Merc 225 1996 Efi. Excessive Smoke

[ranger188vs]

I Have A 1996 Merc. 225 Efi , I Get Heavy Oil On Lower 2 Plugs And Light Oil On Upper 4 Plugs... When I Put In New Plugs Runs Great For 1 Day Next Day I Get Excessive Smoke And Starts Running Like An Old Pinto Check Plugs Again And Same Oil Problem

 

[gcboat]

Re: Merc 225 1996 Efi. Excessive Smoke

1st thing I'd do would be to pull a compression check on her. At least you'll have some number's to start with. Also check and see if you are running the correct heat range for your plugs. Other than that you'll have to wait for a real mechanic to chime in.

 

[dsinger]

Re: Merc 225 1996 Efi. Excessive Smoke

When was the last decarb especially if you troll alot.

 

[ranger188vs]

Re: Merc 225 1996 Efi. Excessive Smoke

i don't troll with the main motor ...this is an excessive oiling problem need suggestions on what might be causing excessive oil

 

[ranger188vs]

Re: Merc 225 1996 Efi. Excessive Smoke

First off thanks for your reply. Compression is good ranges 105 to 110 on all 6cylinders..Have proper spark plugs champion QL77CC... This motor is on a bass boat so i dont troll. I Have had the boat for 3 years and never had it decarbed. What and how do i decarb? Will this stop the excessive oil on plugs? With new plugs she runs like a raped ape!! , then plugs are fouled with oil within 20-25 miles. THANKS AGAIN!!!!

 

[grego]

Re: Merc 225 1996 Efi. Excessive Smoke

Oil induction pump needs to be calibrated. Oh!.yeah,make sure you close oil tank lid firmly,open air is not good!

 

[ranger188vs]

Re: Merc 225 1996 Efi. Excessive Smoke

Thanks Grego,I have had the motor checked by a tech for this excessive smoke/oil and they said it was within the specs. Im sure they could wrong. But thats what they said. How do you calibrate the induction pump? THANKS AGAIN!!!!

 

[Faztbullet]

Re: Merc 225 1996 Efi. Excessive Smoke

Hello.. Couple of questions for ya.. Is engine harder to start and smokes bad that clears as you use it?

 

[CharlieB]

Re: Merc 225 1996 Efi. Excessive Smoke

Check all the little recirc hoses and fittings/valves.

The recirc system SHOULD redistribute any excess oil evenly throughout all cyl's.

Clogged lines and/or fittings will allow the oil to pool and cause spark plug fouling.

Check your piston to spark plug clearance and try running NGK BPR7HS plugs gapped at .032, they will withstand oiling far better than the surface gap plugs. You will like the price of these a whole lot better also!

 

[ranger188vs]

Re: Merc 225 1996 Efi. Excessive Smoke

Fazt Bullet The motor has always started easy, but lots of smoke. She would also clear out. I rencently replace my gears in the lower unit. Since then she sounds different, ildes rough and smokes alot worse, and is harder to start now. Last trip out i had to clear the motor in nuetral at launch time, which i never had to do in the past. The motor smoked alot during that day on start ups. THANKS AGAIN!!!!

 

[ranger188vs]

Re: Merc 225 1996 Efi. Excessive Smoke

Charlie B Just so Happens i looked at that last night. I notice moisture of oil on the lower 2. If i know what your talking about they have the square tapped fitting with small black hoses. Ill look at it closer. How do i check piston to plug clearance? THANKS AGAIN!!!!

 

[ranger188vs]

Re: Merc 225 1996 Efi. Excessive Smoke

Charlie B Ok i looked at the recirc lines a litte closer, and found that they dry,cracked.I imagine that this would allow air in these lines and trick the motor and send more oil into the system. Causing my promblem .( very possible? ) Bought new hose. Find out mid Jan. Ill let you know how things go. THANKS AGAIN !!!!

 

[j_martin]

Re: Merc 225 1996 Efi. Excessive Smoke

Charlie B Ok i looked at the recirc lines a litte closer, and found that they dry,cracked.I imagine that this would allow air in these lines and trick the motor and send more oil into the system. Causing my promblem .( very possible? ) Bought new hose. Find out mid Jan. Ill let you know how things go. THANKS AGAIN !!!!

The motor don't have any brains attached to the oil injection. Just engine drive and throttle position, both mechanical.

Bad bleed lines will cause it to load up and misfire at idle, though, and probably is your main issue.

While you're at it, get a manual, be sure you understand exactly which engine configuration you own, and be sure the bleed hose routing is correct.

If plastic parts are getting old and cranky, could be some of the plastic innards in the check valve that supplies pressure to the boat oil tank are getting iffy. Should be enough pressure on the tank to hear it when you crack the cap just after running the engine, but not enough to distort the tank shape. 5 minutes after shutdown, the pressure should be gone.

hope it helps
John

 

[ranger188vs]

Re: Merc 225 1996 Efi. Excessive Smoke

J Martin Yes all info is very helpfull. Manual is on its way. Bleed lines and recirc lines are the same? Ill change 1 line at a time... THANKS AGAIN!!!!

 

[rodbolt]

Re: Merc 225 1996 Efi. Excessive Smoke

not all EFI mercs used the recirc and bleed lines.
I dont post here much but the EFI merc in that year range is very similar to the OX66 yamaha.
I would start by checking spark and compression, then check the low pressure fuel pump or simply rebuild it if it hasnt been done recently.
the oiling system mixes the oil in the VST so all 6 cylinders are injected the same mix, other than possibly having a bad oil pump shaft sel I would not hunt on the pump itself that hard.
if the oil tank pressure fitting on the stbd lower front of the block is failing it can cause a very rich oil mix in the VST but it should clear up in a few minutes of running.
the surface gap plugs are reccomended for most high RPM sustained running like most bass boats see.
if compression is good,and I suspect it will be, if spark can jump a 7/16th gap on all 6 then I would carefully inspect the lift pump,fuel pump screen and VST filter.normally if the pump shaft seals leak the center two cylinders are heavy on oil.
the last issue we see occasionally is low stator charge coil voltage after a period of run time.
but remember,all 6 cylinders feed from the same fuel/oil mix from the VST two cannot get more or less oil than the other 4 unless its coming from a place other than the oil pump outlet.
a picture of your VST tank will help a lot as I havent worked for a mercury dealer in about 10 years but I still see a few at the drystack and some ctually used the same VST as certain OX66 yamahas.
if your engine uses bleed and recirc lines then you will need a syringe and some isopropyl alcohol to test the recirc check valves.

 

[ranger188vs]

Re: Merc 225 1996 Efi. Excessive Smoke

THANKS RODBOLT Im going to the lake next weekend.. What i have done is replaced the bleed lines / recirc lines and ill go run her. Lines looked bad. I want to try one thing at a time so i know what fixes her.. I will get back next week. THANKS AGAIN !!!

 

[ranger188vs]

Re: Merc 225 1996 Efi. Excessive Smoke

Alright I replaced the bleed lines & checked all in line check valves. All open & close. Motor now idles at 1200 rpm's from 800 rpm's with old bleed lines... Motor has identified the change, this is a good thing right? I would like to know the reason for it. THANKS AGAIN!!!!