"Rehabilitation" of a 5-hp Tohatsu 4-stroke that went to the bottom

Jul 27, 2011
5,002
Bavaria 38E Alamitos Bay
A strange event occurred the evening of July 3rd that sent my 5-hp Tohatsu 4-stroke to the sea bottom at my slip, to about 12 ft of depth. It was recovered using SCUBA the next morning, July 4th. Of course, we all "know" that the thing should be taken to a service facility immediately, or else "pickled." I can assure everyone that no Tohatsu service center was open on July 4th around Long Beach. In fact, not until Monday, July 10, as it would have worked out for me. So that left me with a DIY rescue of the outboard, although not really being equipped at home with the "facilities" to saturate the thing w/diesel fuel after several flushes, etc.

Nevertheless, I rinsed it thoroughly with the shroud cover removed, changed the motor oil several times, drained the carburetor and flushed it with clean gasoline, purged the fuel filter similarly, removed the one spark plug and saturated/rinsed the cylinder repeatedly w/WD-40. And, after a couple of days, fired the thing off where it "ran" for a second or two then quit. I was very happy to get it to start at all considering the gloomy forecast one reads on the internet if it is not taken to a service center soon after first "pickling" it.

By July 19 I was finally able to take it to an authorized Tohatsu service center in Costa Mesa where they replaced the carburetor, the fuel filter, and the air box; changed the motor oil and gear oil again, installed a new spark plug, and got it "running." But I still had difficulty with it running very well even after several outings in the dink on the Bay. I decided it would probably never run even as well as it did b/f it went to the bottom which, frankly, was not all that well--a 2000 model year.

BUT--due to my frequent reading of the postings of the folks here on SBO, I decided to try some of the EtOH-free "super fuel" that I've read mentioned to see what would happen. There's one place in So. Cal. where you can buy this stuff--Westminster, which is near Long Beach. I bought VP C9. A 96-octane, ethanol-free, non-oxygenated, unleaded gasoline. :wow3: :wow3:

I ran the outboard today in the tank and the difference is NOTICEABLE. The engine would actually idle at a nearly zero throttle. I have not seen that for a while. Great stuff, but--you guessed it--$64 for a 5-gal container full:yikes:. Can't wait to try it out on the Bay.

I'd love to use it from now on--but...:doh:...$$!!

KG

https://www.race-dezert.com/home/vp-introduces-c9-for-performance-seasonal-storage-22137.html
 
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Gunni

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Mar 16, 2010
5,937
Beneteau 411 Oceanis Annapolis
Notice they refer to the stuff as fuel. They blend a mix of stuff to approximate gasoline, so it is really a synthetic. As long as you are experimenting, toss a can of Seafoam in a tank of fresh gasoline, I was skeptical when the john boat guys suggested it but wow, it actually smoothed my low speed idle problem.
 

Rick D

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Jun 14, 2008
7,139
Hunter Legend 40.5 Shoreline Marina Long Beach CA
Thanks for the lead on the fuel. Is that the one near the 405 & 110?
 
Dec 31, 2016
319
Beneteau Oceanis 351 Charlottetown
Notice they refer to the stuff as fuel. They blend a mix of stuff to approximate gasoline, so it is really a synthetic. As long as you are experimenting, toss a can of Seafoam in a tank of fresh gasoline, I was skeptical when the john boat guys suggested it but wow, it actually smoothed my low speed idle problem.
I have to agree on the Seafoam I had good results with a carb problem, and I'm not even a believer on a-fix-in-a-can stuff!
 
Oct 22, 2014
21,104
CAL 35 Cruiser #21 moored EVERETT WA
So what is this Seafoam? And what exactly is it supposed to do?

See it sold in Auto parts stores.
 
Jul 27, 2011
5,002
Bavaria 38E Alamitos Bay
Thanks for the lead on the fuel. Is that the one near the 405 & 110?
It's off the Garden Grove freeway--22. Something like 9-10 miles from Seal Beach.

SOCAL Nitrous & Racing Fuels
7216 Garden Grove Blvd
Westminster, CA 92683
714-622-5093

It's very cryptically located. Once finding the street address you have to go around to the back of the building where they open a warehouse door and sell out of there. Good service.
 
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Rick D

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Jun 14, 2008
7,139
Hunter Legend 40.5 Shoreline Marina Long Beach CA
It's very cryptically located. Once finding the street address you have to go around to the back of the building where they open a warehouse door and sell out of there. Good service.
Sounds like I need to go buy it with sunglasses and a hoodie! Thanks for the lead.
 

NYSail

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Jan 6, 2006
3,064
Beneteau 423 Mt. Sinai, NY
Seafoam is great stuff. I usually fill half the bowl on my racor up with it then top off with diesel when doing filter change. Cleans injectors and smooths performance.
 

JRT

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Feb 14, 2017
2,048
Catalina 310 211 Lake Guntersville, AL
Can you get 100% gasoline instead, no ethanol? I like the results with the 2 Tohatsu motors I've had.
 
Mar 29, 2017
576
Hunter 30t 9805 littlecreek
$64. Will you even burn up 5 gal of fuel in a year. For what I use my dink for good fuel is well worth $100 a year in good fuel. It's nice to know the motor will start right up when ya need it
 

jviss

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Feb 5, 2004
6,745
Tartan 3800 20 Westport, MA
$64. Will you even burn up 5 gal of fuel in a year. For what I use my dink for good fuel is well worth $100 a year in good fuel. It's nice to know the motor will start right up when ya need it
I do. I have a 15HP 2-stroke, and not the most fuel efficient thing on the planet, I guess.

However, once I got rid of the Mercury OEM plastic fuel tank, which had E10 susceptible components, and switched to a NOS metal tank, I've had zero problems with fuel. I must confess I buy at the marina, and I don't know if it has ethanol or not; I'll check this weekend.

I try to keep the tank full over the winter, and if I think of it add a dash of STA-BIL. In the spring I check for water in the tank, by pushing open the motor-side quick disconnect valve and siphoning into a glass jar. This year there was no water.

The components in the motor seem O.K., it was just the tank.
 
Jul 27, 2011
5,002
Bavaria 38E Alamitos Bay
$64. Will you even burn up 5 gal of fuel in a year. For what I use my dink for good fuel is well worth $100 a year in good fuel. It's nice to know the motor will start right up when ya need it
Not typically. But lately I’ve been using the dink more tootling around Alamitos Bay, etc. But, you’re right.
 

pateco

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Aug 12, 2014
2,207
Hunter 31 (1983) Pompano Beach FL
How to clean diesel injectors with Seafoam Motor Treatment