1994 evirnude 200 -- how to flush sand out of the coolant passages?

[suzukidave]

i am hoping this is unrelated to my power issues in the other thread.

what is the best way to flush sand out of the cooling passages of a 1994 evinrude 200?

i bought boat/motor long distance. it arrived with the cowl pee hole blocked with sand and about two inches of sand behind that. i unblocked it. after ten minutes of running under load the pee hole blocked up with sand again.

it pees like a race horse when it is not blocked up.

i have two thoughts

1. run it at low rpms with the peehole attachment removed so the flush hole is opened? seems like the best plan but i am concerned there will be not enough water pressure to cool the motor if i do that.

2. backflush it using the backflush attachment in cowl. if have been afraid to do that so far for fear of where the sand might go so i have used muffs

 

[Bob_VT]

You need to do "surgery" .......... You have thermostats that will clog so remove them......... maybe remove the heads too to get most of the sand out. If it is pumping water from the tell tale and not over-heating I would run it! A back flush could clog things.

 

[suzukidave]

thanks, i had no idea about the t-stats. will remove asap.

 

[Bob_VT]

No no keep the T-stats in but to do a proper back flush they need to be removed