# 6 HP Tohatsu hard starting



## dabnis (Jul 29, 2007)

We bought a Tohatsu 6HP several months ago and use it about twice a week. It runs perfectly, the only down side is that it takes about 15 pulls to get it started when cold. I follow the instructions to the letter and have tried some variations. End results is 15 pulls. As it has an integral tank there is no bulb to pressurize the system. Anyone have any suggestions?

Paul T


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## Gladrags1 (Apr 9, 2003)

You bought this engine new? Do you use any additives in your fuel to keep it fresh?

I assume that when you are done with your engine and are putting it away for the day, you shut off the fuel and run the engine until the fuel in the carb is exhausted? The hard starting issue might be the result of it takes a while for the fuel to enter the carb. I would try not running the old fuel out of the carb at the end of your period of use, shut off the fuel and see if that helps. 

It might be helpful to use an additive in your fuel to keep it from going bad, phase separating. This keeps you fuel fresh. 

Good luck.


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## lans0012 (Jul 16, 2008)

Sounds like a carb issue. Probably some gunk because of ethanol in the fuel. If I were you and the engine is new I'd take it to the shop you bought it at and have them clean the carb. They may even have some replacement fuel lines that are better for ethanol if they weren't on there already. A new motor has a three year warranty. 

Or just take the carb off yourself. These are very easy to do. Screw driver some sockets. A couple of paper towels, some carb cleaner, and about an hour of your time total. 

Also replace the spark plug for good measure. 

I have the same motor and it likes full throttle and full choke to start up. Back down the throttle when it fires.


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## dabnis (Jul 29, 2007)

Yes, the motor is new. I have tried leaving the gas on between trips, no difference. I use Berryman's B-12 fuel additive. As mentioned it runs perfectly and re-starts fine when warm. I will try the full throttle approach. Thanks fpor the feedback.

Paul T


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## RichH (Jul 10, 2000)

Integral OB, etc. tank systems sometimes need a 'boost' to completely fill the carburetor and to get the carb float to its proper (spec) level - needed to have the correct air/fuel ratio.

As a trial, open the 'gas cap', seal the tank opening with your mouth and BLOW (5 - 10 seconds) into the tank to pressurize the fuel ... will fill the carb bowl until the float valve closes. If this corrects the hard-start, then either get or retrofit an external tank with 'squeeze bulb' or install a mini-squeeze bulb (Walbro, etc.) between the tank and the carb.

On small HP OBs BE SURE to only use FRESH (less than 30-45 day old) gasoline, dont depend on 'stabilizers but still use them, and BE SURE to always run the engine DRY of fuel when shutting down. For storage of more than a month or two, always open the carb drain plug to BE SURE that no gasoline is remaining in the carb bowl ... you can squirt in Isopropyl alcohol (IPA) to help keep the developed 'varnish and gums' to a minimum.

The correct starting fuel/air ratio for most Tohatsu (6hp) OB will be with the throttle set EXACTLY with the indicator between the 'rabbit' and the 'turtle' and the choke pulled - 'all the way out'. If you need to start on either side of that 'index' then the carb usually need cleaning and readjustment.

The usage of 'ethanol free' marine fuels (not available everywhere) will greatly help with 'hard-starting' and degraded performance. Go to ValvTect website to locate 'ethanol free marine fuels'. Locator: ValvTect - Certified Marinas

Good luck, but expect such nonsense to get much worse with increasing ethanol content in gasoline.


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## dabnis (Jul 29, 2007)

RichH said:


> Integral OB, etc. tank systems sometimes need a 'boost' to completely fill the carburetor and to get the carb float to its proper (spec) level - needed to have the correct air/fuel ratio.
> 
> As a trial, open the 'gas cap', seal the tank opening with your mouth and BLOW (5 - 10 seconds) into the tank to pressurize the fuel ... will fill the carb bowl until the float valve closes. If this corrects the hard-start, then either get or retrofit an external tank with 'squeeze bulb' or install a mini-squeeze bulb (Walbro, etc.) between the tank and the carb.
> 
> ...


Rich,

Very interesting, I will try the pressure test and throttle setting tomorrow. Other than the hard cold starting it runs perfectly at all speeds and loads so I am cautious about adjusting the low speed mixture.

Thanks for the feedback, Paul T


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## dabnis (Jul 29, 2007)

dabnis said:


> Rich,
> 
> Very interesting, I will try the pressure test and throttle setting tomorrow. Other than the hard cold starting it runs perfectly at all speeds and loads so I am cautious about adjusting the low speed mixture.
> 
> Thanks for the feedback, Paul T


Rich,

Half throttle worked well, about 6 pulls instead of 15, didn't need the pressure test. It caught me by surprise, 5 pulls, not a wimper, 6th pull must have been close to the rev limiter by the time my brain engaged and I turned it down, next time I will be ready for it. Thanks for the suggestion.

Paul T


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## RichH (Jul 10, 2000)

Good to hear! Suggest you 'run hell' of it with fresh gas and new stabilizer, etc. so those teeny problem passages in the carb begin to 'clean out'. ;-)


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## ebs001 (May 8, 2006)

I have a Tohatsu 9.8 four stroke and I used to have a really tough time starting it when the engine was cold. I took it in for a tune up and I have no idea what they did but I have not had a problem since. Before I go cruising next winter I will take the motor in for servicing again. At a cost of $100, for me it's money well spent.


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## TohatsuGuru (Oct 3, 2007)

If it is not starting on the first pull there is a problem. That problem can be anything from lack of knowledge of how to correctly start the engine, fuel system issues or a mechanical malfunction. Your local dealer is your best resource as they can physically see what you and the engine are doing...


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## dabnis (Jul 29, 2007)

TohatsuGuru said:


> If it is not starting on the first pull there is a problem. That problem can be anything from lack of knowledge of how to correctly start the engine, fuel system issues or a mechanical malfunction. Your local dealer is your best resource as they can physically see what you and the engine are doing...


Guru & Rich,

Thanks for your input. As mentioned earlier, it runs perfectly from just barely ticking over to full throttle for a long time. We are at 6,000 feet but I would think that might present a slightly rich condition? I think I will give it a little extra Berryman's B-12 fuel additive and see what happens. Nearest dealer is a 100 mile trip, I can live with a few extra pulls. Thanks again for your help.

Paul T


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## TohatsuGuru (Oct 3, 2007)

You have identified a problem, if not the problem. Your engine is drowning in fuel at that altitude with the stock jets. See your local Nissan, Tohatsu, Mercury or Evinrude dealer and get the correct jets. You have a 20 to 15% loss in power and the engine would run tend to be hard to start...


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## colinflteng (Aug 15, 2010)

I change my spark plug proper gap after engine was hard to start and would run for up to 2 minutes starts one to two pulls 
Cheers Keep it simple


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## dabnis (Jul 29, 2007)

colinflteng said:


> I change my spark plug proper gap after engine was hard to start and would run for up to 2 minutes starts one to two pulls
> Cheers Keep it simple


"Keep it simple", how true, how true. The manual calls for .031 to.035. Mine measured a loose .035. I re-set it to a snug .031and will try it in a couple of days. Brand new motor just out of the box, I assumed everything was right on spec. Should have checked right away. Thanks for the tip.

Paul T


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## RichH (Jul 10, 2000)

TohatsuGuru said:


> You have identified a problem, if not the problem. Your engine is drowning in fuel at that altitude with the stock jets. See your local Nissan, Tohatsu, Mercury or Evinrude dealer and get the correct jets. You have a 20 to 15% loss in power and the engine would run tend to be hard to start...


Definitely high altitude will change the air/fuel ratio. Definitely consult with a dealer/mechanic who is knowledgeable in operating these OBs at high altitude to install the correct jets (or redrill them) for this high altitude operation. If you cant find a local Tohatsu mechanic, You might also want to visit a 'carburetor' specialty shop in this specific area shop that follows/caters to the 'hot rodders'.


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## dabnis (Jul 29, 2007)

dabnis said:


> "Keep it simple", how true, how true. The manual calls for .031 to.035. Mine measured a loose .035. I re-set it to a snug .031and will try it in a couple of days. Brand new motor just out of the box, I assumed everything was right on spec. Should have checked right away. Thanks for the tip.
> 
> Paul T


Curiosity got the better of me and I just ran it in a barrel. 2 pulls, fired right up and ticked over perfectly. Never assume anything, I really feel dumb for not checking the plug gap from the very beginning. We have about 30 trips on it, so 13 extra pulls per trip comes out to be about 400 extra pulls I didn't have to do if iI had checked it right away. Guru & Rich, thanks for the altitude tips but as it runs perfectly at 6,000 feet and we go to some lakes that are close to sea level I will just leave it alone, especially now that it starts in 2 pulls. Colin, thanks for pointing out something I should have known, it just went right over my head. Never assume anything.

Paul T


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## colinflteng (Aug 15, 2010)

Pass it on: old retired fisherman suggested the spark plug after I had done all the fuel fixes I going to change plug very year 
Good sailing 
Cheers Colin


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## dabnis (Jul 29, 2007)

colinflteng said:


> Pass it on: old retired fisherman suggested the spark plug after I had done all the fuel fixes I going to change plug very year
> Good sailing
> Cheers Colin


I had a lot of 2 strokes over the years and was always careful to keep fresh properly gapped plugs in them. 4 strokes seemed to be more tolerant so I didn't change or check them all that much. Your tip really proved me wrong.
One can always learn from others.

Thanks, Paul T


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## dabnis (Jul 29, 2007)

dabnis said:


> Curiosity got the better of me and I just ran it in a barrel. 2 pulls, fired right up and ticked over perfectly. Never assume anything, I really feel dumb for not checking the plug gap from the very beginning. We have about 30 trips on it, so 13 extra pulls per trip comes out to be about 400 extra pulls I didn't have to do if iI had checked it right away. Guru & Rich, thanks for the altitude tips but as it runs perfectly at 6,000 feet and we go to some lakes that are close to sea level I will just leave it alone, especially now that it starts in 2 pulls. Colin, thanks for pointing out something I should have known, it just went right over my head. Never assume anything.
> 
> Paul T


An update. After writing the above the motor went back to 10 to 15 pulls, seems like I fooled myself the first time.

I bought the external tank and now after squeezing the bulb until it is firm, it takes 1 to 2 pulls. The motor runs perfectly with the stock jetting even at 6,000 feet elevation. Apparently, the fuel pump just took that many pulls when using the integral tank. Exercise is OK, I guess, but this is MUCH easier.

Paul T


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## Seaduction (Oct 24, 2011)

dabnis said:


> An update. After writing the above the motor went back to 10 to 15 pulls, seems like I fooled myself the first time.
> 
> I bought the external tank and now after squeezing the bulb until it is firm, it takes 1 to 2 pulls. The motor runs perfectly with the stock jetting even at 6,000 feet elevation. Apparently, the fuel pump just took that many pulls when using the integral tank. Exercise is OK, I guess, but this is MUCH easier.
> 
> Paul T


I missed the older posts, but I have the 6hp Tohatsu with a separate 3 gallon tank and primer bulb. It starts on 1 or 2 pulls usually. I think the lack of a primer bulb was your nemesis.


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## dabnis (Jul 29, 2007)

Seaduction said:


> I missed the older posts, but I have the 6hp Tohatsu with a separate 3 gallon tank and primer bulb. It starts on 1 or 2 pulls usually. I think the lack of a primer bulb was your nemesis.


Agree, as we only burn about a pint of fuel per trip I was hesitant to get the external tank which was a mistake. 15 pulls every morning was getting to be a bit much. In an earlier post Rich H suggested blowing into the tank to pressurize the carb. I thought about that but decided to just get the external tank. The motor runs perfectly, like all the other Japanese made products I have had.Life is good

Paul T


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