Corrosion in the carbs

H

hardee

New member
Corrosion in the carbs is what the mechanics are telling me is causing my Yami 40 (s) to stall out. Here’s what happens; we start, rather hard getting the fire built, then stall out several times during warm-up over 6-8 minutes. Then on a warm-up run, at about 2800RPM the starboard side dies out again. Restarts readily, and runs for 15 minutes, then dies out again. After several repeats, I was 1. Glad I had twins on the transom, 2. Wondering what was up since this is our first run since being back to the shop for new plugs, start and run, and trim indicator cam replacement and adjusting. Boat was serviced, fluids changed, fuel stabilized, fogged, water system antifreezed, and trailer bearings checked last fall, (Nov) then placed in inside storage, dehumidified and battery checked and charged every couple of weeks until March. Had been run at least once a month since the previous March. Prior to that and our purchasing, there was a lay-up of maybe 5 months, Temps in 45 – 75 bracket. We purchased in November and had it serviced immediately and set up for winter storage, so was not run except at the mechanics for approximately 1 year. I’m quite certain there was stabil in the gas then, and there was a partly used can of Yamaha Ring Free, with the boat supplies. (Sorry, can’t ask the previous owner, he is gone.) the boat had about 200 hours on it and we have put on 80 over the last season, with absolutely no problem.
The mechanics are saying there is corrosion in the carburetor system, flaking off and cause the stallouts. They are offering to rebuild the carbs, to clean out the corrosion for exactly one half of my whole right arm per each engine, (now there is a valid reason to have a single). I would like some feedback on what may be causing this corrosion, and what can be done to see that it does not happen again. Some how I am thinking that the regular service should have picked up on a future problem and something done to prevent it. I am not a mechanic and that is why I take it to a reportedly reputable Yami service place. I hope there is enough info here so that some of you diagnosticians can chime in and offer opinions or alternatives.

It has been suggested to me that Stabil is not a viable product to be using in the marine environment, even when filling with auto gas. Comments please?

Is this a normal service issue by 300 hours? Is it peculiar to Yamaha? Would it be better to run the gas out of the engines each time the boat is loaded onto the trailer? Would more zincs on the OB’s retard the corrosion. Should I be putting some sort of Gas Dryer into the tanks with every fuel fill? Just some more idea’s based on what little I know.

Thank for the help out there. I know there are a lot of you who are experienced and knowledgeable in this area, so thanks in advance

Harvey
SleepyC :moon
 
hardee":1x8hxjzf said:
Corrosion in the carbs is what the mechanics are telling me is causing my Yami 40 (s) to stall out. Here’s what happens; we start, rather hard getting the fire built, then stall out several times during warm-up over 6-8 minutes. Then on a warm-up run, at about 2800RPM the starboard side dies out again. Restarts readily, and runs for 15 minutes, then dies out again. After several repeats, I was 1. Glad I had twins on the transom, 2. Wondering what was up since this is our first run since being back to the shop for new plugs, start and run, and trim indicator cam replacement and adjusting. Boat was serviced, fluids changed, fuel stabilized, fogged, water system antifreezed, and trailer bearings checked last fall, (Nov) then placed in inside storage, dehumidified and battery checked and charged every couple of weeks until March. Had been run at least once a month since the previous March. Prior to that and our purchasing, there was a lay-up of maybe 5 months, Temps in 45 – 75 bracket. We purchased in November and had it serviced immediately and set up for winter storage, so was not run except at the mechanics for approximately 1 year. I’m quite certain there was stabil in the gas then, and there was a partly used can of Yamaha Ring Free, with the boat supplies. (Sorry, can’t ask the previous owner, he is gone.) the boat had about 200 hours on it and we have put on 80 over the last season, with absolutely no problem.
The mechanics are saying there is corrosion in the carburetor system, flaking off and cause the stallouts. They are offering to rebuild the carbs, to clean out the corrosion for exactly one half of my whole right arm per each engine, (now there is a valid reason to have a single). I would like some feedback on what may be causing this corrosion, and what can be done to see that it does not happen again. Some how I am thinking that the regular service should have picked up on a future problem and something done to prevent it. I am not a mechanic and that is why I take it to a reportedly reputable Yami service place. I hope there is enough info here so that some of you diagnosticians can chime in and offer opinions or alternatives.

It has been suggested to me that Stabil is not a viable product to be using in the marine environment, even when filling with auto gas. Comments please?

Is this a normal service issue by 300 hours? Is it peculiar to Yamaha? Would it be better to run the gas out of the engines each time the boat is loaded onto the trailer? Would more zincs on the OB’s retard the corrosion. Should I be putting some sort of Gas Dryer into the tanks with every fuel fill? Just some more idea’s based on what little I know.

Thank for the help out there. I know there are a lot of you who are experienced and knowledgeable in this area, so thanks in advance

Harvey
SleepyC :moon
Click to expand...


Sounds like water in the fuel at present
The Carbs at sometime have had water in them that is what causes the alu,zink alloy to turn to a white/gray powder. Stabil works just fine in my Marine Enviro. (for the last 30yrs.) (you will probably find a rocket surgeon or two who read on the internet this that & other thing wont work etc etc. :wink: ) It sounds like the damage was done or started with the previous owner. I would remove the float bowl drain on each carb, get a can of spray carb cleaner & hose them out real good, replace the drain plugs & test run with Known Clean Fresh Fuel.
 
I had your problem all the time with my Johnson 85 2 stroke. I bought a new Mercury 50 EFI and figured my problems were over. I used fuel stabilizer in it but despite this after it set up for about 3 months it wouldn't start. The high pressure fuel pump wasn't pumping and was locked up. I took it out and tried several types of cleaners before deciding I had to buy a new one at $350. When I went to the Merecury dealer to order a new pump the mechanic suggested I try Quicksilver Power Tune Carb and Engine cleaner. The stuff worked great and freed the pump up immediately saving me $350. I'm usually not sold on these magic cures but after cleaning your bowels and jets I'd give this stuff a try it worked wonders for me. You use it just like any other carb cleaner by spraying in the intake while the engine is at a fast idle.
 
Water in the fuel was the cause. The symtoms you describe (hard starting, frequent stalling) tells you there was water present in the fuel. The subsequent corrosion exasperated the problem. The water was probably introduced during the last fill up, or the last fill up before you winterized. It doesn't take long for the effects to occur.
I would go with the drain the carbs advice, but do it 2 or 3 times to try and get all the sediment out. If you have a filter/water separator system, drain off any water, and try it. If the performance improves, I would run the fuel tanks out, replace the fuel filter, fill up with fresh fuel from a different source, and run with it. Frequent checks of the fuel/water separator (after every outing) until I was sure there was no new water being introduced in the fuel system. Your fuel/water separator is your first line of defence for this occurence, so frequent checking is good preventive maintainance.
If you still have the problem after this, then I would go with the carb rebuild, but only on the affected motor.
I'm not a big fan of fuel or oil additives on a regular basis but I wouldn't be adverse to using a fuel dryer on the remainder of the fuel in the tank and the next tank.
I'm a fan of Stabil in fuel that is not going to be used up right away. I see no distinction in using it in a "marine" envirorment as apposed to the gas in my lawnmower. Once you put fuel in a tank and put the cap on, the outside enviroment has know affect on it. Hope this helps.

Evan (soon to be C-Dory owner)
 
Ok, so what I know so far is the Starboard carbs are out and apart. the corrosion looks more like a deposit, greenish in some areas and White and hard in others, like the Mono Lake calcium towers. It is on the plugs, white and hard, like tooth tartar, and makes the surface of the floats kind of gray and dull looking.

Three Yamaha mechanics, besides the one that actually has the parts in his hand have agreed, it is due to water in the fuel, and probably mostly formed when the boat sat for 9-11 months prior to our purchase, and that using it has loosened up the deposits and now they are breaking off and plugging the small passage ways.

Cause, three fold: Lack off enough use, modern fuel changes, (more alcohol that attracts moisture) and need for fuel stabilizer year around.

Cure: Clean the whole, disassembled carb, run stabilizer, and run (as in USE THE BOAT) frequently. Check the Racor filters regularly, only run the carbs out of gas for over winter storage.

Cost: A new carb kit is about $105, and a new carb is about $350 each(x3 per engine) and cleaning with R&R and making it all look clean and shinny, $pricele$$, or in this case around $3-400. Yikes, now I know my wife really loves me.

Harvey
SleepyC :moon
 
Check the fuel tank vent holes to ensure they are not facing forward and picking up water when the boat is operated. Water in the fuel is bad. Salt water in the fuel is worse. Not sure when they changed, but the newer boats fuel tank vents are mounted above the rub rail. I assume because of this small problem. Now is a good time to learn to clean carbs and the fuel tanks and save some $$$.

I was wondering about your fuel system. Does each engine run off it's own tank? Or can you switch tanks and run both engines off one tank?
 
Thanks Chris, the fuel tank vents are above the rub rail. The tanks run through individual Rocar water/fuel separators and each side is individually isolated, port tank to port filter to port engine. thanks for the encouragement. when I looked at that stack of little parts, I am pretty over-whelmed, and although it might be less expensive if I did it, I would like to go boating again before I retire and I prefer it to run reliably when I go, so, I guess, I have to trust the mechanics and learn to do the best preventive maintenance I can.

Oh, the Real good thing about this, and the advice that the mechanic gave that is worth every penny, and he promised to put it in writing so that I could show my wife, and take it to work and show my boss.........., yup, he said, "Take the boat out more, use it more often" and there's no extra charge for that really great advice. He also said to use quality (what ever that is) fuel conditioners and additives.

Harvey
SleepyC :moon
 
Glad to hear your back running again. Good advise on the frequent usage! Anytime you find water in the filters you can easily drain each of the carb float bowls into a small container for moisture and dirt inspection. The carbs are vented, so when you rinse the salt from the engines there is always a small chance of moisture. But don't let that stop you from a good rinse if you run in the salt. Usually it enters thru the fuel passages.

I always recommend a maintenance manual and learning the basic carb cleaning. Maybe practice on your lawn mower carb first. Your local library probably has a manual for most small engines. With a carbed engine, sooner or later the task will be required.
 
Thank you, I am always a bit hesitant to spray the OB's down to heavily, but do scrub with a wet brush to get the salt off, and yes, so far we have not been anywhere but salt chuck. Do have hopes of making it to Lake Washington and Chelan this year though.

Of Interest to me, the mechanics explination of how the carberator cleaner worked, (used as a spray, into the airflow while the engine is running), is that the spray goes whipping through the intake ports, and down into the cylinder and has neither the time to do any cleaning in the carberator, nor does it get down into the bowl and float area and passages where this deposit was accumulating to clean there either.

Speaking of lawn mowers, boy am I glad it rains every weekend here, and that the C-Dory has a heated cabin :smile
Harvey
SleepyC :moon
 
Don't toss out the spray carb cleaner yet. Without going into a lot of detail: All carbs basically have two types of passage ways. They are either passage ways for fuel to travel. IE: idle circuit, main (high speed) jet, maybe an accelerator circuit, and a cold start or inrichment circuit. The other passages ways are air vents to the atmoshphere. Without the air vents the fuel can't be drawn up the correct passage way. Having fuel varnish, spider webs, mud dobbers or salt/water build up any of these passageways (air or fuel) is going to result in poor engine operation. If you don't use the cold start enrichment, over time it can gel and not function well when you really need it.

As you mentioned when the spray cleaner is used it does clean the intake air flow path mainly. Per the instructions most sprays recommend a liberal spray in the intake and let it soak prior to spraying with the engine running. Use caution against filling the combustion chambers with a large amount of liquid as this can cause damage on start up. It is also good for blasting out the tiny air passages as well as the throttle plates. If you look in the carb intake with a good light you should see a micro tiny passage way. Just one example of a place the spray with the plastic tube is used to clean.

For cleaning everywhere the fuel travels from the fuel tank, selector valve, needle valve to fill the float bowl, the idle circuit, the high speed circuit and the enrichment circuit and the carbon on the valves and combustion chamber/spark plugs you add the cleaner to the fuel tank.

Lots of good products out there. I don't have stock in the company but this stuff works good. Berrymans B-12 Chemtool. The second can down from the top.

http://www.berrymanproducts.com/Default.aspx?tabid=140

I emailed the engineer and confirmed, safe for boats, both two and four cycle. You can get the stuff at Walmart or Autozone. About $3 a can. It is in a metal can for a reason. The solvents are too strong for a plastic bottle in undiluted form so don't spill it. When mixed properly it is safe for plastic fuel tanks.

Try a bottle once in a while for trouble free operation. Especially the first tank in the spring. And one of the last tanks of the season. Along with Stabil fuel conditioner in every tank. Sometimes when the carbs are dirty and then a good cleaner is used the loosened crud just adds to the problem. So keeping them clean is the secret.
 
I store my gas with "engine stor" - fuel stablizer all winter- Can you then put in the berrymen carb cleaner in your tanks with the engine stor - also are you convinced that the berrymen carb cleaner and the engine stor provide different functions?

Thanks for your opinion.
Ken
 
Ken,

There should not be a problem with mixing. But for the best performance use the B-12 before the stabil if you can. The fuel stabilizer primarily keeps the fuel from breaking down over time. And keeping it in the tank over the winter is what it is designed for. The fuel varnish begins to build as fuel breaks down and evaporates. This happens every time an engine sits for awhile as the carbs are vented to the atmosphere. This is one advantage of fuel injected engines. Less evaporation, less fuel troubles. Carb'd engines that get ran often usually don't have fuel issues.

Some recommend that you don't run the carbs dry after a trip. If you run them dry (they never get completely dry) the small amount of fuel remaining in the fuel bowls evaporates quicker since there is less of it. Especially when that engine/carbs are hot and you run'em dry and shut her down. Speeding up the varnish process. If you leave the carbs full of fuel with stabilizer you might fair better between runs. I have heard of a few complaints of people having problems after using stabil. I think this is why. I also think that once varnish film starts, it tends to build on itself.

The B-12 has a host of solvents designed to remove varnish build up on the fuel passageways. Again, this stuff is in a metal can for a reason. Stabil is in a plastic bottle. B-12 is Strong Stuff. If you look up the material safety data sheet (MSDS) on the website you can see a host of solvents used in the B-12. The one I am most familiar with is the MEK. Methyl ethel ketone is a great solvent at dissolving all kinds of stuff. And the EPA frowns on the stuff. Can't believe it is still on the market.

I store my tanks with the minimum fuel stabil mix over the winter. The first tank gets the B-12 chemtool mix 10 or 12 gallons per can with no stabilizer. I try to run the whole mix thru the first trip out. And burn up last years fuel. Then just use the stabil in every tank after that. It is also good to use B-12 periodically and then let it sit in the engine. While your boat is parked awaiting the next voyage that solvent is silently at work cleaning your carbs. Again, if you are going to burn the fuel with B-12 added in a few weeks time, I would skip the stabil for that tank. The advantage of usually using the stabil in every tank is that when ever you stop using the boat for any unplanned event the fuel system is always treated. Any sediment and moisture is going to collect in the float bowls so periodic draining and inspection is a good thing.
 
Over winter storage, if you are not running the boat every 2 weeks, should the tanks be stored full. (With Stabil for the full 50 gal) or do you store them at less than full and just be sure to add the appropriate amount of Stabil. Then you are saying that the full tanks need to be run out on the first run, (50 gal x 4 mpg = 200 or at least 10-12 hours) Like the mechanics said, "Take the boat out More" I( like the concept, just getting the time to comply is hard. Maybe I need to just say I need my boat run and open it to volunteers :roll:

Harvey
SleepyC :moon
 
Another source for fuel additives is the local Evinrude dealer.

Evinrude has a product known as "2 + 4". This is a fuel additive that stabilizes the gasoline for storage, or for use. It prevents water problems and prevents varnish in the fuel system. It too, comes in a metal can and can stain the fiberglass around the fuel fill, so use a funnel.

Another Evinrude product is "Engine Tuner". This is used to de-carbonize the inside of the combustion chamber and rings. It is made especially for 2-stroke motors. It comes in a spray can and is sprayed into the carbs with the motor running, then shut off the motor and allow to soak for an hour, and then run the motor for 5 min to clear. This stuff really works, it will dissolve the carbon from the top of a piston.

I don't own any stock in Evinrude, but I have used these products for years, and they do work.
 
Harvey,

When fuel tanks were made of steel they were kept full to minimize the air pocket at the top of the tank. The fuel and steel tank would condensate as the temperature changed and with the air cause rust and sediment. And you had the fuel going bad with age.

With the plastic tank I won't say that they don't condensate because moisture is always in the air, but I don't think it is as bad as the cold steel tank. Plastic tanks don't rust. So the main problems with long term storage is the fuel going bad. Hard to tell so use a fuel stabilizer. And moisture. The fuel stabilizer should help with the moisture. If moisture accumulates in any great quanity it will form droplets and sink to the lowest area. If you pull a fuel tank you might see it there since the fuel tanks never run dry. Drain the water filter separator and might see some. Drain the carb float bowls and you might find some. Most engines have a last chance filter under the engine cover made of white plastic. All you can see is if liquid is present. You can get an after market clear filter. Then you can see fuel, water droplets or sediment. The point here is if you have moisture in any quantity you can see it and deal with it.

With the fuel tanks, when I stop using my boat for the season the stabil/fuel mix is always present. I eventually syphon as much fuel as I can out and run it in the garden tractor, car, truck and such. I can never get the last two gallons or so out, but the stabil treatment is there. In the spring I mix a can of B-12 with (can't remember if it's 10 or 12 gallons) and dump that in one tank and run it thru the first trip of the season. The other tank has about 10 gallons of fresh fuel with stabil. The idea of not filling the tanks all the way is to try and purge out the older fuel that was in the bottom of the tanks. It is a little work to syphon the fuel each year. I like this way better than buying and treating 50 gallons, storing all season and then burning it up in the spring. Now days they have the winter blended fuel and the summer blend. Who really knows when the change? Maybe it's a moot point but something to consider. If you top the tanks in the fall are you burning winter blend in the spring? Maybe it doesn't matter... I'm sure other folks do things different but this method has worked well for me.

I don't get the time to do much coastal cruising. Therefor I almost always fill my boat six gallons cans at a time. This allows inspection of the cans each time for dirt and moisture. Most gas stations are better at moisture dirt control than marina fuel. I just use one of those plastic syphon pumps that you squeeze to get it going. Had the same pump since 1989 and it hasn't failed yet.

One more thing: When you see that tanker truck filling up the gas station. Don't get gas there. It takes several hours for the sediment and moisture in those big tanks to settle back to the bottom after the tanker stirs it all up.
 
WOW, thanks for all the info. I have plastic, somewhat translucent, tanks that I can see the fuel level through. I have checked the Racors, but will now do that every trip out. And change the filter inside the cowl to a clear one. I have "Ring-Free" a Yamaha product, that the mechanics say works great. I need to get some of the B-12 and start using that. I use a product called CorrosionEX to spray inside the cowling to keep corrosion down. Seems to be working on the outside anyway.

Larry, Thanks for the tip on the "2+4" stabilizer. I will look that up locally.

Harvey
SleepyC :moon
 
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