2008 Honda Silverwing acceleration

Acceleration is ok, has good power and runs 70 or 80 if I want to. But, it should sound smooth and feel smooth except as its accelerating I hear a slight grinding and it feels the same way. Its the only way I can describe it. Once I reach speed and set the cruise control, everything is fairly normal. Very annoying as one accelerates a lot. I think something is wrong. I pulled the cover on the belt and it looks new. Got an appointment with the local Honda dealer but they are so busy I have to wait a month. Just looking for possibilities from some of you with a lot of experience with Silverwings.

Sounds to me like belt slap. Whats the belt mileage /age?

I just bought it from a dealer a month ago so I don't know the scooter's past. The dealer did list it as excellent though. I'm not sure I know what belt slap is. The two pulleys are so close together with a heavy belt???

I take any dealers opinion with a grain of salt, the long wait for service ?, most likely don't want to work on it
If you don't have any dealer prep/service records, you don't know how old the belt, fluids, tires, etc. are, when was the cvt cleaned, inspected ??
The belt slapping the internal CVT case is kinda of normal/nature of the beast on a SW600, caused by the long/heavy belt run and engine harmonics, etc., usually felt around 4k rpms when accelerating, IAC the belt slap itself is usually brief, more annoying and hardly damaging. is worse with old belt and/or neglected CVT service.

Can you give us a little more info Dale. At what speeds and revs are you hearing this grinding.

I've been looking up belt slap but I don't know what it sounds like. I bought this scooter from Niehaus Cycle Litchfield Il. It has 11,000 miles on it and in perfect condition. I checked everything from brakes to oil. It only has this kind of a grinding noise during acceleration and thats at all speeds. This morning on the 4 lane, the noise was there until I hit 70 then set the cruise control. Quiet for miles until I slowed down then had to accelerate a little. We have a master mechanic at our local Honda dealer but side by sides are priority right now as they are big bucks. I'll get my turn.

Hi Dale.

Quick question, what happens if you set the cruise control at 50, does it still continue to make this "grinding" noise or go quiet like at 70.

Also, belt slap is caused by the belt being driven while accelerating, as the belt is pulled on the top by the variator as it expands, it can cause excessive slack on the lower part of the belt leaving the variator which slaps the bottom of the belt case, which will leave black belt mark.

Place the Swing on the centre stand and remove the outer belt case, then start the bike and watch what happens as you rev it up, you might also hear what is causing the noise you hear.
It's ok to do this as there's no load on the drive train at this point, also manually try different rev settings and hold for a bit. If the grinding noise vanishes while doing this, it is probably the outer removed cases rear bearing. Just food for thought.

Hope this helps
Be safe, be seen!

Once I set the cruise control at any speed, the Swing goes quiet. Anyhow, thanks for your suggestion. I wasn't sure about running the Swing with no cover. That should tell me a lot. I'll give it a try.

All the years I've been on motorcycles or scooters, I've never heard of belt slap. It was 93 yesterday but a cold front finally came thru and I did what you suggested JohnyC. The bottom of the case was black as was the top towards the back. Rev'd the Swing some and I could see the belt slapping the bottom of the case. The belt looks new more or less. Will a new belt do the same thing or is it something you just have to live with. Already have it back together and heading out for a ride.

Hi Dale.

The trouble with belts is they can "look" ok, but be stretched to hell, only way is to remove and measure, as the Swings new to you I would replace the belt so you know.
The other problem it could be is the driven plate tension spring. You may have read a few articles headed "Malossi White Spring, part of it's job is to keep tension on the belt.



But because of the relative age and mileage I would go for a new belt first.

Hope this helps.

Oh, you didn't say if you were still getting the grinding noise with the cover off?

Be safe, be seen!

I ordered s new belt today. The Honda mechanic, who is every familiar with Silverwings, will put it on. With only 11,000 miles on it, I'd bet its original. The noise was there but I didn't rev it very hard. Thanks for the help.

We have a new belt, what a difference. Just a little bit of vibration with a heavy foot but the mechanic told me "the scooter is 16 years old so nothing to worry about". And again, thanks for the help.

I have a 2022 Kymco AK550. You open up the throttle and its gone. No vibration or much engine noise. The kids who have no fear say the Kymco will do 100 mph in 4.5 seconds. U-tube stuff. Fun scooter.