Seafoam has nowhere to go?

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Bronco99

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I wanted to flush out my Honda BF15 outboard due to dirty fuel in the system so due to being a continuous cruiser I added the seafoam to the tank, gave it some revs and waited for the plumes of smoke.

My question is, because nothing happened, does that mean that due to the prop being semi submerged the decarb smoke had no clear outlet, and would this have done any damage?
 
What Seafoam : petrol ratio did you use

This is the procedure described on the iBoats forum( sorry about the dinosaur units)
First you need a separate small fuel tank
You'll need 3/4 US gallon of gasoline and one 16oz can of Seafoam for each engine. (Don't forget to add 3oz of oil if you are pre-mixing in a carbed two stroke engine). Use a 3 ft piece of fuel hose off the small tank. Connect this tank to your engine by pulling off the main tank fuel hose from the intake side of your water separating fuel filter and plug the hose off the small tank onto that fitting. Or you can separate the fuel line on the tank side primer ball, so you can still use your primer. If your engine has a fuel plug then you will also need a fuel plug on the smaller tank's hose.
Start the engine, let it warm up and start pulling the mix into the engine. You may have to increase the idle to keep it running once she gets loaded with the Seafoam. Run the engine 15 minutes at the dock or just cruising around under 2500 rpm's. Then shut it down and let it sit for another 15 minutes.
Restart the engine; the smoke you see is the carbon burning off. Do the whole thing again and let her sit again for 15 more minutes. If she smokes after the second time do it again.
 
VicS said:
What Seafoam : petrol ratio did you use

This is the procedure described on the iBoats forum( sorry about the dinosaur units)
First you need a separate small fuel tank
You'll need 3/4 US gallon of gasoline and one 16oz can of Seafoam for each engine. (Don't forget to add 3oz of oil if you are pre-mixing in a carbed two stroke engine). Use a 3 ft piece of fuel hose off the small tank. Connect this tank to your engine by pulling off the main tank fuel hose from the intake side of your water separating fuel filter and plug the hose off the small tank onto that fitting. Or you can separate the fuel line on the tank side primer ball, so you can still use your primer. If your engine has a fuel plug then you will also need a fuel plug on the smaller tank's hose.
Start the engine, let it warm up and start pulling the mix into the engine. You may have to increase the idle to keep it running once she gets loaded with the Seafoam. Run the engine 15 minutes at the dock or just cruising around under 2500 rpm's. Then shut it down and let it sit for another 15 minutes.
Restart the engine; the smoke you see is the carbon burning off. Do the whole thing again and let her sit again for 15 more minutes. If she smokes after the second time do it again.
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First thanks for the answer. My BF15 doesn't have an engine tank, I connect my fuel line straight to an external tank. I put 2 litres of fuel in this tank and added half the 16 Oz bottle of Seafoam. Followed the procedure. No result.
 
Hi Bronco99, i used seafoam on my Tohatsu 8hp 2 stroke outboard. The outboard was running a bit rough and would stop if i turned the throttle fown to idle, i think this due to not using the engine for 2 years. I too had an external fuel tank. What i did was put 5 litres of fuel in the tank plus 100ml of 2 stroke oil ( being a 2 stroke engine with 50:1 ratio ) and i emptied the whole bottle of seafoam into the tank. I then ran the engine in a dustbin of water for 20 minutes. I then turned the engine off and let it sit for 30 minutes. I then fired up the engine and let it run for quite a while. It was at this last stage that i got a lot of smoke out from the exhaust and also minute black particles came out. The engine ran like new after the treatment. I hope this will be of some help to you. Best regards, Oz.
 
Bronco99 said:
I wanted to flush out my Honda BF15 outboard due to dirty fuel in the system so due to being a continuous cruiser I added the seafoam to the tank, gave it some revs and waited for the plumes of smoke.

My question is, because nothing happened, does that mean that due to the prop being semi submerged the decarb smoke had no clear outlet, and would this have done any damage?
Click to expand...
I always thought that the best results were supposedly obtained by using Seafoam spray and introducing the spray directly into the air intake.

Whether it does any good is a moot point, although my starting point would be not to trust any product which says that it can be added to the oil or the fuel. :unsure:

The famed "white smoke" is more likely to be the Seafoam itself burning off than anything else ..... but it's good marketing.

Richard
 
Hi RichardS, you are indeed right that the seafoam can be sprayed directly into the air intake, this being one way of using it. The tin has instructions to this effect as well as instructions for using it as i did. Whether it is snake oil, all i can say is it worked with my engine. All the best. Oz.
 
oz-1 said:
Hi Bronco99, i used seafoam on my Tohatsu 8hp 2 stroke outboard. The outboard was running a bit rough and would stop if i turned the throttle fown to idle, i think this due to not using the engine for 2 years. I too had an external fuel tank. What i did was put 5 litres of fuel in the tank plus 100ml of 2 stroke oil ( being a 2 stroke engine with 50:1 ratio ) and i emptied the whole bottle of seafoam into the tank. I then ran the engine in a dustbin of water for 20 minutes. I then turned the engine off and let it sit for 30 minutes. I then fired up the engine and let it run for quite a while. It was at this last stage that i got a lot of smoke out from the exhaust and also minute black particles came out. The engine ran like new after the treatment. I hope this will be of some help to you. Best regards, Oz.
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Hi Oz, I pretty much did what you did. To be more accurate I ran the mix from a green billy can first to prioritise the engine rather than the dirty tank. I idled with intermittent revs for 15 mins then rested then ran again for a while, rested then added the remaining mix to the main external tank to clean that out. Cruised briefly 100m up & down the cut. No white smoke to be seen! Perhaps my mechanics phone diagnosis was wrong and the sawing sound and reluctant throttle isn't dirt in the fuel system/carb but the filters/plugs. Or something else. :unsure:
 
So I checked the engine manual and the exhaust comes through the prop. Does this mean that the prop/exhaust needs to be clear of the water for the seafoam to escape? If so do I need to connect a hose to allow water to run through the motor while it runs?
 
Bronco99 said:
So I checked the engine manual and the exhaust comes through the prop. Does this mean that the prop/exhaust needs to be clear of the water for the seafoam to escape? If so do I need to connect a hose to allow water to run through the motor while it runs?
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The Seafoam burns in the combustion chamber along with the fuel and exits through the exhaust ports in the normal way.

You don't need to do anything special with the version you have, other than add it to the fuel or oil. However, I suspect that you are thinking that Seafoam is some kind of miracle cure-all with special properties when many of us in the spannering community would observe that it is snake oil and is most likely to do nothing at all, except smoke a lot .... and then not always that. :)

I have seen photos taken inside cylinders before and after Seafoam treatment. :(

Richard
 
Most of the smoke is from the Seafoam burning smoky. That is what it does if strong. What makes people believe that is a good thing? Very little of what you see is deposits coming loose. Just use it at standard dose and you'll be fine.

The cure for a dirty carb is manual cleaning. Not hard, works every time, if attension is paid to details... which too often it is not.
 
thinwater said:
Most of the smoke is from the Seafoam burning smoky. That is what it does if strong. What makes people believe that is a good thing? Very little of what you see is deposits coming loose. Just use it at standard dose and you'll be fine.

The cure for a dirty carb is manual cleaning. Not hard, works every time, if attension is paid to details... which too often it is not.
Click to expand...
Thanks. Just wish I had a mechanic friend who could show me how to do that ?
 
Bronco99 said:
Thanks. Just wish I had a mechanic friend who could show me how to do that ?
Click to expand...

The carb usually comes off with 2 bolts disconnecting 2 hoses, and unclipping throttle and sometimes choke. Easy.

Flip it over and take the bowl off (2 screws). Consulting the parts breakdown, find the main and idle jets and screw them out (locations vary). You should be able to see light through the hole (tiny), but if not, find the tiniest wire you can (fine wire brush) and gently poke it out (or replace). Clean everything , particularly the passages and needle valve seat, with spray carb cleaner. Put the jets back in.

Google it. Watch a video. Not hard. About 15 minutes if you've done it before.
 
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