new optimax cold froze

[keykev]

my friend just got his motion marine jet boat back from the dealer with 8/10ths hours on a new v6 optimax powerhead. he and i have had boats all our lives and know how to break in a new motor. he boats year round here in ct. on a fresh water river if he can. he had the boat in the water for 20 minutes and it locked up. it restarted after cool down but with a knock. the dealer said it cold froze because the water temp is 37 degrees and when the thermostat opened the block cooled and contracted around the hot and expanded pistons? i am an omc guy and do not know much about mercs but think somethings fishy. he has had the boat for about 8 years and gone thru 4 motors but has used it thru winters before with no problems. hope someone can help. thank you, keykev................

 

[SparkieBoat]

Re: new optimax cold froze

I have never heard of such..but then again there is a lot of things I have never heard of.

 

[nwcove]

Re: new optimax cold froze

the "cold freeze" story sounds like bs. lots of guys run ob's here...in salt water thats 30 degrees f in the dead of winter, with no issues . with that being said......4 motors in 8 years???? did he let the motor warm up before going to wot???

 

[boobie]

Re: new optimax cold froze

I've heard of this happening on liquid cooled snowmobiles.

 

[Faztbullet]

Re: new optimax cold froze

Was it a new or rebuilt powerhead? If new from Merc should not be any problems as its warranty. If it was rebuilt by dealer maybe different issue. If only 1 piston failed it wasn't a cold seize as a whole bank will sieze or scuff if it cold seizes.

 

[keykev]

Re: new optimax cold froze

powerhead was new from merc and is warranteed, however it takes 3 mos. to get one which i don't get either. maybe because it is for a sort of i/o jet drive. were not sure how many pistons seized because it mounted tightly in an aluminum box like a difficult to access i/o. motor was fully warmed up and never run at full thottle as it had less than 1 hour on it. thanks everone for your help,keykev...........

 

[Outsider]

Re: new optimax cold froze

Something missing here. T-stats don't just snap open and dump a mass of water where there was none before ...

 

[Mi duckdown]

Re: new optimax cold froze

Something wrong here. I run my boat outboards breaking ice to open water.???

 

[Faztbullet]

Re: new optimax cold froze

If the original engine had a cylinder fail and the same cylinder failed on the new powerhead, the ignition and injectors need to be looked at.

 

[SparkieBoat]

Re: new optimax cold froze

good point Faz...maybe a clogged injector.

 

[keykev]

Re: new optimax cold froze

the motor was changed becuse the last one would not restart once warmed up. cranked over fine, just no start until cooldown, otherwise ran great. i wish it was an old school motor with single fuel pump and carburated, i could probably fix it for him. i think he really needs to find a new dealer, it seems (at least here in ct. maybe) just like with modern day automobiles it is hard to find a good mechanic that really knows what they are doing. i kind of thought fuel and ignition(lean out) but can not work on those electronics. thanks again every one, keykev................

 

[jerryjerry05]

Re: new optimax cold froze

Contact Mercury.They have a traveling tech that works on stuff like this.They also have a great repair team that can help over the phone.
Oh yea sounds like B.S..J

 

[Silvertip]

Re: new optimax cold froze

If the engine had been running for 20 minutes it did not "cold seize". it would have been fully warmed up and besides, outboards are perfectly capable of running in cold water. oil injection and fuel system issues would be high on the list of causes.

 

[SparkieBoat]

Re: new optimax cold froze

The EPA has forced outboards away from carbs, causing us way too much money and way too much grief..there is absolutely no legitimate reason for this, but they are doing it anyway. the complex nature of EFI motors has just about done away with the shade tree DIYer and made boating a much more costly hobby/sport.