Rear sprocket help!!!

[WizardMaster]

OK, I have the Tomberlin Crossfire 150 R powered by a 2005 Kawasaki EX500D engine and it runs awesome................except for one thing.......It will throw the chain when I power up as if to attempt to spin the tires, otherwise I can run it all day long....... Now I thought it was the chain my friend gave me from his Harley Davidson he changed out years ago.The chain is the KX520 and seems to be just fine and sturdy yet and should have been fine for this test before buying a new chain.
Today I re-adjusted the engine to take up chain slack for another test and as I used the engine/chain adjuster, I rolled the cart forward and back and moved the engine a tad more and did the roll test to see if the chain tightened up too much and I found that at one half turn of the rear sprocket the chain was fairly tight and the other half turn it was a tad loose as if the sprocket was lopsided but about 1/4" and a 1/4" can make a big difference!!!!!! I think I found my problem! When they cut down the original sprocket to make rook to lay the original Ninja sprocket against( because I'm sure it was too narrow for a 520 chain system) they welded the sprocket straight onto the Crossfire sprocket, BUT, NOT CENTERED perfectly!!!!!! Anyone could have done his right. I am glad I found this early on. OK, now I need to try and find a 520 rear sprocket with what appears to be a bolt pattern of 4 X 80mm. Can anyone confirm this measurement and lead me to a rear 520 sprocket that will bolt up to the Crossfire buggies? If I must, I spose I could change the Ninja front drive sprocket to a 16 tooth 530 and get a rear 530 sprocket if that is my only alternative,but I believe the thickness won't allow it on the engine side,but I prefer to stay simple and with 520. Thanks for your help on this. Scott

[WizardMaster]

BTW, I love my new gas tank! 8 gallons!

[WizardMaster]

OK, My rear sprocket is the original Kawasaki Ninja 41 tooth so I wish to stay with 41 or larger. Thanks.

[JERSEYDEVIL]

you wont find one. most bikes and atvs use 520 chain, what i would do is take find a unit that has a good amount of aftermarket sprocket selection, so you'll have a variety. buy the sprocket w/ the teeth you want and take the axle and sprocket to a machine shop tell them you need a made that is hubcentric for the sprocket you bring him to replace that is the thickness of the sprocket (original) that was welded to the sprocket that you want. so this hub will be the same width of the original sprocket w/ the same 80mm bolt holes to bolt to the sprocket and the same center hole that is hubcentric to the axle the other side needs to cut so the new sprocket is hubcentric to this new hub this is important if you want a drive system that will sustain power and not cause ou problems. being hubcentric takes the strees off of the bolts eliminates sprocket movement and if done right like by a machinist will keep things centered all of the time. i did someting similar w/ my joyner when i swapped in the polaris 400. i had a hub made and weld in place of the original to accept polaris sprockets.

[WizardMaster]

Teeth currently are 41/16 and I believe I can go to 47 teeth on the rear sprocket and I believe that would give me more torque at the rear end. Maybe I can search or custom order a new rear axle and find the hub that works with '520 chain sprockets' and have a hub welded up so that the rear sprocket will be in line with the front sprocket. I don't know if the Crossfire's axles are custom made per length etc. but there are a ton of axles out there. Other than buying a new Ninja sprocket and the thinner 'Crossfire' sprocket and taking that to a machine shop and having it put together and HUBCENTRIC is a cool word. Hubcentric is a good thing since most automotive wheels use the same theory to keep the load of the automobile OFF the lug nuts. Thanks for that advice and if you run into an axle supplier for the one that matches the measurements (minus the hub) of the Tomberlin Crossfire150, please let me know. Thanks. Scott

[WizardMaster]

BTW, as you can see, the Crossfire sprockets are hubcentric.