....it's an MK Endura 40 that I bought after Xmas. It has a small chip in one blade approximately the size of half a dime. Would this be enough to cause it to vibrate?

Are there aftermarket props that offer higher speed?

I have not found any for MK so I thought I would ask here.

A chip that big out the blade will do it. I don't know of higher speed prop's though. :-/

I would pull off the prop and see if the drive pin is bent.  I think that would be the more likely cause.  

any damage to the prop will cause vibration..

as for a "high speed Prop"? Its a 40# you not talking fast.

A solid aluminum prop is available here:

http://www.youngprops.com/

You're going to get nicks the size of half a dime in a trolling motor prop if you are taking your boat into wood.  I've never perceived this type of vibration as an annoyance.  When the vibration is enough to be annoying it is usually a bigger nick than this size or something is jacked up in the shaft or drive pin.  Drive pins are cheap and easy to replace.  (Cheaper than a prop.)  If you hit something that caused a nick it could bend your drive pin as well.  Below is an example of a drive pin kit for $10.99.  

http://www.minnkotamotors.com/products/accessories/detail.asp?pg=propnutkit

If your intent is to replace the prop with a better one anyway, you can check the drive pin while replacing the prop.

MK has some props they call power props available for some of their models on their prop page.  I have no idea if they do anything to help your top end speed over a weedless wedge prop or not.  They claim they do.

I will check the drive pin first.

As far as speed, I have a light boat and the TM is 75% primary power at full speed and 25% trolling. I should probably just use it as is.  

I tried the power prop for Minn Kota. I didn't notice a difference. I wouldn't spend the money.

The Drive pin kits are nice and it is a simple fix, I carry one on my boat (prop too) after having a fishing weekend shortened due to an overzealous fishing partner.

I went to Gander last night and bought the pin kit and a Weedeater II or whatever the special prop is for my Endura, mine had the Powerprop mentioned above.

I pulled the prop and the pin was slightly bent and the recess in the prop that the pin fits in was cracked on both sides.

My new prop and pin worked fine until I heat a stump and now it's vibrating again...30.00 bucks for nothing  :-/

Dude, what a bummer!!    Fishing heavy timber is tough sometimes.  All I can say is slow it down when the timber is thick.  You never know when you'll find a stump or stickup lurking two or three feet below the surface in stained water.

Ouch... in the past week have you...

A. Had a black cat run across your path?

B. Walked under a ladder?

C. Broken a mirror?

I have a small MK that vibrates like that and its the drive pin.

FisherDave

Are there aftermarket props that offer higher speed?

I found this site posted on another thread.

http://www.kipawapropellers.com/index.html