knocking sound from take off

2006 Silver Wing with 2000 km's bought used. I've noticed knocking noise coming from the left rear of the bike on take off from a stop. Only lasts for a couple of seconds and stops as soon as I get moving a few feet. I don't notice it otherwise even at really slow speeds (<10 kph). is this normal, is it more likely to be the variator than the engine

The Silverwing usually makes a rumbling noise upon take-off. If you take off slowly, you will also build up a squealing noise from the belt and clutch. Hard take-offs help prevent this (and are a lot more fun).

The rumbling can be stopped by using lighter variator weights, Dr Pulley sliders or a aftermarket variator (which usually has lighter weights).

Most Silverwings are pretty trouble-free. The chance that you got a lemon is pretty small. Relax and ride.

Curious here as I am having the same issue, what will lighter weights to the top end performance of the bike? And is the noise really hurting anything?

Probably the belt hitting the aluminum case, due to slack between pulleys.
It happens on some scoots and not others.
To verify if this is the problem , open the case and look for rubbing on the lower case.

It won't hurt just annoying.
As the scoot gets mopre miles on it , it will dissipate somewhat.

Mine went away with the J Costa variator, others use slider weights, the stock weight is 28 grams. I will let others tell of experience with lighter weights.

MaxB

Totally misled by the title!!!! Damm!!!

I was going to be smart and say it will be the undercarriage retracting into the fuselage.

You don't have retractable out riggers on your 'Wing' perchance?

MaxB wrote:

Probably the belt hitting the aluminum case, due to slack between pulleys.

If it is the belt slapping, then take off the aluminum case and clean the top and bottom near the front pulley and apply some silicone (or similar) type spray ... it may help to reduce the slap.

x

bigbird wrote:

I'd think twice about putting any silicone spray anywhere near the belt or pulleys. The CVT relies on the friction between the belt and the pulleys to engage.

As I recall the belt slap marks are on the outside aluminum casing which can be moved far away from the belt and pulleys and sprayed.

I have 34,000 miles on my non-OEM belt, so I will be replacing the belt. I will recheck the position of the belt slap marks.

x

bigbird wrote:

honda_silver wrote:

As I recall the belt slap marks are on the outside aluminum casing which can be moved far away from the belt and pulleys and sprayed.

If the belt is slapping the casing and there's silicone on the casing, will silicone not be transferred to the belt?

People have been applying silicone spray to Dr Pulley sliders with no problems ... including me. After it dries you can wipe and there was no residue left.

x

Thanks for all the input. I'm certainly not panicked about this. It seems to occur when the SW has warmed up a bit. Definiteley a hollow knocking sound only at the slowest speeds for a second or 2 while taking off from a standing start. When I have time, I'll remove the case cover and take a look.

Chris