My 2008 tohatsu new last season has maybe 10 hours on it. I use it mainly to get off my mooring. A week ago I noticed the motor was running uneven and surging at idle I called the dealer and after failing to adjust the carb on the phone he told me to bring it in. The carburetor had to be totally cleaned. Not covered under the warranty. I asked him how an engine with maybe 10 hours on it would have a gummed up carburetor. He didnt know The only thing he said was old gas. I use 93 octane gas, put a capful of startron in the tank when filling and when the gas is 30 days old I dump it in my car and replace it with fresh. I never run the engine very fast and always run it out of gas when Im through with it for the day Anyone have any ideas about what causd this problem.
outboard problems 2008 8hp tohatsu
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On my 4hp Tohatsu there is a rubber Plug in the motor cover that allows you to reach the drain plug on the carb bowl .(it does NOT have to come all the way out to drain )
Running it OUT of fuel leaves a lot of fuel in the bowl and IMHP your better to leave it FULL or DRAIN it
I place a paper towel under it to collect the fuel
It sucks BUT all NEW small outboards suffer the same problem as the fuel sucks and the EPA requriments force them to use really small jets that clog very easy compared to old motors
Running it OUT of fuel leaves a lot of fuel in the bowl and IMHP your better to leave it FULL or DRAIN it
I place a paper towel under it to collect the fuel
It sucks BUT all NEW small outboards suffer the same problem as the fuel sucks and the EPA requriments force them to use really small jets that clog very easy compared to old motors
I have found that my 2006 outboard needs new spark plugs at the start of each season, or it will run rough.
From all the available information, I too thought it was a carb/fuel problem. I rebuilt the carb and noted two things: 1 It was squeaky clean and all parts looked brand new. The rebuild was unnecessary. 2. The design is very simple and elegant with no internal adjustments possible. It should last a long time before a rebuild is required.
I did every other thing possible to the fuel supply. Fresh fuel, new filters, added water separation filters.
No change, still ran rough until I replaced the plugs. The old plugs always look serviceable, so all I ever did was check the gap and re-install them.
It's annoying because we have all this yard care equipment that starts and runs well regardless of the condition of the gas. Yet at every turn the service people state the problem with the outboard is old fuel. On a 4 stroke no less. The lawn mower and the outboard start about the same number of times and run about the same hours. Such is life !
From all the available information, I too thought it was a carb/fuel problem. I rebuilt the carb and noted two things: 1 It was squeaky clean and all parts looked brand new. The rebuild was unnecessary. 2. The design is very simple and elegant with no internal adjustments possible. It should last a long time before a rebuild is required.
I did every other thing possible to the fuel supply. Fresh fuel, new filters, added water separation filters.
No change, still ran rough until I replaced the plugs. The old plugs always look serviceable, so all I ever did was check the gap and re-install them.
It's annoying because we have all this yard care equipment that starts and runs well regardless of the condition of the gas. Yet at every turn the service people state the problem with the outboard is old fuel. On a 4 stroke no less. The lawn mower and the outboard start about the same number of times and run about the same hours. Such is life !
The lawnmower does NOT have to meet the 2008 CARB 3 star rating YET
And if they had there way your lawnmower would allready have a CAT on it
And if they had there way your lawnmower would allready have a CAT on it
I would not trust my well being on the water to a lawnmower so cannot see a fair comparison. I second what Tommays says, drain it all the way or leave it full. A small amount of fuel left on the bowl will evaporate and dry quicker than fuel on a full bowl. Old fuel/new fuel does not make a difference when it dries and gums it will clog a carburator. As a rule of thumb I will leave the carburator full if the engine will not be in use for up to two months but if it will be laid up longer I will drain all the gas.
I had this EXACT same problem with our new 2009 9.8 Tohatsu in June. We had it on maybe three weeks when all of a sudden it just petered out while idling - same thing, only about 10 hours on it. We took it into a service rep and he also blamed bad gas. I didn't question it as there had been reports of bad gas in the area about that time. He completely reworked the carburator and replaced all the fuel lines and we replaced the gas with fresh gas all this for about $215. That fixed the problem but not for long. After a few days we had the same problem again! Turns out it very well could have been bad gas initially (he drained the carb in front of me and it LOOKED bad), but the second time was due to the hose fitting that plugs the fuel line into the motor. If you look in the female fitting thing that fits onto the male motor fitting you will see a round ball bearing type of thing. Fuel is released when the ball is pushed in by the pin. (Sorry about my non technical lingo). When the pin on the motor side hits the ball in the hose it pivots to the side and it does not release enought gas to keep the motor running. When we finally determined that that was the problem he cut off the factory supplied fitting and put on a different one that has a flat surface in it. Problem solved and no charge for the new fitting!. As a precaution I also bought a fuel filter that is mounted between the gas can and the motor, plus we use Sta-Bil and an enzyme treatment. I hope this helps.
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What Marcia said. Additionally check that the fuel hose seals tight at engine. Sometimes a side strain on the fuel hose will make it suck air and run rough. This happened to two different new Tohatsu motors I have had. After I figured this out, the motors ran perfect. Good luck.
If your Tohatsu is a 2-stroke you have answered your own question. You never run it fast. BAD IDEA. Small engines NEED to be run. Even if it is a 4-stroke. Low speed, light load causes carbon build-up on the white porcelain insulator at the center of the spark plug. At some point the spark, instead of jumping the gap, bleeds down the carbon trail on the porcelain which is no longer an insulator. Ever hear the term "Blow it out"? This is exactly what it refers to. Take that engine out and rampp it up to full speed and load over a period of time, then run it hard for 15 minutes or so, then see how it idles. The heat of combustion in an engine happily at work cleans off the spark plug. Or spring for new plugs. And don't foul them by running at low load.
Second item: There is no reason to run High test (93 octane) gas in a simple, normal compression engine. Anyone who says there is has no idea what he is talking about. High test's reason for being is that it is formulated so that it is HARDER to light off. It is intended for use in HIGH COMPRESSION, high performance engines. High compression causes high heat on its own. Pump up a tire with an old, metal bicycle pump. feel the base. HOT??? A high compression engine can compress to the point it will light off the fuel charge before the spark. "PREIGNITION". Preignition burns/hammers holes in the tops of pistons. If you're above about 9:1 by all means use High Test. If not, save your monbey and use regular, the correct choice. I have SEEN all of this personally.
And oh yeah, keep fresh gas in it.
Sam
Second item: There is no reason to run High test (93 octane) gas in a simple, normal compression engine. Anyone who says there is has no idea what he is talking about. High test's reason for being is that it is formulated so that it is HARDER to light off. It is intended for use in HIGH COMPRESSION, high performance engines. High compression causes high heat on its own. Pump up a tire with an old, metal bicycle pump. feel the base. HOT??? A high compression engine can compress to the point it will light off the fuel charge before the spark. "PREIGNITION". Preignition burns/hammers holes in the tops of pistons. If you're above about 9:1 by all means use High Test. If not, save your monbey and use regular, the correct choice. I have SEEN all of this personally.
And oh yeah, keep fresh gas in it.
Sam
Not that it can't be, but if they just want your money they say CARB problem, Carb adjustments and cleanings are not covered under warranty, as you found out. Most of the time it is something else, on a new or newly serviced motor. Bad fuel makes a motor run bad but don't usually require the carb to be cleaned. Replace with good fuel and drain the carb, should be enough. Dealer took your money.
Everbody does their own thing so here is mine.. I have a 9.5 hp, 8 hp, 3.5 hp, and a 2.5hp, all 2 stroke. they all get used from October thru Febuary then stored till next October. When done for the day I ALWAYS run the carb out of fuel, but never drain the Float bowl. Never have a problem. I don't use fuel additives just the 2 stroke oil.
Big hint on the fuel tank. DON'T leave the vent open when not in use. Keep the tank covered from the sun when not used but keep the vent closed. If Open, when the tank expandes and contracts with the Tempeture changes it will pull moist air in and out and contaminate your fuel
Brian
Everbody does their own thing so here is mine.. I have a 9.5 hp, 8 hp, 3.5 hp, and a 2.5hp, all 2 stroke. they all get used from October thru Febuary then stored till next October. When done for the day I ALWAYS run the carb out of fuel, but never drain the Float bowl. Never have a problem. I don't use fuel additives just the 2 stroke oil.
Big hint on the fuel tank. DON'T leave the vent open when not in use. Keep the tank covered from the sun when not used but keep the vent closed. If Open, when the tank expandes and contracts with the Tempeture changes it will pull moist air in and out and contaminate your fuel
Brian
SamLust has it
I've a 2004 8hp Tohatsu 4-stroke (I don't think you could buy a two stroke 8 in 2008). I've also had the same problem after lots of putt-putt trips in and out of the marina. You have to RUN the thing and with proper maintenance, you should be fine.
I've a 2004 8hp Tohatsu 4-stroke (I don't think you could buy a two stroke 8 in 2008). I've also had the same problem after lots of putt-putt trips in and out of the marina. You have to RUN the thing and with proper maintenance, you should be fine.
Hello
Bad gas happens in a very short time! To see this for yourself just half fill a clean paint can cap with new gas and set it outside for a day. All the gas will dry out. This is what the carburator , gas tank , and every thing else sees. Gasoline doesn't last long exposed to air. Always close any closeable vent when periods of non use are seen. 2 strokes aren't as bad because the mixed oil tends to help.
While your at it replace the fuel hose and carry a spare.
The engine's fuel system has many very small passage ways that can easily plug up from dry gas.
So always empty the fuel system by running out of gas and use the choke at the end to get every drop out. Stay dry and keep your wallet closed.
Bad gas happens in a very short time! To see this for yourself just half fill a clean paint can cap with new gas and set it outside for a day. All the gas will dry out. This is what the carburator , gas tank , and every thing else sees. Gasoline doesn't last long exposed to air. Always close any closeable vent when periods of non use are seen. 2 strokes aren't as bad because the mixed oil tends to help.
While your at it replace the fuel hose and carry a spare.
The engine's fuel system has many very small passage ways that can easily plug up from dry gas.
So always empty the fuel system by running out of gas and use the choke at the end to get every drop out. Stay dry and keep your wallet closed.
I've just joined up from Australia and hope someone is better than me at diagnosing outboards. My Tohatsu 8 took a bath during a storm when dinghy sunk. I needed to go someplace soon after recovering it, so washed it down with fresh water and filled bores with outboard oil (the only thing I had handy) and left. I've since cleaned it out completely with WD40 and petrol, took the carb apart (it was gunky) cleaned it very carefully throughout, blew out all fuel channels etc. I can get it to start when I leave some petrol in the cylinders, but it quickly dies. Kept thinking the plugs (I put in new) were fouling, kept running petrol through, cleaning plugs etc, but still it just starts, runs a moment and dies. Now I think it's not getting fuel, but another carb dismantle shows all clean and clear. Starts right up with a spoon of fuel in the bores, but soon dies. Any suggestions?
Replace the jets. They were sitting with water in them for several days and have probably started to corrode.
Actually, there's a great reason for using the highest grade of gas, at least in our neck of the woods - it has less or no ethanol. In fact, around here Shell states that there's 0% ethanol in their "Gold" gas.
Ethanol likes water and will grab it out of the air, so the longer you have a tankful, the greater the likelihood that the gas will have water in it.
Caveat: Our engine is a 1983 Suzuki 5 HP 2-stroke. It nearly always starts first pull, will run smooth for hours and i love it to bits.
I don't buy the "bad Gas" excuse!!! I use the gas for my lawnboy 2 cycle( read that as made by the outboard motor people) mower from season to season with no trouble. I clean the air filter once each year and shove it into the shed when I am finished. I can't recall the last time I changed the spark plug. It always starts on the first or second pull and has for 15 years.
Well... I've seen for myself how last-year's gas looks/smells compared to a fresh fill, and I've read elsewhere that most outboard mechanics point to bad gas as the #1 cause of poor operation and not starting. I can also attest that from participating in a few group outings, the guys with the most problems were the ones who just pulled out the motor and last year's gas out of the toolshed, and threw it on the boat. These guys often had fouled plugs, stuck needles etc.
Some users store their outboards without doing much in the way of maintenance, and they have few problems. The key seems to be to store the motor upright - which keeps gas in the right places, i guess. Many of us have to store our motors laid down, so of course the gas is going to run to different spots.
Re your lawnmower - your gas tank is alot smaller than the average boat tank, so you have alot less gass sitting there going 'bad'. And if you top up in the spring with new gas, that helps as well, right?
Our outboard is potentially a safety device when we're out on the Great Lakes, so as much as I hate having to get rid of last year's gas, I consider it a justified expense. I use premium (no ethanol) good 2-stroke oil, and fuel stabilizer, and our outboard has been very dependable.
The 'problem' is the Ethanol used to thermodynamically dilute gasoline in the USA. Upon short term storage the water in the ethanol (ethanol production INCLUDES water) separates into a distinct 2 part 'liquid - liquid' phase (which doesnt gravimetrically settle out to the bottom of the tank). Such 'phase separation' enhances the formation of gums/varnish/shellacs - especially in the very fine orfices and passages in small carburetors. Plus, most of these small carburetors have their 'fuel/air' ratio chiefly controlled by an 'emulsion tube' (essentially causes a 'foam' of fuel/air in a small tube that feeds the venturi section) ---- the phase separation changes the 'surface tension' of the 'foam', thus the 'foam' bubbles are not the correct size, .... and thus you lose control of the air/fuel ratio (simple speak: - runs like sh*t). In automobiles, etc., the high pressure fuel pumps and fuel injector systems will 'emulsify' the different liquid phases back into one single phase (with single surface tension). Older autos still with carburetors are having the exact same wholly unnecessary thuggery of 'eco-trauma' as those of us with small/carbureted outboards (or lawn mowers, weed-whackers, chain-saws, and other small engines.
When I cannot get **RECREATIONAL (NonEthanol adulterated, 90 Octane) Gasoline** - sold in many 'southern' states - I use one of the newer 'Startron' additives for 'ethanolated fuel' to prolong the 'shelf/storage life of the fuel .... OR .... if the gasoline (already with added stabilizer) starts to go-over-to-the-darkside and form deposits in my Tohatsu Carb (6Hp), I add 'standard carburetor cleaner' to the gasoline and run the engine for several hours at WOT clean the carb - this usually cleans the deposits without carb disassembly. Many of the 'recreational gasoline' suppliers (ValveTech, etc.) probably already have such 'cleaning compounds' added to their fuel - 1-2 gallons of ValveTech 'recreational' gasoline usually 'clears' my Tohatsu carb.
I recommend that anyone using the ethanolataed fuels in their outboards: 1. use only FRESH fuel. 2. Add a stabilizer that is especially formulated for "ETHANOL laden gasoline", 3. ALWAYS run the carburetor DRY before even short term storage.
I suggest that Al Gore and the other thermodynamic idiots be *forced* to start using ethanolated fuels in their private aircraft, limousines, etc.
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