Need help with my Yamaha areox 2004

Hi my names max new to posting need a lot of help I've Just rebuilt my Yamaha areox 50 cc to a 70s with new stage 6 crank but I have a major issue when I thighten the veriator my hole crank locks up I have all the parts in there from pre rebuild on the veriator side I don't have a clue what's locking it up I've even reopened my engine case and re done the crank 2 times but it's just complete mind fking me

 

hmmm, i will think about this and get back to you, possibly there is a washer in the wrong place?

 

I've removed replaced and re ordered everything in every possible way I think I'll take some pictures peace by peace in order

 

hello max

heard about this problem on the Zumas and it was due to the wrong crank fitted.
the aeros looks like the zuma insides to , ie starter clutch is on the inner side behind the variator.

when you have the variator off and the starter flywheel behind it check to see if the splines clear the race bearing for the crank, i would hedge a bet they are inside the bearing a bit ? if so the crank end to end is shorter and thats why your getting the binding. your cranking down that variator but theres nothing to stop it because the splines are inside the bearing and not flush to it

i would be calling the seller and making sure your crank you recieved is for a aerox 2004 and not a shorter version ie a refined version.
the zuma problem was because the crank was from the inner seat to the bearing to the outer end of the crank being 24cm and not the 29 required. crude but simple looks like this -===={ where the shorter was -==={= , the spines sat into the bearing and were not flush so when everything was cranked down tight the flywheel and all mashed up into the crank bearing face.

grab the old crank and measure the variator side length compared to the new stage 6 ( possible the cranks to short and thats you binding problem), if you have fitted it to the instructions on the tin and rebuilt it to the tins instructions but its binding theres a fault some where and i really think its due to the new crank not being the right length end to end.

 

yeah, that seems the logical solution to me, ive never had the problem doing a yamaha crank before and ive done bloody loads in my time, had it on bigger bikes, but thats been from washers in the gearbox.
a shorter crank would make sense. also worth checking the starter thing is sitting all the way down as it should, it easy to get that a bit wrong because of those stupid spring loaded bearing thingys...

 

just so you get the correct measurement.

on the variator side of the crank, measure from where the splines start and the very tip of the crank end.
then do the exact same on the new crank , if there is a difference between the old crank measurement ( what we know is true) to the stage 6 it shows the stage 6 is the incorrect crank thats been sent out for your bike ( possible its a zuma / cygnus crank they both look the exact same aprat from end to end measurement from the spline start to the end point )