Mariner Magnum II 150

[louism]

My magnum II 150 was started after about 6 years. Used earmuffs to start. Had lower unit rebuilt and also asked tech to install new pump (impeller). It idles between 1000 to 2000 rpm acording to guage (In neutral). It takes a few minutes before water exits the **** hole and is hot but not burning hot. Is that normal. Do you think I should rebuild carbs.

 

[starcraft1982]

Re: Mariner Magnum II 150

As for water,it will not flow immediately,should be no more than 20-30sec though.While im not familiar w/that particular motor,if it has thermostats,i would first check/test them as t-stats control the flow at idle.Poppet valve takesa over at higher rpms.Dunk those t-stats in hot water(using thermometer to ensure its higher temp than required to open them).As for idle rpms,that is high.being that its sat so long,a good thorough carb cleaning/rebuild is highly recommended.and add fuel pump rebuild kit into the mix as well.

 

[starcraft1982]

Re: Mariner Magnum II 150

just to add.If moneys not super tight,youd probably be better served just to replace the t-stats,again from sitting so long.And,if that doesnt help your issue,you might want to pull off lower unit,just to verify everything was lined up properly during istallation.Good luck

 

[j_martin]

Re: Mariner Magnum II 150

By far the best indication of cooling system performance is a water pressure gauge. That would replace all the advice so far given. T-stats are normal if the tell-tale is hot, not blistering. You can actually put a thermometer in the stream and know the temp. Pressure would tell you if the pump, poppit, and passages were normal without any disassembly.

hope it helps
John

 

[starcraft1982]

Re: Mariner Magnum II 150

Ok,it is my understanding that t-stats control flow of water through the motor at idle.they open/close to maintain proper temp while at idle or slow speeds.After @3000rpms,the poppit will open to allow more water to circulate as more volume of water is needed to continue cooling the motor at higher rpms.So in my response,i was assuming it was at idle,for one.Two,I was assuming it wasnt a restriction as eventually it started flowing.So I have a couple questions.Was the stream good and strong once it did start?Was the motor ran more than once w/same issue,taking a couple minutes to start the flow but starting,eventually?If it did take minutes to start,but did start,on more than one occasion,i would have trouble thinking "obstruction".Personally,I would still be led to sticking t-stats.I know John is a wiz when it comes to mercs so i dont doubt him,but i am always eager to learn and i hope he ll chime again or message me as to how he ruled out t-stats.Im just curious,not doubting.

 

[louism]

Re: Mariner Magnum II 150

By far the best indication of cooling system performance is a water pressure gauge. That would replace all the advice so far given. T-stats are normal if the tell-tale is hot, not blistering. You can actually put a thermometer in the stream and know the temp. Pressure would tell you if the pump, poppit, and passages were normal without any disassembly.

hope it helps
John

Thanks for replies. I do have temp guage as well as psi guage. Problem is that the psi guage is not installed on engine, just on dash. I cant figure out where the tube is installed on the engine.

 

[louism]

Re: Mariner Magnum II 150

Ok,it is my understanding that t-stats control flow of water through the motor at idle.they open/close to maintain proper temp while at idle or slow speeds.After @3000rpms,the poppit will open to allow more water to circulate as more volume of water is needed to continue cooling the motor at higher rpms.So in my response,i was assuming it was at idle,for one.Two,I was assuming it wasnt a restriction as eventually it started flowing.So I have a couple questions.Was the stream good and strong once it did start?Was the motor ran more than once w/same issue,taking a couple minutes to start the flow but starting,eventually?If it did take minutes to start,but did start,on more than one occasion,i would have trouble thinking "obstruction".Personally,I would still be led to sticking t-stats.I know John is a wiz when it comes to mercs so i dont doubt him,but i am always eager to learn and i hope he ll chime again or message me as to how he ruled out t-stats.Im just curious,not doubting.

Yes the motor was run about 4 times with same issue. As far as stream I would say it would shoot about 1 foot before curving downwards. Thank you for replies. I probably will replace stats and rebuild carb/ fuel pump over winter. If you have any advice over the rebuilds,I would appreciate it. Thank you.

 

[j_martin]

Re: Mariner Magnum II 150

Thanks for replies. I do have temp guage as well as psi guage. Problem is that the psi guage is not installed on engine, just on dash. I cant figure out where the tube is installed on the engine.

Top of the block, centered just aft the flywheel is a pipe plug, or a hose going down to the poppet. Either way, that's where the temp gauge hooks in.

hope it helps
John

 

[louism]

Re: Mariner Magnum II 150

Top of the block, centered just aft the flywheel is a pipe plug, or a hose going down to the poppet. Either way, that's where the temp gauge hooks in.

hope it helps
John

Hi John. Sorry for misunderstanding but I have both guages installed on dash. As far as engine side,temp guage is installed but not the psi guage. The tube for psi guage is very thin. The size of a tooth pick with male fitting on it. Is their function the same. Thank you once more.

 

[j_martin]

Re: Mariner Magnum II 150

Hi John. Sorry for misunderstanding but I have both guages installed on dash. As far as engine side,temp guage is installed but not the psi guage. The tube for psi guage is very thin. The size of a tooth pick with male fitting on it. Is their function the same. Thank you once more.

I don't understand your question. The tube for the pressure gauge is very small. If there's a pipe plug in the block, you replace it with a barbed fitting to fit that tube. If there's a control hose going down to the poppet, you put in a T fitting with the branch being the size of that gauge tubing.

At any rate, what the gauge registers as you go up through the RPM range will tell you all about how the various components of the cooling system are working.

hope it helps
john