1998 merc 150 pumping extremely hot water,,please help!!!!

[quantumman29]

its a 1998 mercury 150 efi "nitro series" outboard....<br />when i hook a hose and ear muffs to the lower unit,the water comes out extremely hot,too hot to even touch, i used the boat last week and it idled and ran at low mph just fine, and it pumped water in a nice stream from the tell tale,<br /><br />however,when i tried to get the boat up on plane and the rpms increased,the overheat warning immediately came on and the engine stopped pumping water....<br /><br />i shut the engine down,waited a few minutes,restarted and made it back to the launch very slowly,the engine pumped water all the way back to the dock and it didnt overheat...<br /><br />i had this similar problem last year during a tournament,the boat was fine all day,then the over heat warning came on and i shut the engine down, a few minutes later after i went in reverse then forward to clean the intakes out,the boat ran strong all day......<br /><br />im very concerned about the high temp of the water being pumped thru the engine even with a garden hose and ear muffs attached...<br /><br />1) impeller ?<br />2) water pump?<br />3) head gasket problems?<br />4) thermostat problems?<br />5) clogged intake lines?<br /><br />i bought the boat last april,i never replaced anything on it,i used the boat 7 times, according to the dealership,the boat was supposedly in top mechanical condition when purchased, engine only has maybe 7 hours use since i purchased it...<br /><br />any help or advice would be greatly appreciated,i just ordered a repair manual and im pretty good with tools.....<br /><br /> thanx,<br /> mike

 

[KCLOST]

Re: 1998 merc 150 pumping extremely hot water,,please help!!!!

Q,<br /><br />I think you just need a new pump kit, but I'll run through the gammit....<br /><br />First, you need to pull the lower unit, and inspect the pump.. When you do, replace the impeller and housing, gaskets just to make sure... It's hard telling when the last time this was done, so do it and you'll know...<br /><br />Second, check the pickup tube for obstruction, and the seal possibly missing (if your motor requires one).<br />Give us your serial# and I'll check that for you...<br /><br />Third, replace the t-stats, same reason as the water pump..<br /><br />Forth, you really need to check the poppet (pressure relief) valve. It is on the starboard side of the powerhead, down low underneath the switchboxes... This must open at higher rpms to relieve excess pressure and water circulating around the block... If it's clogged with debri, it will cause a slow down of water circulation and lead to overheat. If it's stuck open it will cause water to be dumped out of the block prematurely at lower rpms and can cause an overheat condition at idle or cruising speeds...<br /><br />You should really start there...<br /><br />You can also check the compression on each cylinder... Make sure each is fairly equal. If one is more than 10psi off from the others, you could have water intrusion...<br /><br />These are all easy checks, I recommend you do first.<br /><br />Also, if you're a tournament fisherman, don't follow closely directly behind another boat. I've heard with black max motors that air being sucked into the intakes can be enough to cause an overheat condition, even with everything working properly... I'm not saying you were, but I had to blurt that out.<br />Do you have a water pressure guage? If not, I'd get one, they are very easy to install. Will always tell you how the pump is working at any speed, tilt angle, etc. We can help you with that, if you decide to...

 

[quantumman29]

Re: 1998 merc 150 pumping extremely hot water,,please help!!!!

thanx a million "KC",<br />i have very little knowledge about outboards other then how to put gas,oil,plugs,batteries,electronics,and basically anything that dosent deal with the engine internaly....<br /><br />i just ordered a repair manual for the engine from seloc,i understand their manuals are very very good....i am quite mechanically fit so im not too scared to tackle this problem on my own,and luckily i have a pretty good marine repair shop located 3 miles from my home just in case i screw up enough to throw in the towel..<br /><br />im not using the boat much this year as ive taken the year off from the torny trail due to a illness and the fact im movin to florida near the beginning of october and basicaly concentrated on workin instead of playing this summer,hee heee...so i have plenty of time to repair it and i have a nice salt water bay with a great boat ramp 2 miles from my home where i can test run the girl once shes fixed up...<br /><br />so you think its the pump huh? i was investigating around the engine today and ive removed 3 plugs,i noticed they were all quite oily near the threads,i use ngk plugs which do not need to be gapped..is this normal to be oily?<br />now i havent run the boat since it was winterized other then for about 15 minutes in the driveway and 25 minutes last week in the bay,and they are still the same plugs from winterization,i used alot of fogging oil so this may be the oil i see on the plugs..<br /><br />i also removed one of the thermostats,it appeared to be original part....matter of fact,the bolts were plainly never touched by a wrench,they had no scratch marks on them at all,now they do..lol<br /><br />i looked at the lower unit bolts too,they look like they have never been touched either...<br /><br />my speedometer dosent work,i tried to clean the little triangle port i seen nothing in there,i disconnected the hose,blew air in the one end towards the speedo,the speedo moved,blew air in the other hose towards the intake port,it is definetly clogged bad,no air can even get thru,once the l/u is off,can i repair this easily too?<br /><br />well im not gonna do much until i get my manual,once i do,i will inform you all of everything i do and the results,and maybe,just maybe,i'll soon be posting a for sale ad on here,,lmao!<br /><br /> mike

 

[quantumman29]

Re: 1998 merc 150 pumping extremely hot water,,please help!!!!

one more thing kc,<br />the boat is equipted with a water pressure gauge in the dash,it dosent work and id like to get it fixed,if you folks can guide me along in the repair of that,id be more then happy,<br /><br /> mike

 

[KCLOST]

Re: 1998 merc 150 pumping extremely hot water,,please help!!!!

The plugs on my engine have some oil on them also. It's usually black oil (similar in consistency to 2cycle oil) that collects near the bottom edge of the plug). I see that on every plug... If the plug is clean (no black coloration or no oil). That can mean water has gotten into that cylinder.<br /><br />Once you remove the lower unit you can have closer access to the pressure line going to the skeg. I can't remember if you can easily disconnect the line itself from the lower unit or not. But if you can that will even make it easier to clean. If you can find some long pieces of pipe cleaner (or something similar) try running it though there to dislodge any debri). A lot of people use a straightened out fish hook to insert through the intake hole to try to clean stuff out.<br /><br />Make sure the water pressure guage is hooked up to a pressure line. I would imagine that your water pressure line is mounted at the top of the block, behind the flywheel. If you have one you can disconnect the line there, and at the guage, It should be one direct connection from one to the other with no kinks. Make sure it's checked and cleaned out. Test the guage similar to the way you tested the speedo.... If water got into the guage it could be beyond help.<br /><br />Let us know..Good luck.

 

[phatmanmike]

Re: 1998 merc 150 pumping extremely hot water,,please help!!!!

i had same problem with my merc 115hp, pee stream was soo hot it burned you instantly and motor was hot to touch...<br /><br />i took motor apart and found 4 ounces of sand in side of the motor, just were the water enters the cooling area... i removed the sane and now have a clean cool motor...<br /><br />try taking off the lower unit and attatching garden hose to the intake line and turn on hose for a while with engine off so it can rinse out anything that may be in there without running and ruining the motor. while you have it off, replace your water pump

 

[gss036]

Re: 1998 merc 150 pumping extremely hot water,,please help!!!!

Speaking of garden hoses, disconnect your pee tube hose, (with the motor off of course) and hook the hose up to the tube and back flush that way also, has a tendany to flush anything from the poppet valve, but your problem really sounds an old hardend impeller and is slipping at higher speeds and not moving water.

 

[michaelbr1]

Re: 1998 merc 150 pumping extremely hot water,,please help!!!!

Beware of how the gaskets for the water pump housing go on. They are suposed to go a curtain way (the correct one between the metal plate and lower unit; the correct one between the metal plate - on top - and the water pump housing). These two gaskets look closely alike and can easily be confused. If you get their positions reversed, the impeller will tare the gasket and loose pieces will go who knows where - in the engine. <br /><br />Also, be sure to put the metal plate on correctly. If you put it on upside down, it will chew up your impeller and guess what you'll get to do then. <br /><br />You'll probably find that the previous responses to your message will correct your problem.

 

[quantumman29]

Re: 1998 merc 150 pumping extremely hot water,,please help!!!!

thanx everyone for all the responses,<br />id also like to take the time to introduce myself,i just jumped onto the board and immediately began asking questions which was rather rude.....<br /><br />my name is mike,im from staten island new york (originally from central joysey), i am quite good with automotive paint finishing and basic auto repair jobs,(nothing huge like trannies,or internal engine repairs) i own a paving maintenance company ( paving,line striping,seal coating,concrete sealing) and ive been fishing the bfl,flw,and some b.a.s.s tournaments part time since 1996, im selling my home in staten island a.s.a.p and heading south to florida...<br /><br />once in florida i will do more torny fishing and less work( if i can hire enough "good" employees)<br />im 40 yrs old and been doing my business since i was 21 yrs old, im getting quite old and my body feels every bit of my age all though i dont look a day over 39,,lmao......<br /><br />like i mentioned in my previous post,i shall wait until my manual arrives and then prepare myself to tackle the job at hand,after reviewing the manual and determining if its a job i can handle,i will give it a go, my bass boats are my investments, id rather have a qualifies tech work on them for the money it may cost before i go and create more problems then needed,<br /><br />im not afraid to admitt to defeat but i will almost always give something a try if i feel i can handle the task,once the manual gets here and i read the manual alongside the engine,this is when the decision shall be made....<br /><br />once again thank you all for helping me and i shall contribute everything i can to help this board remain a very nice site for all to learn,<br />if anyone ever needs any information on bass fishing,lakes,rivers,im the one to ask,ive pretty much been to most every popular lake,river,and impoundment in the country while on tour......<br /><br />i do have a web site if anyone would like to learn more on bass fishing,and techniques...<br /><br /> http://www.realbass.com <br /><br />enjoy the site,,,<br /><br /> mike

 

[KCLOST]

Re: 1998 merc 150 pumping extremely hot water,,please help!!!!

We will be happy to help you with the motor/boat in any way we can...<br /><br />Take the easy stuff first... It's simply a process of elimination...<br /><br />Water pump,<br />T-stats<br />Poppet valve<br />Flush the water passages (if necessary)<br />Check compression<br /><br />And come up to KC and we'll win the mid-states tournament. And a New fully rigged Nitro...<br /><br />Layton

 

[quantumman29]

Re: 1998 merc 150 pumping extremely hot water,,please help!!!!

when is the torny? is it a team event? ive fished table rock a few times ,bull shoals,and a few others in the mid west,came in 6th place out of 156 on table rock in the bfl championships,<br />i drew charlie ingrams as a partner for day 1 and larry nixon for day 2 in 1997 to claim 3rd place overall in the legends tournament on table rock...<br /><br />im from the northleast ova hee and i do much much better in the mid west and southern torny trails,i guess its the freezing my butt off in mid july and august on lake champlain,1000 islands,lake ontario,and the hudson river that keeps me out of decent place finishes up here..<br /><br />im always down for a tournament as long as i have enough notice to prepare,ive taken this whole year off from the trails to prepare for the move to florida....im actually looking at a tournament on oneida lake for mid august for with the nj b.a.s.s federation trail, im goin nuts not doin tornies,im lost!!!!!!<br /><br />as for the nitro, i shall wait for the repair manual before i start rippin her open,i can still use the stratos if i find it too depressing not doin tornies.....<br /><br />i will begin eliminating this and that once the manual gets here,im fairly convinced its the impeller and the water pump,and i will replace the t-stats as well just to be safe,im sure none of the cooling parts have ever been replaced on her...<br />i also want to get the water pressure gauge workin along with the speedo....and then replace all the electronics...and do some body work on her and re-paint her with about 10 coats of laquer and 6 clear coats,the boat is almost in mint condition now,soon it will be!!!!<br /><br /> mike

 

[phatmanmike]

Re: 1998 merc 150 pumping extremely hot water,,please help!!!!

mike i am mike and live in florida, have for 30 years, and i am 30 years old..... if you have any questions, email me and ill sen dyou info from the local sources for your move or anything.....<br /><br />about the motor, yes, wait till you get the manual.. its the best 30 bucks youll ever spend... i flushed mine with a garden hose and now i can hold my hands under the stream wich is warm and no where near as hot as it was, at higher rpm's it actually shot steam out the pee hole<br /><br /><br />this board has helped me a million<br />and now i will help you!!!!! thats how it works! <br /><br />m ikey

 

[quantumman29]

Re: 1998 merc 150 pumping extremely hot water,,please help!!!!

thanx mike,<br />nice to get to know you and all the others....<br /> mike