First Outing on new (to me) Scarab 1 OVERHEATS AT IDLE!!! HELP!!
 

So I took my new to me Scarab 1 out for the first time this past weekend on Lake Lanier here in Georgia.. Brand new mercruiser 350. Boat started right up, as I was idling through the no wake zone which was quite long I happened to look at the temp guage and the engine seemed to be overheating!! 220-230 degrees... As soon as I got out of the no wake zone and planed up the temp dropped to 140 and stayed there no matter what RPM as long as it wasnt at idle. What gives? I did do something stupid when I first bought it. I hooked up the hose but didnt realize that one of the ears wasnt installed properly.. it ran that way for about 3-5 mins before i saw that the water wasnt coming out from where it was supposed to. Could it be the impeller? Circ Pump? Dont want to blow up this new engine already!! HELP!!

You probably fried your impeller and it is only working enough at higher rpm's .... Time for a change !


Jim

thanks for the reassurance jim, changing it today, will report back how she acts.

Thanks!

If that doesnt work, check that the hose between the drive and gimbal isnt kinked.

+1 on both. Had the same thing happen in my Excel over the weekend. Changed Impeller and ran fine.

BTW it's always good habit to make sure the boat is spitting out water while you are still docked, that's how I fould my problem....so I just sat there in the slip, drank some beers, and listened to some music before putting the boat back on the trailer......hey at least I was in the water :)

Thanks for all the replies, going to test my skills changing this impeller, first time I've ever worked on a boat, found some good articles online.. Hope all goes smoothly..

you def burned up the water pump impeller in the bottom of your outdrive...alpha drive i assume? been there, done that, got that tshirt so dont feel bad...its a cheap part and something you want to replace at the start of every season anyway...with no water that rubber burns up fasst...at least you caught it before the temps went to high and you did some major engine damage....good luck with the change out and let us know how it goes...

now my question to everyone else is, would a water pressure gauge have let you know something was wrong in this type of situation...

It would definitely help spot a problem. Watching for a fluctuation in water pressure would indicate an issue. I good steady pressure is what you want to see. Depending on the sea pumps it could be between 10 - 25 psi. I think that is right. If not please correct me.

one of the gauges i am looking at only goes up to 15psi and the other goes to 35psi...so i should def get the 35psi one?