Would You Buy Another Tohatsu??

[a64pilot]

Originally Posted by jhulmer

Yeah, but I understand that racing engines are built to loose specs to avoid the worry of break-in. Punch-it go fast rebuild it again next week.

In building Kawasaki 900’s way back in the late 70’s, early 80’s we would hone the outer cylinders to .0005 (that’s a half a thousands) and the inner two to .0015 (thats 1.5 thousands) because the inner two ran hotter.
That’s at least as close as factory specs and we held a much tighter tolerance.
We would cut a 5 angle valve job with the valve seating at the extreme edge of the seat, and then take a die grinder and smooth the inner 4 cut angles, again much tighter tolerances.

Depending on the type of racing some clearances were opened up and or parts not installed in the theory of reducing drag to increase Hp like leaving oil control rings out. We never did because we tried and there was no more HP there, at least none we could measure, and as we were bike builders, a smoking engine wasn’t good advertising.
We went faster than almost every body else and held very tight tolerances.

[s/v Jedi]

Originally Posted by a64pilot

My starts on first pull was the sample of one, and I have looked in the Suzuki manual with no mention of two pulls, so it seems they differ in that respect, the Suzuki doesn’t need a pull to charge up or whatever

Happy to report that my EFI 20hp also starts in one pull. This is the 2020 Mercury labeled one.

I must say I now tried by pulling the cord out all the way. Before, I did the lazy pull while sitting

[a64pilot]

Originally Posted by s/v Jedi

Happy to report that my EFI 20hp also starts in one pull. This is the 2020 Mercury labeled one.

I must say I now tried by pulling the cord out all the way. Before, I did the lazy pull while sitting

What had me wondering is often times fuel and injection systems will be common among many different brands of engines, how many Diesels use Bosch injection pumps for example? I don’t think any small manufacturer makes their own.
So I wondered if Tohatsu and Suzuki shared the same fuel injection system, and if so then it’s likely they will act the same.
Of course, maybe they don’t too.

[s/v Jedi]

Originally Posted by a64pilot

What had me wondering is often times fuel and injection systems will be common among many different brands of engines, how many Diesels use Bosch injection pumps for example? I don’t think any small manufacturer makes their own.
So I wondered if Tohatsu and Suzuki shared the same fuel injection system, and if so then it’s likely they will act the same.
Of course, maybe they don’t too.

Comparing pictures... the clip securing the cowling, the metal supports for laying it on it’s side and many other items seem so identical that I think it’s the same outboard.

[a64pilot]

Could be, but I’m pretty sure Suzuki makes theirs, and it’s been out at least since 2014 when I bought mine.
The Tohatsu is I believe 5 lbs lighter too.

What is the Country of manufacture for yours? It may be on the data tag on the motor, the Suzuki is I think Singapore.
I’d be real surprised if Tohatsu buys it from Suzuki.

[s/v Jedi]

Originally Posted by a64pilot

Could be, but I’m pretty sure Suzuki makes theirs, and it’s been out at least since 2014 when I bought mine.
The Tohatsu is I believe 5 lbs lighter too.

What is the Country of manufacture for yours? It may be on the data tag on the motor, the Suzuki is I think Singapore.
I’d be real surprised if Tohatsu buys it from Suzuki.

I suspect Tohatsu may have bought a license...

[frozenhawaiian]

I have both a 2005 4hp and 2018 9.8hp EFI and both have been great. the 4ph actually got submerged when a superyacht wake flipped the dinghy when we were at anchor last year. mechanic pulled it apart and got the water out and it still run like a champ. my experience with outboard under 6hp is that no one brand seems to stand out from the rest.

[a64pilot]

Originally Posted by s/v Jedi

I suspect Tohatsu may have bought a license...

I could see them licensing the fuel injection or computer or similar, but to build the same outboard requires a but load of tooling.
It’s possible of course, but most companies do like Mercury does, buy a Tohatsu, maybe a few minor differences spec’d like the standard lifting ring and different stickers of course.

Maybe they just copied it too, it’s not like it’s patented I wouldn't think. But they also lost 5 lbs somehow. But I just looked, slightly different displacements and RPM range too, not much different though.

[Dockhead]

Originally Posted by a64pilot

What had me wondering is often times fuel and injection systems will be common among many different brands of engines, how many Diesels use Bosch injection pumps for example?

I think the Bosch injection systems are a worldwide monopoly for small diesels, aren't they? Even Zexel is owned by Bosch. Is there any other choice for a small diesel?

[a64pilot]

I’m sure there are others, I don’t see the Chinese using Bosch for example, and I’d expect that common rail will bring that monopoly to an end. Ford used a HEUI injector for example, which was everything in the injector, using oil pressure to pump fuel to very high pressure. Common rail has changed things, tremendously, it’s taken a diesels from the mechanical world to the digital one.

https://www.dieselhub.com/tech/heui.html

Common rail is the future, and I’m not so sure Bosch is still a leader in it, they may end up like Kodak.

I’m surprised in a way that mechanical injected engines are still around.

[chasfgr]

Kugelfischer used to make petrol and diesel pumps and injectors. I once had a very quick Peugeot 504 using them - don't see them commonly though.
Marine engineering is the most basic though - trapped in the 19th century, so likley to use Bosch.

[more]

tohatsu make tohatsu ,mercury engine 3,5-30 hp
tohatsu over 60 hp to 250 hp engine is made by honda, rest part produce tohatsu.

suzuki efi in begining is made from tohatsu lead together project,suzuki seperate tohatsu-mercury today produce this EFI engine 9,9-50 hp normaly today with smaler modification,suzuki hard modification.

tohatsu is beter engine 5 year vs 3 year waranty.

small 1 cy engine 3,5-6 hp from honda,suzuki,yamaha depent year,month,day, location production is from good but mostly ****,heavy **** if use internal fuel tank.
yamaha before couple year have plastic inside engine part. honda 2,5-3,5 if you start new engine you are lucky guy.

my mercury 3,5 hp 3 year old be under see what i know 3 time. 1 time be 20 meter under sea. today working without i disamble becouse is totaly stack. simply wash in fresh water 24 hour, and after this soak in diesel fuel cilindar,and all inside.

for carb cleaning is easy ,dismount carb from outboard put in ultrasonic cleaner et 60C soap water 120 minute, dry return on engine ready for next summer.

suzuki,honda,tohatsu,yamaha,mercury 2 cyl engine over 6 hp made in japan all is good engine for rent is best eletric start and not efi,carb

overal best budget engine is tohatsu DF 9,8 A 5 year warranty.
DFB is efi also good or must have if you need couple nm from your anchor boat.


to many small secret tips and trick in this small engine,but for me this is like shoe. use couple year and by new.
1 day rent and i have new 1 cyl outboard, for 2 cy need 2-3 days rent.
for 4 days i recive new 9,8 and 20 efi, why becouse for day rent now town,marina (new chinese camera instaled if dont pay coming bill on home x3)charge all day +- 20-100€ +-drop anchor outside port load-unload turist and have in 2 week free big outboard.

[CarlF]

It's really simple:

1) Get EFI. Even if you have to go to a heavier/bigger engine. An unrelatible engine is much worse than a heavy engine. Honda 20HP are still carburated. Nothing but trouble if they get near ethanol.

2) Never let ethanol fuel (even 10%) sit in a carburated small outboard or tank.

Suzuki now has a 5 year warranty (at least in the US). I think their EFI models are a little smoother and quieter than the Tohatsu but only a little. At least in Florida and Bahamas service seems better for Suzuki than Tohatsu but these engines are so reliable you aren't likely to need it.

While Yamaha was king of two stroke with the Enduros, their small four strokes aren't as good as the Tohatsu/Mercury and Suzuki - significantly noisier and more vibration. In the Bahamas there's great service for 2 stroke Enduros but they don't generally stock parts for the 4 strokes.

Two strokes burn much more fuel than four strokes - and dump oil in the ocean. I used 2 strokes for 30 years but wouldn't consider buying one new today.

[cottonsail]

Originally Posted by a64pilot

I’m sure there are others, I don’t see the Chinese using Bosch for example, and I’d expect that common rail will bring that monopoly to an end. Ford used a HEUI injector for example, which was everything in the injector, using oil pressure to pump fuel to very high pressure. Common rail has changed things, tremendously, it’s taken a diesels from the mechanical world to the digital one.

https://www.dieselhub.com/tech/heui.html

Common rail is the future, and I’m not so sure Bosch is still a leader in it, they may end up like Kodak.

I’m surprised in a way that mechanical injected engines are still around.

In 2019 I bought a new D2-50F Volvo Penta. It has mechanical injection. I have owned many diesel cars and trucks. Every time I did an oil change the oil was black as mud in 30 seconds of running. This Volvo takes about 10 hours of running before the oil only starts to discolor. That's a very substantial change. The old Westerbeke was 6.2 kts at 1 gal per hour. The Volvo is 6.8 kts at 1 GPH.
A friend of mine has a trucking business. He says electronically controlled diesel truck on the road is the only way to go. On his sailboat one lighting strike andall bets are off.