motor wont warm up

alilley

Petty Officer 1st Class
Joined
Jun 7, 2010
Messages
327
this is my first boat but have worked on many motors in the past so here is the story. i have a 3.0 mercruiser with alpha 1 i have not had it on the water yet as i am trying to get some of the little things lined out beforte i do and hope to get that all done this weekend

ok so here is the problem and my questions....i got the motor fired up and running smooth with about a 1500 idle on the muffs. ran her for about 10 - 15 min (give or take i was not exactally watching a clock). when i returned to check a few things on it i noticed that the temp guage was still showing cold as if it what a fresh fire up. i did put my hand on the manifold and it was at least warm how long should it take for this motor to warm up?? what is normal operating temp?? where is the temp sending unit at? will a motor warm up on the muffs?? what about the choke mine when i open it up all the way it leans out and dies. do marine motors stay partily choked all the time or is it cus the motor is not warming up?? any help here would be greatly appreciated and many thanks in advance
 

zbnutcase

Commander
Joined
Sep 19, 2009
Messages
2,055
Re: motor wont warm up

They really need to be under load to warm up fully. And no, they don't stay choked, in fact in 10-15 mins running even on hose, should be fully open. If it dies with choke open, you have carb issues, probably needs rebuilt, especially if the boat has sat unused for 6 months or more.
 

CheeseCutter

Cadet
Joined
Oct 4, 2009
Messages
29
Re: motor wont warm up

Have you cracked open the thermostat housing to see if there is a thermostat installed. I'm amazed at how many people run without a thermostat. Maybe the PO pulled it out.

If it is there, what variety? 140, 160 ?? That will give you a base to judge how warm it should be running.
 

alilley

Petty Officer 1st Class
Joined
Jun 7, 2010
Messages
327
Re: motor wont warm up

i am hoping that i dont have to crack open the thermostate housing cuz i know it dont leak right noe and dont want to take a chance on it leaking but if i have to then i have to. i am hoping that it is somthing that has come loose or unhooked or as i mentioned a bad sending unit or guage

as far as the choke i have a thred titled 3.0 wont idle or somthing like that and it has all details on what has been done on the fuel issues
 
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