Magna VF750 clutch problem

Whenever we get the bike up to about 30 mph we get a sound as if two metal plates are rubbing together. If we pull the clutch in the sound goes away or if the throttle is thrown open it goes away.

We're guessing it's something in the clutch.

Any ideas?

 

From your description it sounds like a bearing is going in the transmission. When you pull the clutch it puts side pressure on the bearing and when you gas it, it puts a pretty good load on the bearing. Maybe I am completely wrong but its an educated guess. The only way you are going to get a sound out of the clutch is if its is slipping. Other than that theres really nothing to make noise. It would slip long before it started rattling.

 

Hmm, we've never had to deal with a transmission before. This should be fun. We have a service manual coming for it in the mail but before we get into all of it what do you mean a bearing? Is that something that is expensive to replace?

 

I've just developed within the last two weeks what I think is a similar sound. I own a '85 VF700S Sabre (25K miles) which has the same engine as this era Magna.

However, I'm not so sure about it being a transmission bearing. Mine sounds like something rubbing like metal plates or a chain against metal. It occurs between 3k-4.5K on the tach in 3rd, 4th and 5th gears. I can't tell if it occurs in 6th as the ambient noise from the wind drowns out most engine noise at that speed.

Like the OP the noise isn't apparent on hard acceleration, but is evident at a steady cruise, mild acceleration, or when decelerating in gear through the above mentioned RPM ranges. And like the original poster the noise isn't as apparent when using the clutch, but I believe this is because when the clutch is engaged the RPMs fall too rapidly through troubled area.

Again I'm not so sure about it being a tranny bearing. My first hunch is that it's a cam-chain issue as these are a known problem on the first Gen. Honda V-4s (the damn chain is a mile long and has two tensioners which can fail). The other thing I thought it could be is perhaps the water-pump it crapping out.

Any additional ideas would be greatly appreciated. Thanks in advance.

Ciao,
Rob

 

We actually figure out our problem. This one sat for 2 years before we got a hold of it. I guess if the clutch plates sit in the same oil for a while they absorb some because of the material the plates are made of. Running it and putting Marvel Mystery Oil in it fixed the problem, apparently the clutch plates cleaned themselves.

Not sure if this will help you but it helped us.