2003 Tohatsu 9.8B 2 Stroke ran good now wont start

[Bosunsmate]

Also I did not run the hose for this so I think water in the gas would be tough.

Not so, if your exhaust gasket went while you were out boating there could be water emulsified oil through your crankcase so when you try and start it the fuel just gets wet when passing through the crankcase again.
Your initial plug condition sounds like fuel emulisified with water

 

[panamakid]

What is the repair for water in the crank case? Do I need to pull the powerhead and crack the case and look for bad seals?

 

[panamakid]

You got 140 PSI with tester, after how many pulls ?
Happy Boating

With 4 pulls i get 130 PSI.

I got 140 PSI with lub oil squirted in spark plug holes and using cordless drill on flywheel. turned like 5x the speed a starter motor would.

 

[Bosunsmate]

What is the repair for water in the crank case? Do I need to pull the powerhead and crack the case and look for bad seals?

I dont have a schematic for tohatsu is it the same as a merc?
If the exhaust water housing is not sealed and has a gasket with plates then i would remove those as they would be more likely your cause as the head gasket compression sounds fine.
The exhaust gaskets are way cheaper too.
But i would not do that until i confirmed that the wetness was water emulisified fuel
You would then probably need to remove the carbs and intake cover and spray carb cleaner all through it and tilt it so it drains out. Well thats what i had to do with mine plus cleaning the idling/scavneging hoses, but that was on a 90hp so yours probable wont have them

 

[panamakid]

here is the schematic. So I should remove the exhaust cover and inspect the gasket. If broken replace.

Then flush out cranks case with carb cleaner and drain out?

 

[Bosunsmate]

here is the schematic. So I should remove the exhaust cover and inspect the gasket. If broken replace.

Then flush out cranks case with carb cleaner and drain out?

What you need to do is confirm that you are getting water still on the plugs by doing that wetness and light test definitively.
When you remove the exhaust cover you will destroy the gaskets so its very hard to see if that was the problem.
But yes you would then need to remove that front cover on the crankcase and flush it out.

You can also remove pipe 2 and 3 as shown in the diagram and check them and their valve and hoses as if water has got into the motor those hoses will often get that gunk you describe in it too.
You should do that first as that will take thirty seconds to check

 

[Bosunsmate]

The nipples in those lines will clog up from the emulsifiation and will seem hard to blow through, or suck, one way or the other, they have check valves so you check by blowing or sucking.

 

[panamakid]

Thank you everyone for the great advise. I will retry to lighting the spark plugs on fire.



I do feel the engine is acting as if the gas is watery with the half hearted pops and farts( it is fresh gas and free of water while in the can/hose).


Assuming it is only the exhaust gaskets, in theory I could flush the crank case of any water with carb cleaner, reassemble, and start it (without the hose for a few seconds) to test the theory. I realize this is hard on the impeller

If that works then I could start looking in to exhaust gaskets, and cooling hoses, ect..


Or B: I could take it to the Dealer$$

Or C: Sell as is on craigslist.

I would hate to break off a old bolt in the block. I do not have access to torches, taps/dies and machine shop type equipment.
What would you guys do?

 

[Bosunsmate]

Drop the LU, then you dont need to bother about the impellor.
Pull out those hoses and spray as much carb cleaner through it as you can
Retry

 

[Sea Rider]

Some issues ;

How can you assume there's water inside crankcase if ever was there with all the pulls you have given the engine. Have not changed a single exhaust gasket ever mostly because I torque the whole engine gaskets from time to time. Happen to have in use engines with more than 1.5K worked hours still with factory delivered exhaust gaskets.

The only possibly way to have an exhaust gasket failure or one giving water entering issues is if engine was severely used and never have been torqued from new as the owner's manual states it's a must do, that applies to all outboards brands. An engine with lower unit not submerged on water, should start inmediately, not with a blown gasket if this is the case.

You can have already a blown head gasket. If gasket was blown while engine was running at speed due to inside corrotion, being old, dried and hardened, that engine will not restart not even calling the witch doctor. Head gaskets which deals with extreme heat and worst if engine is used on salted water will not last forever...



I'll bet it's a CD/IC or a head gasket related issue. Take it to dealer and have a service quote, can accept it or reject it. At least will know for sure which part was the culprit for engine not starting after it was running good.

Happy Boating

 

[panamakid]

Thanks everyone for your help.

 

[panamakid]

I assumed water was in the engine because the gas on the plugs was not lighting on fire when I put a match to it.

I have decided to take it to the dealer for a diagnostic. Dealer said $75 for a repair estimate/trouble shooting.

At least them I will know if I should sink money into a 11 year old kicker or sell as is and look for one in better shape.

I will post updates.

- Also would cylinder compression be strong if head gasket is bad?

I assumed because of my compression numbers that the gasket was ok.

 

[Sea Rider]

Some issues :

Compression is measured with warm engine, in your case engine is cold dead, if you squirt oil into cylinders wlll increase PSI, is not the same pulling rope by hand than having a driller move the engine with lots of turns as opposed doing it manually. How can you possibly have 140 PSI when service manual calls for 57 PSI achieved through at least 4 compression strokes.

You can only light a plug if engine is severely fuel overfloaded which is not your case, when starting there's a minuscular amount of air/fuel inside cylinders, enough to turn engine on. So lighting a plug is not a concluding test. If water enters combustion chamber will oxide plug tip.

Was that engine used severely through those 11 years, probably impossible to tell, you could even have a low compression issue associated to a blown head gasket which lets water inside combustion chamber and shuts engine down as when you were left stranded.

It's not a matter on how old an engine is, it's a matter on how well the engine was serviced and looked after during its entire life. 75 bucks will be the best invested money ever, keep that portable engine it's one of a kind, outperforms any 8 HP any time, any day.

Happy Boating

 

[panamakid]

I have done the compression test many times. Dry with one pull they goes to 90 PSI, by the 3-4th pull I am at 130 PSI.

I believe the manual is a misprint, 57 PSI for a gas engine is pretty low.

When I say I squirt oil in the cylinders, I am talking a small amount of WD40. I know it is not the best for this but figured it would allow the rings to make a good seal, and not rub dry on cylinder.

I agree $75 for a quote is fair. I just hope it is not a $400 repair for a little old 2 stroke.

 

[panamakid]

Engine was dropped at dealer for a diagnostic, Will report when they call with issue.

 

[Sea Rider]

Engine was dropped at dealer for a diagnostic, Will report when they call with issue.

If engine was running good, internal parts rotates freely, have spark in both cylinders, good compression, the repair bill should not be costly, parts are relatively cheap, don't know about dealer's hand labor costs which can increase final bill astronomically if having out of this world prices, let's hope not.

Happy Boating

 

[Bosunsmate]

If engine was running good, internal parts rotates freely, have spark in both cylinders, good compression, the repair bill should not be costly, parts are relatively cheap, don't know about dealer's hand labor costs which can increase final bill astronomically if having out of this world prices, let's hope not.

Happy Boating

Yes it should really only cost you $75 plus parts as once you know whats wrong us here should be able to direct you how to repair

 

[panamakid]

I took the Engine to the local Tohatsu dealer.

They told me that "the compression was only 60 PSI in each cylinder and that it was not worth rebuilding".


I told the tech that this was hard to believe as I had just bought a new compression gage and had done this test many times.

We walk into the shop, I hook up the gage and pull the cord 1 time it goes to 110 PSI, 2nd pull 130PSI....

I turn to the tech and ask what he did when he tested it, he said the same thing. We did it again and we both get 130 psi by the 2nd or 3rd pull (SAME with both cylinders)

He then says well some times you can still need new rings/pistons even if compression is good.


I then asked if he checked the CDI with his equipment, he said "well you have spark so no".

I asked well what did you do to trouble shoot it? He said tried to start it, and did compression test (incorrectly)...


The Tech offered to crack the block and look but the shop labor rate is $100 per hour plus parts.


The owner was really nice and waived the diagnostic fee. I get the feeling it is hard for a business to make money on a 11 year old kicker. They were busy and the shop was full of bigger, newer engines.


On the way home I stopped at the local Yamaha marine shop and ask the tech to work on my motor. He said he was not allowed to, but confirmed that if he was working on a motor with perfect compression he would not crack the block on a 2 stroke.


So I am back to square one, spark, compression, fuel.

Could the timing be so off that it fires when the piston is not at TDC?

 

[Bosunsmate]

I took the Engine to the local Tohatsu dealer.


So I am back to square one, spark, compression, fuel.

Could the timing be so off that it fires when the piston is not at TDC?

Yes, for that you need a timing light and 12v battery. My new timing light cost $15
By the way a motor will start on 60psi out of the water so compression is definitely not your problem.
Its either timing or wet fuel.
Timing light will rule it one way or another spark/timing in or out.
You never said whether you checked those bypass hoses for signs of contamination, thats as quick a job as changing sparkplugs.

 

[panamakid]

Bosunsmate,

I have not checked the bypass hoses yet. I did ask the dealer to do it and shared the wet crank case theory.

I will do it today.

I will say that the motor has less "Bounce Back" than another 10 HP I pulled on. Mine is "smoother"

As if a compression valve is stuck open. I know this is a 2 stroke so that rules that out.



I have only done a timing test on a car, one clamp went on the plug wire the other on the battery.

This Motor has no battery so where does the clamp go?