2003 90 hp outboard stalling carb?

rsgonza

Seaman
Joined
Feb 18, 2002
Messages
72
I have a 2003 90 hp 2 stroke merc outboard my problem stated last week while fishing .I notice boat took longer to start than normal.as I took off about 3000rpm it flat out died.I restarted it using choke and had throttle up half way as it started to throttle up I hit choke a couple of times and it started I took off again about 3to 5 min and it died sqeezed primer bulb and it seems firm.I then notice a tapping noise mabye lean condition? brought boat back to dock and brought it home.checkd plugs they are fairly new.all look the same has good compression my concern is the tapping noise.and well should I remove and clean carbs?they have never been off.should I look at fuel pump and also the oil injection system seemed to be working although i did not notice much smoke ,well when i choke it it did spit out tons of smoke.should plugs look dry?they are I though they wld be a little oily.whats with the slight tap.hope its not a rod knock.how hard is it too remove and clean the carbs?and does it have a fuel filter i should replace its never been replaced also does oil tank have any kind of filter .sorry so many questions.I'm an auot tech I think I can handle cleaning carbs.thank you.
 

stremo

Recruit
Joined
Oct 16, 2008
Messages
5
Re: 2003 90 hp outboard stalling carb?

Hi mate I have the same problems but it doesnt stall just a very bad pinging when i go to open it up and then it dies i cleaned the carbys and drained all the old fuel out replaced filters most fuel lines took it out today did the same thing there was speed boat next to he asked what was wrong i told him and he said that my coil pack sounds stuffed or its jumping and at high speed it cant handle it so when i got in took cover off and i could here zapping sound so there is something jumping around the coil so i will go to the electrics tomoro that maybe your problem but it sounds just like yours and jess its a horrible sound was goner pull it right apart .
cheers Tim
 

rsgonza

Seaman
Joined
Feb 18, 2002
Messages
72
Re: 2003 90 hp outboard stalling carb?

Thanks Mate,
Ya boy that sound is whats scares me. but I also will keep you intouch as to what i do.I have a neigbor who ownes a boat reapair /guide service.I went out fishing with him yesterday since he had no trips [I should have had him look at my boat]But we chose the fishing of course.I regret it now.he is booked till next week,anyway he may come over and check it sunday.I'll let you know what we find or what he thinks,and you do the same and mabye we can get back in the water.I did want to clean carbs and change the fuel filter its an 2003 and nothing has ever been done.is it hard to remove the carbs,does it have only that small fuel filter.and also im told i dont need carb kits to clean[gaskets} and last Thank you for the reply.Take care.
 

stremo

Recruit
Joined
Oct 16, 2008
Messages
5
Re: 2003 90 hp outboard stalling carb?

Hi rs I just removed each carby they are really easy to get off pull them down soaked them in petrol for a little while then got the compressor air to blow them out today i changed spark plug leads my old ones where really soft the ends broke on all them plus i had water around my coil pack cleaned them out goner try it again today plus there were no cracks at all still in top condition if this doesnt work will be pulling power head of and looking at bigend bearings the noise i hear just doesnt sound like anything but internal sounds like i got a bolt loose in there above 3000rpm idles fine get on the plane fine then nock nock pingping then loose all power got great compression to it only has that one filter plus all my gaskets are in great condition just be carefull pulling them down dont rip any off them i had to get a sharp blade and just seperate them let me know how you go
cheers Tim
Opps i forgot i did notice them my plugs where really wet with 2 stroke so im thinking that its not geting burned
 

rsgonza

Seaman
Joined
Feb 18, 2002
Messages
72
Re: 2003 90 hp outboard stalling carb?

well today I pulled the air box cover [1st time] and could not pul it up.Come to find out the bottom carb bolt had come out completly.jeeze,it looked as though it is sealed though?i started bolt back into the theads and got the cover off,the top two carbs have studs and the very bottom have bolts.I looked and looked at the carb gasket and it seems like its sealed even with the carb bolt loose.but ill find out tomarrow I ordered plugs and fuel filter and will go ahead and clean the carbs,if there just though two bolts they look easy.then i will pray.hopefully the bolt loose is the problem vacuum leak but I really dnt think I can be that lucky.LOL,Ill let you no good luck.
 

rsgonza

Seaman
Joined
Feb 18, 2002
Messages
72
Re: 2003 90 hp outboard stalling carb?

ok well I have it running,cleaned carbs not very dirty replaced fuel filter ,drained oil from tank and cleaned tank.I put fresh oil in and also gas now engine starts and revs up good.out of the water.I hear a knocking noise.I'm an auto tech and I dont know if the rod bearings are like the gas engine or other type,like cycles needle bearings.I may be freakingout,mabye i should take it to the lake .but I have a prob I dont see any smoke at idle or very little.This really worries me with a knock noise.last week when the engine acted up it sounded like a tapping noise now it sounds like a rod knock,
I am wondering if the oil injection is even working can someone tell me how i can check this .or test it .shld i put oil in gas tank and drive it to the lake and ride around low idle while i mark oil tank.Im sure it will smoke like crazy but is there any way to test the injection system.I know the tank never ran dry and I think it used about a quart the week it started to bog down but should i even run it with the knock now I have check comp .thumb.they seem good .I boat/guide frnd told me he wld suspect if the oil injection was out it wld score cyl's first before damaging rods.but i cant isolate noise.I pulled the plug wires while idleing and noise stayed the same.I then proceded to do this check i found on this site to check for bearing damage,pull plugs stick an extenion or screwdriver turn flywheel by hand to tdc. pull down an inch and then push on extension to see if rods wrist pins have play .everything seemed tight.but I hear a noise.what do you all rec.shld i take it to lake boat ramp tomarrow since it will be slow and drop it in water and listen?shld i even have it on.is there a way to check that 2003 merc 90 hp oil injection.what does it consist of.I was thinking adding oil in gas and running it at low idle .the last thing I want is to blow a hole in block.man I'm worried .dam thing just went out of warranty 5 yrs.>man just paid for boat 2 months ago 19ft kenner.any help wld be apreciated.I'm off tomarrow so I'll consider all replies thanks to all.
 

mikeneal

Senior Chief Petty Officer
Joined
Jan 28, 2004
Messages
710
Re: 2003 90 hp outboard stalling carb?

If you suspect the oil injection is not working properly I would mix up a stand alone tank of 50:1 and remove the output hose on the pump to see if if it is pumping. the manual has a volume spec for the pump output but cant recall what it was, can look it up for you if you want. (I own a '99 90 HP Merc. )

You gotta be WAY careful of the spinning prop but does the noise change if in gear? Wondering if the noise is in the lower unit.

ok well I have it running,cleaned carbs not very dirty replaced fuel filter ,drained oil from tank and cleaned tank.I put fresh oil in and also gas now engine starts and revs up good.out of the water.I hear a knocking noise.I'm an auto tech and I dont know if the rod bearings are like the gas engine or other type,like cycles needle bearings.I may be freakingout,mabye i should take it to the lake .but I have a prob I dont see any smoke at idle or very little.This really worries me with a knock noise.last week when the engine acted up it sounded like a tapping noise now it sounds like a rod knock,
I am wondering if the oil injection is even working can someone tell me how i can check this .or test it .shld i put oil in gas tank and drive it to the lake and ride around low idle while i mark oil tank.Im sure it will smoke like crazy but is there any way to test the injection system.I know the tank never ran dry and I think it used about a quart the week it started to bog down but should i even run it with the knock now I have check comp .thumb.they seem good .I boat/guide frnd told me he wld suspect if the oil injection was out it wld score cyl's first before damaging rods.but i cant isolate noise.I pulled the plug wires while idleing and noise stayed the same.I then proceded to do this check i found on this site to check for bearing damage,pull plugs stick an extenion or screwdriver turn flywheel by hand to tdc. pull down an inch and then push on extension to see if rods wrist pins have play .everything seemed tight.but I hear a noise.what do you all rec.shld i take it to lake boat ramp tomarrow since it will be slow and drop it in water and listen?shld i even have it on.is there a way to check that 2003 merc 90 hp oil injection.what does it consist of.I was thinking adding oil in gas and running it at low idle .the last thing I want is to blow a hole in block.man I'm worried .dam thing just went out of warranty 5 yrs.>man just paid for boat 2 months ago 19ft kenner.any help wld be apreciated.I'm off tomarrow so I'll consider all replies thanks to all.
 

rsgonza

Seaman
Joined
Feb 18, 2002
Messages
72
Re: 2003 90 hp outboard stalling carb?

no sir noise does not change,and want bother me is there is no smoke at all.I boat tech mentioned to me he found it odd that it could be a rod knock in his opinion with no oil he thinks the cyls would be affected and compression would be affected so you may have a point,then again its now running and idleing but out of the water I'm not very exp at outboards so i am gona mix up my gas like you said and drive it to the lake and dock it mabye run around real low rpms.and check the oil level in take after an hour.I'll let you know.is the pump drive plastic .I have read about oil injection but from a 89 manuel mine is 2003 has it changed much.I can tell you this it never ran dry,but there was a low pitch very low pitch beeping sound before all this.now I did run it low to the point the tank sensor went off and that was super loud comming from the engine this noise was from under the console are they the same alarm.
 

rsgonza

Seaman
Joined
Feb 18, 2002
Messages
72
Re: 2003 90 hp outboard stalling carb? new problem?

Re: 2003 90 hp outboard stalling carb? new problem?

well ok I went ahead and marked the oil tank and premixed fuel.then I took it out tuesday yesterday,the engine ran great,I also did a compression test 125psi all three cyl.now for some reason if I pull the plug wire while its running the middle cyl does not drop rpms like the top and bottom there is a change but mabye thats normal.anyway it appears the oil is being injected after i ran it two hours.[I know big chance I took} the noise did not get louder,it almost seemed like it got quiet at higher rpm's but then again the engine is loud.The stalling problem is gone I did take it up to 2500 rpm on plane once and it ran like it always has but it has a knock.and it does not change with me changing gears.The boat tech came by and well it stumped him.he checked rods for play none he check comp none he said he checked reed valves?ok either he not much of a boat tech,well he is my neighbor and has has a shop for 10 yrs so he should know something.I was thinking piston skirt slap?main bearings?I dont know I guess ill tear it down this winter.get this I bought the extended plan 5 years and the 5 yrs were up in march.aint that a B_tch.man I'm lost.no more stalling or dying and now my boats a mosqito killer.premix gas oil injection seems to be working anyone out there the engine is a 90 hp elpto thanks to all
 

rsgonza

Seaman
Joined
Feb 18, 2002
Messages
72
Im tearing down

Im tearing down

comp is good the noise sure seems like a piston slap.silly question?can I have good comp and have piston slap? and can I remove the cyl cover to check pistons or do i have to remove powerhead<also can someone rec a good place to get good quality patys cheap. please.
 

charliewheelton

Recruit
Joined
Jun 4, 2009
Messages
1
Re: 2003 90 hp outboard stalling carb?

did you find out what the noise was yet?
I just bought a 75 hp merc 2002. Runs great but has a bad knock and im paranoid of blowing it up.
i noticed at night that my plug wires are arcing and am going to change them
 
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