1990 Bayliner Capri L Drive Overheating ! Please look

[NicknChristy]

ok, i have a 1990 Bayliner capri with a 90hp l drive. it likes to overheat :facepalm: I havnt been able to get it to overheat while on the muffs, i think its because the water pressure is pushing it through enough to cool it down. While its on the muff the weep hole are spuing, there is water pouring out the exhost snout and is pumping water hard out the back. The first thing i checked was the thermostat to see if it was clogged, thats when i found the thermostat was removed. o crap i thought ! i loosened the thermostat cover and fired it up to see if water was getting to the top and it appeared it was. I brought it to the lake and after about 5 min in the water at wot ( 4500 rpm ) the buzzer sounds, i put my hand on the head just to insure it was hot, it was. I brought it in to a boat repair shop after reading the crazy feedback about this set up and the shop told me impeller needed to be replaced by the description i gave them. they called me latter that day and said they realized there was no thermostat, installed on and they cant get it to warm up, i asked how a thermostat would help cool the motor and having no thermostat wouldnt. they told me the thermostat would help to slow the water flow and therfor cool better. I took it straight to the lake and same, 5 min. in it started to overheat. i brought it back they opened it up to replace the impeller and callen me to tell me the impeller housing was shot and couldnt pump the water up the tube to the top of the head. I brought it straight to the lake and same, overheat after 5 min. The shop is also using muffs but said there was great pressure to the head and stat. The shop wants me to bring it back monday but now im worried im not going to get the prob. fixed and theyll charge me over and over. i am machanically inclined and would rather fix the thing myself!
Would something as simple as bad fuel mix cause a prob.? Any help would be great, thanx guys, nick

 

[ben jones]

Re: 1990 Bayliner Capri L Drive Overheating ! Please look

ok, i have a 1990 Bayliner capri with a 90hp l drive. it likes to overheat :facepalm: I havnt been able to get it to overheat while on the muffs, i think its because the water pressure is pushing it through enough to cool it down. While its on the muff the weep hole are spuing, there is water pouring out the exhost snout and is pumping water hard out the back. The first thing i checked was the thermostat to see if it was clogged, thats when i found the thermostat was removed. o crap i thought ! i loosened the thermostat cover and fired it up to see if water was getting to the top and it appeared it was. I brought it to the lake and after about 5 min in the water at wot ( 4500 rpm ) the buzzer sounds, i put my hand on the head just to insure it was hot, it was. I brought it in to a boat repair shop after reading the crazy feedback about this set up and the shop told me impeller needed to be replaced by the description i gave them. they called me latter that day and said they realized there was no thermostat, installed on and they cant get it to warm up, i asked how a thermostat would help cool the motor and having no thermostat wouldnt. they told me the thermostat would help to slow the water flow and therfor cool better. I took it straight to the lake and same, 5 min. in it started to overheat. i brought it back they opened it up to replace the impeller and callen me to tell me the impeller housing was shot and couldnt pump the water up the tube to the top of the head. I brought it straight to the lake and same, overheat after 5 min. The shop is also using muffs but said there was great pressure to the head and stat. The shop wants me to bring it back monday but now im worried im not going to get the prob. fixed and theyll charge me over and over. i am machanically inclined and would rather fix the thing myself!
Would something as simple as bad fuel mix cause a prob.? Any help would be great, thanx guys, nick

First thing the shop yout taking it to needs to find out what the problem ios without charging you any more money. Over heating can be a lot of things. I am the same as you mechanically inclined and i think we both know with no thermostat it will flush cold water straight through keeping it colder than it should be, although therre should be one in there. the problems that some to mind are the intake being constricted, the exhaust being constricted, or an impeller problem. Take apart your exhaust and your port covers and look at the ports to see if they are full of carbon. check all the way down the exhaust tube too. another thing that could be the problem is the temp sender is bad and is going off before it should. take it off and check it with a thermomoter. In all reality these motors are very simple its almost always something small thats being overlooked.

 

[NicknChristy]

Re: 1990 Bayliner Capri L Drive Overheating ! Please look

thank you for the advice !! For the most part everything is nice and clear ! Not even soot. However i double checked the thermostat, when i pulled it out i could see that it had crud and looked old !! kinda weard since it was JUST replaced. It didnt have a temp rating on it so i found online it was rated 130 deg. so i boiled a pot of water and got to 140 deg. and threw it in, it didnt open. i got the water up to 210 deg. and it still didnt open, i took it dow the the local lake and took it for a spin, i did a couple laps and it didnt overheat !! it felt hot but the buzzer never went off. i have some seafoam in it to so hopefully this is what it was.. thanx for looking in