AdrenalineJunky Posted April 28, 2010 Report Share Posted April 28, 2010 Is this too much side to side play for the rod? What causes this and where do I go from here? Quote Link to comment Share on other sites More sharing options...
dajogejr Posted April 28, 2010 Report Share Posted April 28, 2010 Side play clearance spec is .0098 to .0295 in inches. That looks like it's starting to separate... Quote Link to comment Share on other sites More sharing options...
toytech Posted April 28, 2010 Report Share Posted April 28, 2010 Is this too much side to side play for the rod? What causes this and where do I go from here? the bank Quote Link to comment Share on other sites More sharing options...
bansheesandrider Posted April 28, 2010 Report Share Posted April 28, 2010 It looks like too much side play to me. You have 2 choices-rebuild what you have or purchase a new crank. it will cost you about $350 to have it rebuilt with new rod kits and new main bearings and having it trued and welded. A new stock stroke, stock length rod crank will cost you about the same, but it will not be welded. I have Twister Crankshafts do all my crank work and boring also. Quote Link to comment Share on other sites More sharing options...
blowit Posted April 28, 2010 Report Share Posted April 28, 2010 Side play clearance spec is .0098 to .0295 in inches. That looks like it's starting to separate... Agreed. Looks like separation. If the crank is good and you want to keep it, just send it in to be trued/welded. They should press it back together, true it, then weld it up. Problem solved. Rebuilding is not a certainty unless it is inspected and proved bad. True/weld is usually around 100 bucks. Mull Engineering Quote Link to comment Share on other sites More sharing options...
AdrenalineJunky Posted April 28, 2010 Author Report Share Posted April 28, 2010 That's what I was afraid of. Separating? What are the Banshee cranks like a 2 piece design that everything is pressed together? I planned on doing new bearings and seals anyways. So this was a timebomb and good thing I took it apart a? Quote Link to comment Share on other sites More sharing options...
toytech Posted April 28, 2010 Report Share Posted April 28, 2010 Is this too much side to side play for the rod? What causes this and where do I go from here? vito's performance products has a 4mil stroker crank that is trued and welded with the plate and gaskets for 500 bucks, thats what I just bought Quote Link to comment Share on other sites More sharing options...
dajogejr Posted April 28, 2010 Report Share Posted April 28, 2010 vito's performance products has a 4mil stroker crank that is trued and welded with the plate and gaskets for 500 bucks, thats what I just bought You'll also need the cylinders ported to match the stroke for the right performance. Quote Link to comment Share on other sites More sharing options...
AKheathen Posted April 28, 2010 Report Share Posted April 28, 2010 if you are gonna have it built, make sure the flywheel seat is good, or get it resurfaced, too.....usually a loose/improperly seated, or bent flywheel leads to crank separation, from what i've seen. Quote Link to comment Share on other sites More sharing options...
AdrenalineJunky Posted April 28, 2010 Author Report Share Posted April 28, 2010 Hmmmmm, might just have it rebuilt then. When you buy a stroker crank what all needs to be changed? If I have to do much changing I just stick w/ stock. Quote Link to comment Share on other sites More sharing options...
SLORYDER Posted April 28, 2010 Report Share Posted April 28, 2010 Hmmmmm, might just have it rebuilt then. When you buy a stroker crank what all needs to be changed? If I have to do much changing I just stick w/ stock. Yeah my crank did the exact same thing. I've heard of others doing the same-I wonder what could be causing this? I sent mine to HJR I believe it was $75 to fix. Might as well send your jugs toget ported while you're at it. Quote Link to comment Share on other sites More sharing options...
bansheesandrider Posted April 29, 2010 Report Share Posted April 29, 2010 Banshee cranks are actually made from 5 seperate pieces- the center pin, 2 inner wheels that have the rod pins on them and 2 outer wheels that have the outer bearings and the journals to mount the flywheel and primary drive gears on. It is all pressed together and held in place by friction/interference fit.When you start increasing the power of you Banshee, it generates forces that overcome the press fit and the crank starts spreading. Yamaha says that there is only a problem with "modified" bikes and therefore never did anything to rectify it. I lost my crank when the bike had nothing more done to it than pipes and paddles, Yamaha considers paddles a modification. I have never lapped or seated a flywheel and I have never had one come loose. I install it and torque it to factory spec with blue Loctite and it has never come loose.If the crank runout is in spec, the flywheel and crank are not damaged from being run loose, and the flywheel is properly tightened, there should be no problems. If a crank has started spreading, there is no way to see if the thrust washers or crank pins have been damaged without taking it apart for inspection. If it is apart to inspect, you might as well put new rod and main bearing on it. It is far cheaper to rebuild it while it is apart the first time, than it is to repair all the damage after it lets go- it cost me over $700 to fix mine when my crank let go. And that was using a set of takeout pistons and not boring it, I had to be cheap because I was unemployed at the time, so I made sure that everything in the bottom end was in good shape so I could just pull the jugs and do a topend to get every thing in good shape once I went back to work. Quote Link to comment Share on other sites More sharing options...
AdrenalineJunky Posted May 5, 2010 Author Report Share Posted May 5, 2010 So there's a good chance it just needs trued and welded? If i'm gonna spend a crapload to rebuild it i'd rather buy an aftermarket 1. Any input on some ot the cranks I see on ebay from MotorCityATV. See alot of stock cranks that are low hours and ready to run condition, needs no bearings or nothing. Quote Link to comment Share on other sites More sharing options...
bansheesandrider Posted May 6, 2010 Report Share Posted May 6, 2010 (edited) So there's a good chance it just needs trued and welded? If i'm gonna spend a crapload to rebuild it i'd rather buy an aftermarket 1. Any input on some ot the cranks I see on ebay from MotorCityATV. See alot of stock cranks that are low hours and ready to run condition, needs no bearings or nothing. Just because a crank came out of a running bike does not mean it is good. The only way to know what kind of shape a crank is in, is to take it apart and inspect everything. You cannot tell if an assembled crank is good because you cannot see the rod pins to tell if there is any scoring or other damage. The crank pin is the bearing race for the lower rod bearing.I have seen a stock cranks damaged with only ten hours on it. The crank that came out of my father-in-law's bike was already starting to spread, we were taking the crank out to have it trued and welded as soon as it was out of factory warranty. This was a bike ridden by a 70 year old man and was all stock except for paddle tires. He had bought the bike brand new in August 93 at Sandfest and we tore it apart on Thanksgiving weekend 93 to have the crank welded because he had seen what mine looked like when the crank came apart. We were lucky, the crank guys pulled it apart and inspected EVERYTHING, it was all OK, and put it back together and trued and welded it and we never had a problem with it after that. The problem is that once the crank spreads, even minutely, that the rod can wobble and this causes scoring on the crank pin. And that damage cannot be seen without tearing the crank apart. So you should either rebuild your crank properly, buy a rebuilt exchange crank from somebody like Twister Cranshafts, or buy a brand new crank that is trued and welded. I would never buy a used stock crank and drop it it. Edited May 6, 2010 by bansheesandrider Quote Link to comment Share on other sites More sharing options...
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