Tohatsu 90 TlDI

gazzagary

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Sep 1, 2007
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I have a heavy boat and on a 13inch prop just get to 5150 min RPM range, I am going to get an 11inch prop and this should stop the lugging? My prop has a lot of soot on it and i have been reading up in the causes of this which seem linked to the lack of revs. Should I worry about the soot in the block and what should i do to remove the carbon. i wonder if the guru or some other kind person can respond please. Hours are under 150 so should i be worried? as it is running ok. I use rock oil mp3 semi synth oil.

thanks
 

TOHATSU GURU

Admiral
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Jul 22, 2004
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Re: Tohatsu 90 TlDI

Not familiar with that label of oil, but dropping down to an 11 will boost you up 400 to 500 RPM.
 

gazzagary

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Re: Tohatsu 90 TlDI

thanks guru

should i worry about the soot that may be in the power head if the prop is very black? given the relatively low hours?
 

TOHATSU GURU

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Re: Tohatsu 90 TlDI

I took at look at the oil that you are using. Stop now. It is NOT designed for DFI outboards. DFI outboards require an oil that will atomize and burn up. Your oil meets the TC-3 requirement for lubrication, however it will screw up your injectors and fill your engine with carbon deposits as it was never intended for use in an engine of this type.
 

gazzagary

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Re: Tohatsu 90 TlDI

thanks Elvin
this makes sense as I have had to replace an air injector. The reason I went with this is because I bought Iohatsu semi synth and it said on the back made by rock oil in the uk. I called rock oil and they told me MP3 was the same stuff as the tohatsu but was cheaper. Perhaps they were wrong. I can get the optimax DFI oil easily in the uk. and it appears on the list i found below for tested oils. Is it safe to use this. I guess I need to drain out the oil container on the engine and start a fresh.

Nissan Marine Premium Oil

Pennzoil Complete Marine Synthetic

Pennzoil Semi-Synthetic Outboard Oil

Mercury Optimax/DFI Oil

Yamaha Yamalube 2-M Semi-Synthetic Injector Oil

Bombardier RAM Ficht Oil

Finally is there a product I can add to the fuel to try and de carb the carbon build up this error has caused?

Thanks Gary
 

TOHATSU GURU

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Jul 22, 2004
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Re: Tohatsu 90 TlDI

If it's not on the approved list always run away. What Rock oil say's or even what Tohatsu UK say's is meaningless. If that bottle does not say "Approved for use in 2-stk DFI outboards", then it is not for use in DFI outboards. I wouldn't worry about carbon build up at this point, but a visit to your local auto parts store should bring you to whatever brands of cleaner are sold in the UK. I don't see any one brand of the stuff being better than another.
 

pvanv

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Apr 20, 2008
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Re: Tohatsu 90 TlDI

That's very good advice. All DFI motors require DFI-rated oil, period.
 

gazzagary

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Sep 1, 2007
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17
Re: Tohatsu 90 TlDI

Thanks chaps

I have ordered some Quicksilver's "Quickleen" to add to fuel which i hope will take out some of the carbon i have produced is that ok Elvin? It suggests it can work on DFI too
 

TOHATSU GURU

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6,164
Re: Tohatsu 90 TlDI

I sell that brand...It's as good as anything else and will not hurt your engine.
 
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