Broken anti ventilation plate

I'm looking at buying a late 80's 15 HP Mercury. The only problem I see with it is one side of the anti ventilation plate is broken off. How much will this effect the performance of the motor? Is there a relatively inexpensive fix?

Hi, can you post a picture so I can see how bad it is? Thanks.

How do I do that?

Go to "Advanced" down where you see it in lower right corner here. Then you can click on the attachment (paper clip) up in the area above the message. This will open a window for photos. You can follow guide there and add a photo from your smart phone, but be sure to reduce the photo file size, first. I like to use Lit Photo, get that free install on your smart phone. I reduce mine to about 500K. Are you able to do this you think? My young son showed me how to do it.
If too much of the anti-cavitation plate is missing, you will have to weld one on. I do this type of repair here. It is not expensive for my customers. Do you know someone that does aluminum welding near you? A MIG welder is best for this type of repair.

Nice job on the photo. Needs replacement/repair. Looks like a clean motor. Where are you located? Simple fix for a man with some experience.

Thanks, but it's not actually my photo. I'm way down in northern IL. Is it usable until I do fix it? Will it pull to one side, cause problems running with it as is?

Check the prop shaft to see if bent!!!!!

You can run it, but its not going to perform well. This plate prevents the prop from pulling air and also helps the motor to "lift" and get it on step. If your using it for a slow speed kicker or troller, and it is deep enough into the water, you can get by. I would say check shaft, like Pappy recommends. If prop has been replaced, it could mean a bent shaft. Looks to me like some strange accident caused this damage. If you could get it to Duluth, I could make it like new 4 you but gonna be a couple C notes. Here is a 135 Optimax I rebuilt last fall. It also had a bent shaft. Paint is base/clear automotive epoxy.

Nice work! I appreciate all the feedback, but I think I'm going to pass on this motor. Aside from the broken plate, it looked like a pretty good deal, but I've got time and other options.

Yes, these are the deals that I like to grab, too bad I'm not going to Chicago. My wife is there now, but she will be flying home today. Take care, Wick.