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200 hp getting gas in oil

rogdemr

New member
I have honda 200 hp motor that is getting gas in oil i have changed oil but it still is getting in it is fuel injected mide 2000s any answers out there? and what lower units hp will interchange with it.
 
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I've seen many cases not just with Honda but also with Yamaha. Thermostats may need to be replaced. Air temp sensor could be faulty. Causing engine to run on "enriched mixture" There is a possibility that it could be leaking from the back of the lift pump on the valve cover. There is also the possibility of worn or bad rings, let's hope not. Manufactures have concluded that this issue does occur. I have one commerical oilfield customer that suffered with this problem on his Honda. Come to find out he was only traveling across a small bayou to check a well. Every morning he would get in his boat as he has for ten years before, start it and jam it in gear. Never allowing the unit to come up to operating temp. Thus the engine was always running on an enriched mixture for cold start. Make sure your fuel is of good quality, also make sure that you have NGK spark plugs in your unit and not Nippon Denso. Run a mixture of Sea Foam and Yamaha ring free thru your unit and see if the issue doesn't go away. I have seen too many units that the oil control rings were seized in the piston groove. If all fails, have your tech perform a leak down test and then the truth be known. Thanks Martin
 
That's all very good advice from Martin. Let me add a bit more detail. My usual protocol is start with the simple, then move on by level of difficulty. On this particular engine, the t-stats are the usual culprit, so that is the first place I would look.

If you have a temp gun or other way of measuring engine temp, warm up the engine and test the head temp. This engine does not reach full operating temp at idle, so you need to run it around a bit before taking your readings. Operating temp is around 160 - 170 F. If you are getting a full 160 F on BOTH heads, then look elsewhere for the problem. While doing this, test the temp of the water coming out of the indicator. It should be about the same temperature as you would feel in a hot tub.

If running cold, pull the t-stats and first check that neither is stuck open. If so, replace both. If not stuck open, heat them in a pot of water. They should begin to open at 140 F and be completely open at 160 F. Completely open means at least 3 MM. If either fails the test, replacee both.

If operating temp is not your problem, then as Martin said, decarbonize the engine using either Sea Foam (cheaper) or YamaLube Ring Free (more expensive, put better.) Caution, make sure you decarbonize in a place where all the dirty crap that comes out of the exhaust can be dissipated. I still have black splotches on my garage door from decarbonizing an old Johnson SeaPro.
 
thanks for the advise i will try t stats first.
what about lower units are there diffrent size motors that will inter change as i need one of thease to.
 
I think you are stuck with a BF 200 or BF 225 lower unit. Why does yours need to be replaced? There are several companies that offer rebuilt lower units. Look on the web.
 
hey chawk_man--

when you recommend Yamalube ring-free as an (expensive) alternative to Seafoam, how would you do the application? Are we talking just normal mix into the gas tank per instructions on the bottle or some type of shock-treatment, and if the latter, would this be by separate tank with minimal dilution ?
thanks
 
We're talking about the concentrated mix shock treatment using a seperate tank - usually a six gallon tank for a big motor. Instructions for decarbonizing are on the container. Sea Foam container also has instructions on the can. The key to decarbonizing this way is to let the engine sit awhile once it has been loaded up with the decarbonizer. Repeat until you get no black smoke. Many folks swear by Sea Foam, and it is a good product, but I'm on the cautious side and use the Ring Free because it claims to be specifically formulated for outboards. I think either will do an adequate job, and Sea Foam is readily available.

Once decarbonized, then keep your fuel treated by either filling up with Valvtec treated gas or adding Sea Foam or Ring Free (or similar) at each fill up. This is especially important if you do a lot of trolling or low speed cruising. In my area, several marinas sell Valvtec treated gasoline, which costs about 10 cents a gallon more than untreated. However, that premium is generally less expensive than adding your own decarb formula at each fill up. Besides, you don't have to worry about remembering to do it (which is important at my age) or measuring out the right amount at each fill up.
 
O.K, thanks for that chawk_man--- out here on the west coast where occasionally I'm in remote locations (Vancouver Island) , you put in your boat what's available and a lot of times it's 10% ethanol treated---I always used ring-free and Marine Stabil at every fill to counter-act that additive. Never tried the shock-treatment but maybe it's time. Thanks again
 
Marketic - There are two different issues at play here. You need to use a fuel stabilizer to prevent E-10 gas from aging rapidly going through a phase seperation. Marine Stabil is probably the best for that. Startron is a less expensive alternative. In addition, you should also use a decarbonizing agent (Sea Foam or Ring Free or simular) to prevent carbon build up in you injectors, valves, and rings. Valvtec claims to do both.
 
One other thing I forgot to mention. Once you decarbonize your engine, change the oil because of possible contamination from the decarbonizer agent. Also, consider pulling your plugs and cleaning them if there is a lot of black soot on the electrodes.
 
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