Engine making oil fix

It sounds like you are getting somewhere. Bad computers do really strange things. A friend had a car that would die randomly and the shop couldn't figure out what was wrong with it. He spent a fortune in towing and "repairs" trying to fix it. I bought the car from him as he was so sick of it and needed something dependable. A new ECM fixed it and my niece drove it for years without issue.
 
My 2005 C-Dory came with a 2017 Suzuki 115hp. Ran good at first. Then had the water in fuel alarm go off. Almost gave me a heart attack. I then started smelling gas. Ran it a couple more times after changing the fuel water separator and smelled heavy gas fumes. The engine had 37 hours. Started it while on the hook and it looked like the Exxon Valdez coming out the foot. Big rainbow and not the good kind. I took it to Sportscraft for repair. Turns out it was a stuck needle valve and float. $550.00 later it runs like a champ.

Hope your engine only needs a computer instead of replacement. DR.
Bob is a real pro at diagnosis of hard to figure out mechanical issues 👍
 
Well it's not the computer. Brand new computer with 0 hrs. on it.
Bad news is I met a Yamaha shop foreman and told him my story on making oil. He said the computer wouldn't fix it( right about that) but says he knows what will. If you met this guy you would understand why I don't like him, at all.
I'm going to talk with my guy about this and if he has anything else we can try. If not I am going to try this other guy, after he and I establish some ground rules. He's probably trust worthy but still a major ah.
The story continues.
Benton
 
With my last oil change I noticed a red tint to the used oil. The last fuel I had ran was red died Canadian marine regular. Obviously my 200 hr fuel injected Honda BF90 was ingesting unburned fuel into the crankcase. My last use of the motor was on Yellowstone Lake at 7’700’. I was improperly running a 15.5 pitch prop for that elevation/ density altitude, resulting in low RPM. That combined with a probable stuck open thermostat resulted in the motor running too cool.

I had the Honda tech scan the computer. It showed no codes but did capture the last 4 hrs of operation on Yellowstone Lake at low rpm and under operating temperature. The fix is new block and head thermostats and using am 9 pitch prop at that elevation. Fortunately no damage. Probably not your issue but another reason the motor can make oil. Ken
 
Well I just want to give an update on my Yamaha oil making saga.
My tech has been a bit slow so Finale has been sitting on the trailer.
The new computer didn't have any impact on the issue.
We are going to check the fuel pressure regulator next week.
My tech says if that isn't the problem then he is out of ideas. He doesn't think a prop change would fix it since the engine runs great, 5,400 rpm and 40 mph on a calm day. Compression 220 and leak down test was perfect.
If any of you have the CD 25' with Yamaha 200 4 cyl please send me the prop size just so I can tell him that.
If necessary I am going to another certified Yamaha tech who was referred to me.
Benton :smilep
 
BBlalock":2qnpz58d said:
My 2013 Yamaha 200 has made oil for a while. Every 6-7 hrs I was changing the oil. Oil level rose about 1/2" in that time. Seemed to run just fine. 610 hrs.
Had the bleed down test yesterday and was told they could not get any of the cylinders past 90#. Told should be around 200#. We discussed how did it even run with that low of pressure.
The fix appears to be $26k for a new 200. It can be installed by the end of next week.
Does it make good sense to go this route when I'm thinking I would have a boat for 1-2 more years? My son's have boats and they say use theirs.
Or, sell as is and allow for the new owner to repower as they want.
:sad
Benton
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Engine needs to make 6000 RPM at WOT.
I would go down a inch or two in pitch.
Does the oil smell like GAS?
Impossible to "make oil" either water(you ruled out) or GAS!
If not FP reg. then stuck float/needle in H/P fuel pump tank.
 
tsturm":3v28h4eb said:
Engine needs to make 6000 RPM at WOT.
I would go down a inch or two in pitch.
Does the oil smell like GAS?
Impossible to "make oil" either water(you ruled out) or GAS!
If not FP reg. then stuck float/needle in H/P fuel pump tank.
Click to expand...

Also a leaking diaphragm, in L/P fuel pump dumps fuel/gas into the crankcase.
 
tsturm":1jpua5mu said:
tsturm":1jpua5mu said:
Engine needs to make 6000 RPM at WOT.
I would go down a inch or two in pitch.
Does the oil smell like GAS?
Impossible to "make oil" either water(you ruled out) or GAS!
If not FP reg. then stuck float/needle in H/P fuel pump tank.
Click to expand...

Also a leaking diaphragm, in L/P fuel pump dumps fuel/gas into the crankcase.
Click to expand...

Agreed. I am starting to reluctantly think this particular engine might have a porosity issue in the casting, or a small crack or bad gasket somewhere that isn't impacting compression.
 
I don't have a solution:
tsturm wrote:
Also a leaking diaphragm, in L/P fuel pump dumps fuel/gas into the crankcase.
Click to expand...

I had suggested that earlier, and BBlalock response was:

Dr. Bob
Both the low and high pressure electric pumps are outside the engine. Also, if the VST float level is incorrectly set and it overflows, that goes up to the canister and then overboard through the lower cowell.
Click to expand...

I always like to see engines turn up to their rated RPM at WOT, but 40 mph is over where I feel comfortable in a C Dory 25. Tom on C Otter should give you optimal prop-I thought it was 15" pitch--not sure of the diameter, cup, rake etc. for that specific engine. It seems to be one of the most popular for repowers of the C Dory 25.

At this point--a tear down, magnaflux the head first, then the block and check every inch of it--going to take a good mechanic who knows outboards, and not one of these "$1,000" for a rebuild on your engine. Unless you feel capable of doing the take down, and inspection yourself. The compression and leak down most recently were "normal"...Although they were both very low earlier? Makes me wonder how each was done--and some error in the process. Something just does not seem right.

Another thought is to make contact with Yamaha engineers and factory techs, who have dealt with obscure problems. I would try and cultivate some contacts in the "chain of command" for Yamaha. You probably would find openings at major large boat shows where a factory rep may be present. Have all of the information organized and ready to present. Have a recent computer readout on the engine after a full run, to include at least 5 minutes at WOT.
 
The propeller I use on the C-Otter is a stainless steel Yamaha Reliant 14.5 inch by 15 pitch. It has the STS hub that was designed for the 4 cylinder Yamaha 150 to 200 horsepower engines. It’s a good all around choice for a medium to heavy boat. I have 2 other props for spares in case I do something stupid. I run at sea level to about 1200 feet above. No high altitude experience. We have about 1200 engine hours. Currently cruising the Tennessee River.
 
Thanks for these replies, and sorry for the delay getting back into the site.
1. For clarification, "making oil" is a mechanics term for gas getting into the crankcase and increasing the amount of 'oil' in the engine. Water in the oil is easy to see.
2. The low initial compression and leak down #'s I think was for the purpose of selling a new motor. I watched the second guy do the tests to get good #'s.
3. This motor doesn't have an internal fuel pump and there isn't a diaphragm on it. There is a low pressure pump for getting gas out of the tank to the VST and a high pressure pump in the VST for the fuel injection.
4. If the VST overflows that goes up into the canister which overflows through a tube into the lower engine cowl and into the water.
5. The 'Yamaha' mechanics tech book says 5-6k rpm is normal. I'm at 5,400 rpm. And, yes, 40 mph is not a secure feeling ride with this boat. It slides a bit.
6. As it is now we are 'supposed' to check the fuel pressure regulator this week.
7. If it tests good then I'm going to see about the prop suggestions I received, since that is relatively cheap.
8. Lastly I'll consider the tear down. And I will use a reputable shop to do the work. 610 hrs on it now.
Benton
:sad
 
Avidmagnum12 and others:
I just checked my prop and it is a PowerTech 23R16P CL200
This is a bit larger than yours, isn't it? Typically I cruse at 4100 rpm and 26-28 mph. 3.0-3.4 mpg on the Yamaha gage.
Tech is supposed to come today to check Fuel Pressure Regulator
As you can tell by my profile I run 100% at sea level.
Benton
 
What is the wide open throttle RPM and Speed on your boat with this 16" pitch prop? This is not related directly to the making oil, rather to if there is lugging of the engine, which I doubt.

Thanks.
 
A correction on the prop size.
The '23' is actually 'Z' 3. It is a 16 pitch PowerTech doesn't label their props as 14.5x16.
I have sent a request for explanation of what prop I have.
 
Your boat is probably much lighter than the C-Otter. I’ve never seen over 3 mpg at 26 to 28 mph. We live on ours for 5 months straight and travel remote areas where it could be self rescue or no rescue. Lots of stuff! Your prop is not far off if you get over 5000 rpm at WOT. My goal is to turn 5500 or more at WOT. I trust you with will work out your oil problem. Took a while to answer back as some of the anchorages we’ve been at had no cell service.
 
Update: Tech coming tomorrow to check the fuel pressure modulator. I have a used aluminum 14.5x17P prop ($48.) to try. Also getting the cost of a powerhead if needed.
Still trying.
Benton
 
Still waiting to test the fuel pressure regulator.
I did get a turn key quote for a rebuilt powerhead $8,700 with 1 yr warranty. My tech has used them many times and has never had an issue with any of their work.
New motor 3x+.
Ran it 4 hrs and gained 1/8" on the dipstick.
Benton
 
BBlalock":12v8b1t3 said:
$8,700
New motor 3x+.
Click to expand...

I am seeing around $15-16k for F200 25" with manual mechanical controls (Not DEC.) I double checked east coast dealers and saw the same price range.

Rigging with your existing controls should be very straight forward, I would expect $1,500 at absolute most for labor.
 
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