plugs in to no success. also sometimes when i stop and turn it off there a clunking noise like somthing is falling in the left muffler thanks Quote
joneser4u Posted July 25, 2007 Report Posted July 25, 2007 sounds like you may have broke a skirt off the piston? Quote
jbooker82 Posted July 26, 2007 Report Posted July 26, 2007 try switching the spark plug wires around. If the problem moves over to the other cylinder after doing the switch then your coil is bad. josh Quote
doorslammer Posted July 26, 2007 Author Report Posted July 26, 2007 try switching the spark plug wires around. If the problem moves over to the other cylinder after doing the switch then your coil is bad. josh thanks just tried that and still no success sounds like you may have broke a skirt off the piston? hmmm... any other ideas? really want all posibilities befor i tear my top end apart just an idea but could it be a blocked exhaust? thanks again Quote
joneser4u Posted July 26, 2007 Report Posted July 26, 2007 (edited) thanks just tried that and still no successhmmm... any other ideas? really want all posibilities befor i tear my top end apart just an idea but could it be a blocked exhaust? thanks again Well think of it like this,what could possably pass through the filter then the carbs then reeds make it through the cylinder to clog the exhaust? What you have described sounds exactly what happened to my friends bike,he must of had a jet clog on him at the drags,was running fine then one cylinder droped off,let cool changed plugs ran fine when refired,warmed up and the cylinder fell of again,and you could hear a noise,repeated process ran fine then dropped off again,I finally convinced him to atleast pull his coolhead,right piston looked like a pitbull had been chewing on it for about a month.When we pulled the jug,the skirt of the piston was gone as well.I couldnt believe that cylinder was running at all,ruined his jug(cylinder) there is a trench you could stick your thumb in where we guess pieces of the skirt had circulated back through the cylinder and got between the piston and wall,no way it could be bored out.Now if he had gave up and tore it down when the problem began he might not need a new jug,but there is also the odds that it was fucked when it first started missing?No way of knowing now.As easly as the banshee breaks down,I would definatly pull the head and take a peek. Edited July 26, 2007 by joneser4u Quote
doorslammer Posted July 31, 2007 Author Report Posted July 31, 2007 hey tore it down and the pistons and barrel were perfect, did a compression check before hand and it was 123RHS and 120LHS still havent found the problem any more ideas would be gratly appreciated thanks Quote
dajogejr Posted July 31, 2007 Report Posted July 31, 2007 Check the crank and bearings, and have it trued/welded while you're at it. Just because the barrels "Look" perfect...and the pistons do too...doesn't mean they are. Get them measured properly for clearance. Unless your eyes are good enough to measure .004 to .012... Quote
orangeirocz28 Posted August 2, 2007 Report Posted August 2, 2007 (edited) I lost my left cylinder while riding a few months ago. After letting it sit for a short while, it would run fine for a few minutes and then die again. After about a week of checking stuff, the case seal on the left side had a small crack in it, and was pulling in outside air from the clutch and flywheel case. I called the local Yamaha shop and they said that they had noticed that problem in several Banshees. After replacing that, everything was great. Wasnt very expensive, just kind of a pain gettin the flywheel off. Worth checking. Just my $.02 worth. Edited August 2, 2007 by orangeirocz28 Quote
blowit Posted August 2, 2007 Report Posted August 2, 2007 Check the crank and bearings, and have it trued/welded while you're at it.Just because the barrels "Look" perfect...and the pistons do too...doesn't mean they are. Get them measured properly for clearance. Unless your eyes are good enough to measure .004 to .012... What, you don't have precision vision?? That reminded me that we had an engineer one day that said you cannot even see .001" or something along those lines. We proved him wrong... I would agree though, measuring trumps " it feels pretty good" any day. Sometimes looks can be deceiving. Brandon Quote
dajogejr Posted August 2, 2007 Report Posted August 2, 2007 What, you don't have precision vision?? Sure I do... I can read a micrometer with the best of them... :yelrotflmao: :yelrotflmao: Quote
doorslammer Posted August 2, 2007 Author Report Posted August 2, 2007 (edited) Sure I do...I can read a micrometer with the best of them... :yelrotflmao: :yelrotflmao: wow... unfortunatly i dont cause i cant read them micrometer thingos, only veneers (think thats hows its spelt) thanks for all your help guys Edited August 2, 2007 by doorslammer Quote
FasterThanU90 Posted August 2, 2007 Report Posted August 2, 2007 the coil could still be causing it, coils work off rpm Quote
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.