Yamalube Combustion Chamber Cleaner Spray

[AK115V4-93]

Hi all,

After some advice regarding removing engine deposits / decarboning / internal cleaning.

I’ve recently acquired a 1993 115HP V4 Yamaha outboard (model 6E5 - long leg - 115BET) that looks to be in excellent shape for its age cosmetically (hours unknown). It starts easily and idles well on hose muffs in the driveway but I am yet to put it into the water to give it an actual run.

I was planning to run a ring free shock treatment in the first tank of fuel when I take it out in the next month but I was told by my Yamaha marine dealer service department not to waste money on ring free and use a can of Yamalube Combustion Chamber Cleaner instead as its far more effective than a ring free shock treatment.

The service department of the dealership told me they always use the Yamalube Combustion Chamber Cleaner when they service customers boats and to use it by:
• Spraying directly into the each of the carbie throats for 4 seconds while running at 1100 RPM
• Then letting it run for a few minutes
• Spray again until ½ the can is used and shut off the motor straight away
• Let it sit overnight
• Run the engine at medium load in the lake for about 10 minutes to finish.
• Repeat every 200 hours

As I don’t know the history of this outboard and with it being 22 years old, would you recommend me getting a can of Combustion Chamber Cleaner and using it? My aim is to look after and keep the engine in top shape.

This won’t cause any damage would it? I’ve read people are worried hard prices of carbon could break off and scratch up the cylinder etc.

[robert graham]

After you establish that the motor runs well in the river under load, easy starting, good idle, smooth mid-range and wide open throttle, then run some Ringfree through it at "decarbonize dosage" for a tank of fuel, then run the Ringfree at "maintain dosage"from then on.....should be good to go!....

[TownsendsFJR1300]

Just as a side note, the RF shock treatment is TWICE than normal use...

I did a bunch of research including calling Mama Yamaha in Ca to find out (as its NOT listed on the can).


I don't see the main procedure in your post being a problem.

If that product can loosen it up enough to come off, the carbon should be pretty soft.

[AK115V4-93]

After you establish that the motor runs well in the river under load, easy starting, good idle, smooth mid-range and wide open throttle, then run some Ringfree through it at "decarbonize dosage" for a tank of fuel, then run the Ringfree at "maintain dosage"from then on.....should be good to go!....

That’s what I’ve read on the internet also Robert, but the Yamaha service manager said they don’t sell much ringfree and instead handed me a can of Yamalube Combustion Chamber Cleaner instead telling me its a better way.

Just as a side note, the RF shock treatment is TWICE than normal use...

I did a bunch of research including calling Mama Yamaha in Ca to find out (as its NOT listed on the can).


I don't see the main procedure in your post being a problem.

If that product can loosen it up enough to come off, the carbon should be pretty soft.

Ok perhaps I should spray Yamalube Combustion Chamber Cleaner as detailed above for a first stage, then later on do a ring free shock treatment after a few runs to finish the treatment?

Logically I agree with your soft carbon statement.

I just hope the Combustion Chamber Cleaner not going to damage anything due to the motor being 22 years old. I doubt it’s ever been decarbed.
Interestingly they said leave it overnight, but the can says 30 mins to an hour. Just hope it won’t attack the engine internally!

Should I even bother with all this? Kind of conflicted here! I just want to ensure my engine lasts as long as possible.

[TownsendsFJR1300]

I'd peek down the spark plug hole and check for excessive carbon deposits atop the piston.

Also, remember, carbon WILL build up in-between the piston rings and piston over time / use. And you CANNOT see it without pulling the piston.

Now, a leak down test will give you an idea of the health of the engine and you can physically check how much leakage is going past the rings.

I use RF in EVERY GAS ENGINE I own, every one. EXCELLENT PRODUCT..

IMO, I'd do the chamber cleaner EXACTLY per the directions, then simply run RF regularly...

As posted above, I'd do the leak down test BEFORE and then after, just to see the results, etc.


**Also, the combustion chamber cleaner does JUST THAT. RF, does that (I would think NOT as efficiently) BUT also cleans the entire fuel system. With today's crappy gas, its about mandatory...

[AK115V4-93]

Update

Update:
I performed the Combustion Chamber Cleaner as per the instructions on the can, spraying 10 second intervals into each carbie throat (As per can directions, 10 seconds per 100cc of engine displacement).

I did this 4 times to give each cylinder 40 seconds of treatment at a fast idle (1200 RPM) - for the 10 sec/100cc instruction. Engine was at temperature before treatment.

I then repeated the above procedure after letting the engine run for about 1 minute between treatments at which point I shut it down at let it sit for 1 hour.

After 1 hour I put it into the river and ran it at no more than 2500RPM for 20 minutes to burn off the solution.

While the smell of methanol was strong for a while from the solution, I didn’t really see any black sludge or anything of the sort that others reported. No large amount of smoke either. I conclude the engine was decently clean inside before the treatment.

After some WOT running and general cruising I added a decarb amount of Ring Free (12 FL OZ/355ml of Ring free to 6 Gallons/22 litres of fuel) to a portable tank and ran that through.

No issues so far. All appears well. Compression figures did not change after the treatment.

[TownsendsFJR1300]

Sounds like your engine was pretty clean to start with (as long as your compression #'s are close to each other).


Your procedure sounds almost exactly the same used with a product Evinrude used to (and may still sell) which I used on a 140 looper MANY years ago...

Not sure if posted, RF is NOT a stabilizer. Regular, normal amount use (1 oz / 10 gallons) will help keep the fuel system clean as well, not just the top end.

But I've found either "Gas Shok", K100 or Yamaha makes a stabilizer (never used it) is mandatory(especially for carbed engines)

Thanks for the updates too. Safe boating!

[AK115V4-93]

Yes, based on what I saw, I assume it was rather clean which is nice. Compression values are no lower than 2 psi than the highest value (127 psi) across the board.

I add Stabil Marine as a fuel stabiliser to every tank and I run ringfree in every 5 tanks as it’s rather expensive in Australia. Our fuel is rather good also and ethanol free 91 octane is standard where I live. I have to actually look hard if I want to find a station selling ethanol. I also run a Racor style water separator fuel filter. I hope this will keep the Yamaha happy for many years. Just gave it new plugs also the other day.

[TownsendsFJR1300]

Wish we'd eat corn instead of making "fuel" like most other countries...

Without the ethanol, you should be good with your current mix..

[99yam40]

not sure I would want to pay the price they pay down there for fuel.
but I do not know what they are paying right now

[TownsendsFJR1300]

not sure I would want to pay the price they pay down there for fuel.
but I do not know what they are paying right now

Great question!

AK, can you give us the price of regular fuel US dollors / gallon (liters and pounds ((or)) would get lost in translation).


And from what I've read years ago when ethonol "popped up", it costs more to manufacture than non-ethonol. Advances in science may have changed that (kinda doubt it)

[99yam40]

If the government would stop subsidizing the ethanol fuel I believe it would not be made.

I am sure by the time you count the fuel needed to plow, plant, harvest, then shred the fields along with dry and store ,transport the corn, grind,mash, and ferment and distill.
and then store and transport the ethanol and then blend it, because you have already used more fuel(energy) to make this stuff than you get out of it

It would be a lot cheaper to just use the fossil fuel by itself

[TownsendsFJR1300]

plus 10000 ^^^^^^

[AK115V4-93]

not sure I would want to pay the price they pay down there for fuel.
but I do not know what they are paying right now

Great question!

AK, can you give us the price of regular fuel US dollors / gallon (liters and pounds ((or)) would get lost in translation).


And from what I've read years ago when ethonol "popped up", it costs more to manufacture than non-ethonol. Advances in science may have changed that (kinda doubt it)

For sure - so in Australian terms, today my local fuel station is selling standard 91 unleaded fuel as such:

$1.30 AUD for 1 litre of 91 Octane Unleaded. Mind you on the cheap days we can see 1.00 AUD per litre. It doesn't really drop much below that.

Translated to US terms:
1.30 AUD = 0.97 USD
1 US Gallon = 3.78 Litres
So (0.97x3.78) $3.66 USD a gallon.

I think I did that right.

The other way in AUD - 1 gallon (3.78 litres) costing 1.30 AUD per litre X 3.78 litres = 4.91 AUD per gallon of fuel.

We have unleaded 91, 95 and 98 octane as well as 'E10 ethanol' and 'E85 ethanol' (E10 contains 10% ethanol content, E85 contains 70-85% ethanol content) and Liquid Petroleum Gas (LPG) aka propane.

[cpostis]

If the government would stop subsidizing the ethanol fuel I believe it would not be made.

I am sure by the time you count the fuel needed to plow, plant, harvest, then shred the fields along with dry and store ,transport the corn, grind,mash, and ferment and distill.
and then store and transport the ethanol and then blend it, because you have already used more fuel(energy) to make this stuff than you get out of it

It would be a lot cheaper to just use the fossil fuel by itself

Well, there is some good news and bad. The outgoing administration has lowered the requirement of percentage of "Bio-fuels" (including ethanol blends) that were established by the Clinton administration in 2007. However, our incoming administration is leaning towards increasing the percentage.

How much do you think big Agribusiness influences this?

Obama curbs ethanol in blow to corn growers - POLITICO

I have a good price at a local gas station for 90 octane non-ethanol @ $3.259 USD a gallon. Reg E-10 is $2.09 a gallon (I think 87 octane).