Hi, my name is Chad, and I'm new to the offshore boats. I just bought a 1978 Scarab 300. My previous boat was a 1977 Caribbean 26' daycruiser. I am selling the Caribbean, and had a guy come over to look at it. He asked me to fire it up, so I did. He then freaked out because I started it dry, and was convinced the 3 seconds it ran destroyed the impeller. I've never heard of this. I've dry started that boat hundreds of times, usually only for a few seconds, and never had a problem. Is what he is saying correct, and I indeed have damaged the impeller, or is he full of crap? The guy was so upset by it, he got in his car, and drove off. Also, am I correct in assuming the impeller is cheap, and an easy replacement, as I have heard of people replacing them every season for good measure. Any help is appreciated. I am looking through this site all day, to get all the info I can. I really enjoyed the picture thread of the old school offshore. The new stuff does nothing for me.

Well Chad, You can crank it to fire and immediately shut it off. I do it on occasion but it really isn't good practice. For someone who doesn't work on boats to witness that was left with the impression you didn't know what your doing, I may have thought the same thing too. It is good practice to change the impeller every season, much is at stake. Seems to me the real lesson here is to show the buyers how good of care you took of it, take the time to get the hose to demonstrate how well it runs next time.
Jim

On mercury motors I have had you can easily damage the impellor with a dry start, especially an older impellor. I always popped the belt off the sea water pump before starting...problem solved. On my 525's I have never had to replace one but on a previous 454Mag I had to replace the housing (plastic and usually breaks also) and the impellor. I think it cost 150.00 or so in parts.

If a seller does that then I'm going to assume he does alot of other things that aren't "proper" with the boat......I'm done with the boat!!! (and I do all my own work on the boat. I change the impeller (and housing) every year as part of regualr annual service.)

I see. Seems that indeed it was my error. I would like to replace the impellers on my Scarab with TRS drives, is there a thread I can reference that tells me how, or is it a pretty easy job, that could be easily explained? Again, I appreciate the input, and excuse my ignorance as I learn about our motorsport.

here's a great thread read it.

http://www.teambajamarine.com/forum/...ead.php?t=6560

Hello, I would recommend 2 things 1 a sea strainer and a BLUE impeller, We used Sea strainers on the Scarabs not only
to collect junk that would go into the motor but also because
they retain some water so that they prelube the impeller when
you are 'air borne' its a SCARAB thing
Mike J.

but surely if you were to start the boat in the water for less than 3 seconds, water couldnt make it to the impeller that fast. I dry start mine on the trailer EACH and EVERY time on all the boats Ive owned.. im not the guy that waits til it hits the water on the trailer to see if itll start.. Ive never had an issue but I also dont RUN it on the trailer, just get it to fire up and shut her down.. I change impellers every other oil change.. cheap insurance..

You trust your equipment that little that you feel you have to do this? Why?

OK, I read the thread on the Baja forum. Now I'm more confused, as the Caribbean doesn't even have a sea pump. I thought he was referring to an impeller in the outdrive or something. Again, please excuse my ignorance, but what does this pump do? Doesn't the engine waterpump provide enough water, or does this smaller pump kind of "prime" the system?