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excessive smoking at start 1998 225hp evinrude OP

mmthunt

New member
I have two 1998 225hp evinrude ocean pros which smoke excessively (imo) at start, clears up at acceleration and increases again at idle. Engines run well at idle and at power. VRO pumps or something else? Could ethanol have damaged the seals or gaskets on the VRO permitting air to leak in and decreasing thr fuel to oil mixture at idle? The engine which smokes most burns more oil than the other. Should I replace VROs or convert to pre-mix? Non-ethanol is now available here and I am now using that fuel. Can't afford to re-power just yet.:confused:
 
Ethanol is not the big boogey man many are making it out to be - it's a convenient excuse to cover everything from normal wear/tear to downright neglect of an outboard. If ethanol was as bad as some would have you believe practically every car/truck on the road would spend most of it's life in the repair bay. I have ran E-15 (15% ethanol which is now approved for sale in the US) in all four of my outboards for the last two seasons (they had run E-10 for at least 10 years before that) and have zero issues related to the fuel - and my motors are 1986, 1986, 1987 and 1991 models - so not brand new by any means.

Now as to your issue. Some smoke on start-up may simply be due to the length of time between start-up's. When a motor sits the fuel trapped in the system will evaporate leaving the oil behind which burns up on the next start, creating "excess" smoke. So a bit of a smokey start could be "normal".

If you have one engine burning more oil than the other and it appears to smoke at idle then you may infact have a real issue. It could be a partially clogged fuel line or filter feeding that one engine which is allowing for a slightly rich oil mix, however, there should be fuel restriction alarm on your particular model that monitors the vaccum pressure on the fuel line entering the VRO which would alarm if there is a restriction (assuming it's working), however, at idle/near idle, when the vaccum is low to begin with, it may not detect a problem - it should however, alarm at higher rpms if a restriction is significant.

If you can rule out a fuel restriction then your VRO itself may be on the way out.

The flow rate of oil can be tested (repair manual has the proceedure). If it is in fact "sucking too much oil", the first thing to replace is the pulse limiter (the little fitting on the crankcase that supplies the pressure to run the pump). If it's ok, then a rebuild or replacement of the VRO is required.

OR, you simply put up with a bit of extra smoke.

What do the sparkplugs look like on the "oil rich" engine - overly oil fouled??
 
Come down to southwest FL sometime and see what the lovely E-10 fuel does to mtrs down here. All the marinas down here now have non-ethonal fuel because of all the probs it's caused. And I'll bet you don't have too many boats with water seperator filters on them up where you live.
 
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Actually we do. Condensation and phase separation problems are far more common in the north where we have wild temperature swings and most motors are layed up (stored) for 6 months or more each year when the lakes turn solid.

In the little over 30 years I have been working on outboards, mostly Merc's, one has never come to me because it was "properly" maintained by the owner.

Ask anyone that works on them on a regular basis, whether or not the motors are running ethanol enhanced fuel, and you just don't hear stories like this -

I run new/fresh stablized fuel anytime my boat has been sitting for more than a couple of days;

I change my sparkplugs once a year or every 100 hours as recommended by the mfg;

Likewise, all adjustments, oil changes, lower unit service etc is done according to my owners manual;

Anytime the motor will be idle for more than 2 weeks I "winterize" it;

Everytime it sees any salt water, dirty, gritty or polluted water, the motor gets flushed;

I follow the owners manual in every respect, including the lubrication schedule for all moving parts;

And despite all of the above my motor has all these issues - It just doesn't happen. Any fuel related issue is almost certainly a fault of the owner/operator in 99.99% of the cases.

If forums had of existed back when we went from leaded to unleaded fuel, you would have read similar horror stories and tales of impending doom which never came to pass.

Maybe they simply made better outboards back in the 70's - after all there are still many running fine today on E-10 fuel....
 
There have been a few posts whereas a vent problem existed with the oil tank, resulting in a build up of pressure within the tank. Unlikely in cold areas, more likely in warm areas. However, having a identical vent problem in both oil tanks is not likely.

Another cause of excessive oil usage would be a slight fuel restriction (fuel line IDs too small, anti siphon valve sticking, etc). I assume that at one time the engines ran normally, and if so, that eliminates any improper fuel line ID problem but the anti siphon valve(s) might be suspect.

(Fuel Anti Siphon Valve)
(J. Reeves)

Many of the later OMC V/6 engines incorporate a fuel restriction warning via a vacuum device attached to the powerhead. If the engine overheats, or if you have a fuel restriction, the warning is the same.... a steady constant beep.

NOTE... Only the V/6 & V/8 engines have the above "Fuel Restriction Warning". The warning horn will not sound on the other models.

The fact that a engine is not overheating, but the warning horn sounds off with a constant steady beep, and that the rpms drop drastically would indicate that the engine is starving for fuel due to a fuel restriction. Check the built in fuel tank where the rubber fuel line attaches to the tank fitting. That fitting is in all probability a "Anti Siphon" valve which is notorious for sticking in a semi closed position. It will be aluminum, about 2" long, and the insides of it will consist of a spring, a ball, and a ball seat. If this valve exists, remove it, knock out those inner components which will convert it to a straight through fitting, then re-install it. Hopefully that cures the problem.

The above procedure will cure a restriction problem with the anti siphon valve as stated. BUT, it may also allow fuel to drain backwards to the fuel tank when the engine is not running (siphoning backwards) due to the fact that the carburetors/fuel pump etc are higher than the fuel tank. This condition is not an absolute as the valves in the fuel primer bulb usually prevent this backwards siphoning problem. However.... if this does take place, the cure would be to install a new anti siphon valve.
 
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Thanks to all that replied. I recognize some areas which I need to check such as leakage in the fuel system. I can see minute bubbles on a seal of the VRO on the engine using the most oil. Additionally there are screw clamps on some of the fuel fittings. I will certainly change the anti-siphon valves. Plugs are changed once a year, there are water seperaters and the filters are changed every six months. It would seem that a close inspection of the entire fuel system is in order and replacement of the offending VRO. As to ethanol, prior to the availability of non-ethanol in the Keys, we treated the fuel with the correct additive and four years ago the VRO pumps were replaced but as I said there is an air leak in one of the pumps. Many thanks to the forum members. This a valuable resource for the boating public.
 
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