Post
by robber57 » Tue Oct 11, 2016 1:39 pm
Rattles i have had so far:
If you dont replace the copper exhaustseal when dis/assambling the exhaust can develop a difficult to locate rattle which may sound like transmission noise.
The air filter box has on top a fixture out of plastic that can wear loose due to vibrations and start rattling.
The mid stand hinges havo no protection and need regular cleaning and grease, if you dont the hinges wear out and the stand rattles at a certain speed.
In the beltcase there is a small bearing, if it wears out you may hear a high pitch grinding when cornering.
And belt-slap, the proof that honda honda designed a vario trying to get transmission losses the lowest and therefore giving the belt absolutly the lowest resistance by keeping some play on the slack-side.
If you tighten a v-belt to the point that under high load it doesnt develop a "slack side" the transmission loss will go skyhigh just like wear and noise.
A v-belt has a "pull side" and a "slack side" , the pull side of the belt is where the tension is when your driving, with the sh the upper part of the belt as it rotates from driven rear vario to front drive vario.
Due to stretching of the belt under load tension the bottom side of the belt --->where no power is transfered<--- hangs loose and accumilates the slack produced by the top that stretches under the load, so with a vbelt under load you may expect to see one side of the belt in a nice straight line or curve and the other side of the belt will be hanging loose and if you suddenly increase or decrease power you will see it flapping on the load changes: when going from acceleration to decelleration you shift the slack side from the top of the drive to the bottom as the load changes from pulling with the engine to pushing the engine with the road.
On a variomatic this is complicated by a torque driver that has to respond to the demand of the front drive vario to keep the belt tension as constant as possible under all load conditions, if the torquedriver cant keep up with the demand of the drive vario the belt wil get some more slack.
This also means that looking at belt tension with a scooter on its midstand just revving it tells you little as there is no load at all and so the torque driver doesnt work well as it needs torque (load) to function.
With idling engine you may notice that both upper and lower part of the belt are slack, that is because the driven variator is at the end of its stroke and the belt is intentionally given an even lower tension to further reduce loss when idling
I would be more concerned if it did not slap/flap at all which is an indication of an over tightent belt.
If it gets excessive it may be caused by a irregular working torque driver, the guide rails and pins can wear out or run dry, cleaning and repack with one teaspoon of nlg3 grease which is really thick stuff, if you the grease is to thin it will run out of the chamber into the clutch, the same goes for overfilling ,if you put to much grease in it will fly out.
Also take look at the big plastic bush/collar and opposite on the big spring, this is a thrust bearing for the spring so the spring can rotate as it crimps-expands, the top surface should be spotless clean and smooth, you can wipe some silicone spray with a towel on the surfaces to improve friction so the spring can rotate smootly as it expands and contracts.
Failure is not an option, it comes bundled with the package.
1000 km's ago, the rattling was there too and the Honda workshop replaced the belt / clutch / bell / torque driver on warranty. Now the rattling is back again. And of course, I have the workshop manual. 
