Would You Buy Another Tohatsu??

[1affiah]

Well, a pressurized crankcase usually points to the head gasket. I don't know enough about 4 stroke OB's, but my old 2-stroke Tohatsu 8 was bulletproof.

[lovinlifebda]

Another satisfied Tohatsu owner. The two stroke 9.8, bought it about 5 years ago. We are full time and it gets used a lot, no fancy gas down here in the Caribbean so that could be a factor. If it doesn’t start on the first pull it was because my first effort was a bit wimpy.

[Bill O]

Like the Tohatsu brand also. Generally run 2 strokes and find them much easy to maintain. The carb jetting is larger w/the 2S and don't get clogged/less finicky than the 4S.

[Stewie12]

I ran the smallest Tohatsu on my dingy for years. It was the model that did not have a reverse gear, you turned the motor around. Never had a single problem with it and I would buy Tohatsu again.

[Peregrine1983]

I had a 2015 Tohatsu 9.8 that was such an incredible nightmare to own it made me want to throw it overboard. I had the carb rebuilt and cleaned 5+ times. They are making and selling motors that are simply not reliable at all on US gasoline with ethanol.


EDIT: I bought a 2003 Mercury 5 hp that has been absolutely excellent on both ethanol and non-ethanol gas, though I try to only run non-ethanol through it. Love the motor.



To the OP, I would cut your losses and buy a used Mercury or Yamaha.

[Bibster]

I have an electric-start 9.8 Tohatsu 4-stroke in my Cape Dory 26 and that thing runs like a champ. I moved my boat from Annapolis, MD to southwest Florida via the ICW, approximately 1300 miles, and 95 percent of that was under motor. I never had a problem until the end of our crossing of Lake Okeechobee, when the engine stalled out and then ran roughly after I restarted it. I changed the fuel filter and the problem was solved. I also had to replace the starter last year, but outside of those two issues, it has run perfectly. By the way, I have never run ethanol gas through that motor.

[a64pilot]

You can’t really pressurize a crankcase, the crankcase vent wont let that happen, so it must be clogged, or more likely the level was above the dip stick tube.
My money is the water in the oil is from the overheating, and as I’m sure Tohatsu doesn’t manufacture their own thermostats, it’s hard to blame them, and or think a different model of engine would matter.
My guess is head gasket.

Many small motors just don’t seem to have issues with alcohol, Honda generators for instance don’t seem to?
I think putting an honest high quality fuel filter on just before the engine helps, I have a Racor on my dinghy, it’s a bigger fuel injected motor but I still think making sure the motor only gets clean water free fuel is important.

[Ken Pole]

Gave up on conventional outboards; Lehr propane altenative a treat in terms of fuel availability and consumption as well as storage.

[zstine]

I bought my Tohatsu 9.8 in 2013 and the only problem I have had was a fuel pump, which results in gas getting in the oil. Easy to fix. I'm pretty happy with it.

[Lake-Effect]

Originally Posted by Chotu

What are the possible ways water can get into the lube oil?

If the engine overheated enough to seize , you possibly warped the head and/or blew the head gasket. less likely that you cracked anything... but not impossible.

I, uh, overheated and warped the head in my small truck once.

If you can find a kindly old outboard mechanic with a machine shop, it's not a tremendously hard fix, but might not be cost-effective.

Is this maybe because I ran with no thermostat?

No

... why was the oil/water in the crankcase so pressurized, it sprayed out at me pulling the dipstick?

Because if there's water circulating with the oil, it's turning to steam. That's the pressure.

[Chotu]

Originally Posted by Ken Pole

Gave up on conventional outboards; Lehr propane altenative a treat in terms of fuel availability and consumption as well as storage.

I had one of these that came with the boat. We used it last season and it was reliable as can be. No prayer of clogging that carburetor.

A couple issues with these though:

1) they are cheaply made. The transom bolts seized and could not be loosened from the dinghy after only a few months. After cranking them hard enough to twist them like pretzels, I cut them off.

2) unless you have a BBQ tank in your dinghy, the range is awful on those wasteful small 1lb tanks. Never failed to leave me in the middle of the channel at night when running out of propane.

I think the Lehr is great for situations where you don’t want to row, but you almost could have because it’s close. I anchor way, way out and have very long rides. It’s not really up to that task.

I also no longer have a Lehr because it was stolen by none other than Davey Jones. We had category 1 hurricane force winds for an evening in Long Island this spring. Thanks to those cheap transom bolts being cut off last year, it was on the stern outboard mounting plate on the aft pulpit. There was a lot of wind and a line got caught on the outboard. Pulled it off the mounting plate and into the water. Bye bye.

[Chotu]

Originally Posted by Lake-Effect

If the engine overheated enough to seize , you possibly warped the head and/or blew the head gasket. less likely that you cracked anything... but not impossible.

I, uh, overheated and warped the head in my small truck once.

If you can find a kindly old outboard mechanic with a machine shop, it's not a tremendously hard fix, but might not be cost-effective.

No


Because if there's water circulating with the oil, it's turning to steam. That's the pressure.

Wow! That’s a very concise and helpful post. Thank you

Seems quite reasonable to guess this is what happened.

I would like to formally register a design flaw report.

A telltale should be located DOWNSTREAM of the thermostat in an outboard without instrumentation or a thermal shutdown sensor.

The fact that I can unknowingly be overheating to the point the engine seized and still have a telltale pushing a jet of water as hard as ever says to me Tohatsu sucks at engineering. Lol

[Bill O]

Originally Posted by Peregrine1983

I had a 2015 Tohatsu 9.8 that was such an incredible nightmare to own it made me want to throw it overboard. I had the carb rebuilt and cleaned 5+ times. They are making and selling motors that are simply not reliable at all on US gasoline with ethanol.


EDIT: I bought a 2003 Mercury 5 hp that has been absolutely excellent on both ethanol and non-ethanol gas, though I try to only run non-ethanol through it. Love the motor.



To the OP, I would cut your losses and buy a used Mercury or Yamaha.

The Mercury 5 hp is a Tohatsu motor.

[Lake-Effect]

Originally Posted by Ken Pole

Gave up on conventional outboards; Lehr propane altenative a treat in terms of fuel availability and consumption as well as storage.

How long have you had your Lehr, and how would you compare the fuel cost to gas? Much of a hassle lugging propane tanks around?

[Gerry Connolly]

It's pretty obvious that your head gasket failed, hence the water in the oil and the milky color. Might need a carb kit and a carb overhaul as well. Probably at least a $500 job depending on where you are.