mariner 150

[freenergy]

i just purchased a '89 sea ox w/ twin 150hp mariners ser# oc126303. i am a newbie at these monster 2-strokes and any help would be greatly appreciated.<br /> symptom, starts easy, idles rough then begins losing power at about 2000rpm's. when problem first started it would surge, run good, then run bad. the stator did not test within specs on resistance check btween red&blu and rd/wht and blu/wht was somwhere close to 20,000ohms. read on a forum, dont remeber what forum that the values in the book could be wrong? book doesnt spec what the voltages should be at these points anyone know?<br /> also the bias jumper, the white wire that connects both switchboxes seems to have been very hot as the insulation has seperated from the wire, any ideas?<br /> there is also a very small(very small) fuel leak at base of one of the carbs. if this was the problem wouldnt this cause a lean condition. if i pull the plugs they are still wet, leading me to believe its a weak spark. all cylinders appear to be firing the best i can tell with my fisher price timing light.timing appears to be good.<br /> and lastly, the motors have approx. 350 hours on them and was curious how many hours they should last and when should i start replacing parts in the oil injection system, like the plastic drive gear? there seems to be much controversy on here whether to disable oil injection or bypass, so i think i would like to keep it. just dont want to blow a motor to find out it needs servicing.<br /> i apologize for the length of the thread but i've probably spent close to 40 hrs just reading thru forums. and would like to get this motor back up and running with the least amount of pain($$$) as possible. thanx again for any suggestion

 

[andy6374]

Re: mariner 150

Alright you asked alot of stuff and since there are many possibilities you will get a long reply. First and foremost, get yourself a mercury factory manual for your engine(s).<br /><br />-As far as the ignition is concerned, http://rapair.com/support/Portals/0/downloads/TroubleshootingGuide.pdf <br />This is a great trouble shooting guide for OEM and CDI/Rapair ignition components.<br /><br />-Get a spark gap tester and make sure all coils can cross a 7/16" gap. It should be snappy and blue. If you have OEM ignition components don't be surprised if some have failed, switchboxes first and the stator second. You may or may not have a weak spark (the spark gap tester will eculidate this), if you can't get above 2000rpms you plugs will sort of look wet anyways. Replace the bias jumper circuit wire. If you have a warning module, actually called a lubalert, and your engine is either overheating or you oil level low it will go into protective mode and you will not be able to go above 2000RPM's. This also a possibility. It is also a possibility that your engine is neither overheating nor low on oil and that either the warning module is faulty, the overheat switch is grounding out with the block somewhere or the oil sensor is bad.<br /><br />-The surging aspect sounds like a fuel problem. Start at the fuel tank (anti-syphon valve and tank vent) and work your way to the fuel pump and then to the carbs. If by pumping the primer bulb saves the engine from surging or bogging your fuel pump needs a rebuild. If not move onto the carbs. A gasket kit for each carb is around 6 bucks. Clean em', blow out with compressed air, and reassemble with new gaskets. How is the condition of the fuel line(s), if they are hard replace with new lines and primer bulbs. If you find varnish in the carbs, I would replace all fuel lines, primer bulbs and rebuild fuel pumps.<br /><br />-As for the oil injection I personally would disconnect and opt for a premix. They are not as dependable as say VRO's or OMS pumps. My 2 cents.<br /><br />-With these older mercs (and newer ones for that matter) the name of the game is preventative mainenance. Your two main concerns are fuel and cooling related. Change the waterpump, tstats, and poppet assembly every other year and clean your carbs and rebuild the fuel pump every three years or so, you could also change out the head gasket then as well.<br /><br />Everyone has there own opinions and these are just mine. Just remember you treat your engines good and the will get you home safe.<br /><br />Good luck and keep posting.

 

[gss036]

Re: mariner 150

What Andy is saying, plus+,, sounds like you are saying both engines are running bad?? 1st thing is to check your water seperator filter to make sure it is not full of water, this will cause surge and fuel starvation. You burn the fuel off the top of the water faster than it can be replaced. A new filter would be the best solutition, after checking the old one for water.

 

[gss036]

Re: mariner 150

What Andy is saying, plus+,, sounds like you are saying both engines are running bad?? 1st thing is to check your water seperator filter to make sure it is not full of water, this will cause surge and fuel starvation. You burn the fuel off the top of the water faster than it can be replaced. A new filter would be the best solutition, after checking the old one for water.<br />If you want to repair the plastic drive gear, you have to slpit the bolock, very spend thing to do. If you decide to run pre mix, there are kits out there to remove the oil injection systems. Do a search above.

 

[Texasmark]

Re: mariner 150

And don't forget to check the quality of your fuel. Some built in tanks with seldom use have some really crappy stuff for gasoline.<br /><br />I think I'd clean the whole fuel system out; tank, lines, filters (in the tank, and any on the boat and on the engine), water separator, and hoses and start from there. <br /><br />When finished, take something like a popsickle stick and push the fuel connector open (at the engine inlet) and squeeze the bulb forcing fuel out of the line to insure it is there, is clean, and fresh.<br /><br />This is easy and cheap and could be the problem. Besides you should do it anyway to have a fresh start. Then go on to other things.<br /><br />If there is no water separating filter, previous owner may have used an alcohol based water absorber which will gell up with the water and that gell can and will clog your fuel system and could cause your symptoms. BTDT <br /><br />Course the overheated wire could signal something, but maybe it is leftover from an old malfunction that has already been fixed by the previous owner.<br /><br />350 hours on a boat that size? Says you go out in the bay...long rides. So 2 hrs out and 2 hrs back per trip is only 80(ish) fishing trips. Shoot those engines are just puppies. Grin.<br /><br />HTH,<br /><br />Mark

 

[andy6374]

Re: mariner 150

Good point Mark.<br /><br />Sour fuel will always give ya the can of worms.