Difficulty with New Tohatsu

[ppine]

I have been running outboards for 60 years, mostly 2 strokes and all used. I have had a 1963 Mercury 6 Twin that was a one pull motor. I had a 1975 Johnson 6 on a sailboat that was one pull. When I was a kid we had a 1929 Johnson 1 1/2 horse that still runs and sits in my garage.

I bought a 6 hp Tohatsu for my drift boat to fish on lakes. It is a 4 stroke engine, long shaft and a 2021 model my first new outboard. I understand that the newer engine are detuned and run lean. I live at 5,000 feet but this engine is supposed to only need hi alt jets above 8,200 feet.

The outboard is new and a little stiff but very hard to start. This is especially true if conks before fully warmed up.
I would like to hear any suggestions that people have for starting new 4 stroke engines. This is very frustrating to say the least.
The old engines worth $200 ran like a dream, now that I have spent the money I have blisters on my hands from pulling the starter rope.
Help.

 

[CedarRiverScooter]

Is the choke closing al the way?

I have found on small engines that if you close choke, pull it through a couple times slowly (gets gas in cyl) then pull it fast, it starts right up. Maybe good to open choke 1/2 way on 3rd pull so you don't flood it.

 

[RaisedByWolves]

4stroke Dirt bike trick may apply.

Pul it over slowly until just past TDC on the compression stroke, let the rope retract, then yank.

This lets the flywheel do a lot of the work.

 

[turbotodd]

many of the tohatsu smaller motors have either a nonexistent or poor compression release. Second you have a single cylinder 4 stroke. The combination is going to be a little on the rough side to start manually. The 4 stroke dirtbike trick is about all you can really do. This assumes that the engine valve clearance is within spec, or maybe on the tighter end of spec. I mention this because as the clearance opens up, looser valve clearance tends to cause more engine compression.

 

[MrGiggles]

4stroke Dirt bike trick may apply.

Pul it over slowly until just past TDC on the compression stroke, let the rope retract, then yank.

This lets the flywheel do a lot of the work.

This. Some technique may help quite a bit. Those 4 strokes have a pretty high compression ratio.

Works on big ATVs if you ever kill your battery too. Those big 600-700 singles are hard to pull, roll it over the bump slowly, then give it a yank, otherwise they'll just about rip the handle out of your hands.

Is it hard to pull or just hard to start, as in it takes a lot of pulls? I would check the choke/throttle adjustments and make sure that they are correct, and change the spark plug as well, may be a little fouled from assembly lube.

Being new may be part of it as well, should get better once it's fully broken in. Try not to idle and run it pretty hard for the first few hours.

 

[ppine]

Thanks for the replies.
The engine is getting plenty of fuel.
The spark plug is covered in black soot and wet.
Maybe less choke will work.

 

[jethro]

I have that same exact motor as my kicker, just 14 years older and with a Mercury sticker on the cowl and all the things you say are correct. If you don't get it idling on that first time it kicks over, it's a nightmare to get going after that. I wish I had more encouraging things to say, but I hate the damn thing. All it's taught me is never to buy a manual start, carbureted 4 stroke motor for a kicker again. And the single cyl. is a mistake also- at least for me. It is a chunky running motor, shakes my whole 3500lb, 21' trolling boat like crazy. For trolling purposes a twin is ESSENTIAL for anything I get in the future- what a mistake. My only advice is make sure you set yourself up as good as possible to get it running on that first or second pull when it first fires. Pump the ball firm, pull the choke and throttle it up a little so when you push the choke back it doesn't stall. Make sure your choke is doing the right thing, it should not only block the throttle body but also give it 1/4 throttle. If the choke cable isn't set perfectly it won't throttle up correctly. It's also sensitive to ANY air leaks in the fuel line. The best thing I did was install Tygon clear fuel lines so I can see if there are air bubbles in the fuel line. If there are any present at all the tiny, tiny fuel pump just won't push fuel.

Wish I could be more encouraging, but I've been looking to replace this motor for years with a fuel injected, twin cyl. kicker with a little more charging capability for almost as long as I've owned it. If I can say one good thing, it's pushed my boat around at 1.8-2.2 mph for hundreds upon hundreds of hours- once it's running it stays running quite well.

 

[MrGiggles]

I have that same exact motor as my kicker, just 14 years older and with a Mercury sticker on the cowl and all the things you say are correct. If you don't get it idling on that first time it kicks over, it's a nightmare to get going after that. I wish I had more encouraging things to say, but I hate the damn thing. All it's taught me is never to buy a manual start, carbureted 4 stroke motor for a kicker again. And the single cyl. is a mistake also- at least for me. It is a chunky running motor, shakes my whole 3500lb, 21' trolling boat like crazy. For trolling purposes a twin is ESSENTIAL for anything I get in the future- what a mistake. My only advice is make sure you set yourself up as good as possible to get it running on that first or second pull when it first fires. Pump the ball firm, pull the choke and throttle it up a little so when you push the choke back it doesn't stall. Make sure your choke is doing the right thing, it should not only block the throttle body but also give it 1/4 throttle. If the choke cable isn't set perfectly it won't throttle up correctly. It's also sensitive to ANY air leaks in the fuel line. The best thing I did was install Tygon clear fuel lines so I can see if there are air bubbles in the fuel line. If there are any present at all the tiny, tiny fuel pump just won't push fuel.

Wish I could be more encouraging, but I've been looking to replace this motor for years with a fuel injected, twin cyl. kicker with a little more charging capability for almost as long as I've owned it. If I can say one good thing, it's pushed my boat around at 1.8-2.2 mph for hundreds upon hundreds of hours- once it's running it stays running quite well.

Ever check the valves?

I've seen some ATV engines and stuff that were very hard starting, the valves were tight and hanging open, once they warmed up a little the seats would swell just enough to seal and they would run normally.

 

[jethro]

Ever check the valves?

I've seen some ATV engines and stuff that were very hard starting, the valves were tight and hanging open, once they warmed up a little the seats would swell just enough to seal and they would run normally.

I have not checked the valves but that's a good idea. It does start better/easier after it's fully warmed up, so might make sense.

 

[ppine]

After some trial and error the problem is mostly solved. I start the motor cold with the choke only about half way out. I start it warm with no choke. The motor is now a 2 pull motor. Because it is a one cylinder it does have more vibration than the old 2 cylinder engines. One thing that helps is to close the latches on the seats in my boat so they don't vibrate.

The 6 hp has plenty of power and my drift boat moves right along at 1/3 to 1/2 throttle.
Thanks for the replies everyone.

 

[Sinkingfast]

...and what did ya do to mostly fix it?

 

[ppine]

Half choke for a cold start.