Bet & Win 150 shudders when accelerating. Clutch issue?

[heypete]

Hi folks,

My 2006 B&W 150 has recently been shuddering when accelerating. It presently has 4996km on the odometer.

When the speed is between 10-15 miles per hour, the scooter shudders for a second or two and the engine sound drops in pitch as if it were suddenly under heavy load. If the speed is below 10mph or above 15mph, there's no shuddering and the scooter accelerates normally. Cruising at speeds outside this range are also fine, with no problems.

There does not appear to be any RPM dependence -- the shuddering occurs when I'm gently accelerating past 10-15mph and when I "floor it".

I'm thinking this might be a clutch issue, but I'm not 100% sure. Any suggestions for how to more conclusively diagnose the issue?

Many thanks!

[Calothrix]

Glazed over clutch pads could be causing your problem.  If so, take some emory paper to them and wipe the clutch bell off with denatured alcohol and you should be good to go.  Worked for me on a similar problem with my P150. 

[Hoolander2]

That sounds like belt slippage too.  Visually check your belt and measure it's dimensions if in doubt.  Also, could slip due to foreign substance such as oil having gotten on the pulleys. 

[heypete]

Hi folks,

One quick question: is the B&W 150 clutch the same as generic GY6 clutches like this one? Visually it looks identical to the B&W 150 one, but getting independent confirmation would be ideal.

I ask because it's likely to be cheaper and easier to simply replace the whole clutch assembly than bother taking the clutch apart to de-glaze the pads and bell.

Thanks!

[Portland Steve]

Have you removed the clutch yet?  You will need an impact wrench or a special clutch tool to get the nut off.
You will not get the nut off without some kind of special or improvised (I tried improvising, not good) tool so BEWARE.
I had some slipping and shuddering with my Super 8.  I cleaned the clutch pads and the bell surfaces to remove any glazing.  It virtually stopped the slipping. 
However, after seeing what a piece of crap the stock clutch is, I am tempted to replace it with a performance piece like the one below:

http://www.scooterpartsplace.com/malossi-maxi-delta-clutch-honda-gy6-125-150.aspx

With that said, I think you should try cleaning your clutch and checking your belt before purchasing a new clutch.

Cheers

[heypete]

Steve: I haven't yet, but I'll give it a shot in the next week or so. I have a reasonably complete tool kit (at least in regards to hand tools; no power tools yet) but can probably acquire an impact wrench without too much trouble. We'll see. Minor problem: I live in the Phoenix area and work in Tucson (I sublet a room from a friend, so I only drive down in my car once a week, then commute to work using the scooter) so the scooter is in Tucson and the tools are in Phoenix. Doh. I'll see if my friend has the appropriate stuff so I can look at the clutch and belt tonight.

I figured the stock clutch isn't all that great, but the performance one is about 1/4th the total resale value of my scooter. Not really worth the money at this point in time. Various Kymco shops have Kymco clutches (at least the parts that wear) for about $60. Since much of the rest of the drivetrain seems to be more or less a GY6, I figured a cheap GY6 clutch might be worth having on hand if needed.

Thanks again for your help. This forum has truly been a wealth of information over the years for a cheap DIYer like myself.

[heypete]

Hi folks,

Quick followup: I attempted to get the clutch (and later the variator) off today, and failed miserably. They're really on there.

Not to be deterred, I did what I thought was the next best thing and hosed the entire transmission compartment down with large amounts of brake cleaner (it cuts through just about any grime with frightening ease), making sure to get the clutch and variator surfaces.

Next, I applied automotive belt dressing to the drive belt to make sure that it wouldn't slip.

Sure enough, the problem has disappeared entirely. There's no longer any slipping or shuddering. Total cost: about $4.

I purchased an extra belt from the local Kymco shop, but replacing the belt would involve removing the variator, which seems to be an enormous hassle. The current belt seems to be in good shape and seems to be within its usable width -- and the manual states that one needn't even inspect the belt until 7000km (I'm at 5000km) -- so I think things should be good for the time being. I'll probably return the extra belt.

[Portland Steve]

The variator and clutch need a special tool to remove.  As I mentioned, I used an impact wrench and it did the job.
Glad you found a reasonable solution.