2010 Tohatsu 30hp stalls periodically and won't start for a day

[Bumbaquat]

So I've got a 30 hp Tohatsu that runs great for 8 hours one day then the next will run for 30 minutes then stalls out and won't start for about 12 hours. Compression is 150, 130, and 130. Seems to have spark when it will not start and plugs look dry. Checked all the normal suspects. About to pull the head and change head gasket. Does it seem to need it with that difference? Anyhelp woudl be appreciated!

 

[pvanv]

Re: 2010 Tohatsu 30hp stalls periodically and won't start for a day

What is your actual model/serial? No, it's probably not a head gasket, but that 20# compression variation should be confirmed. You may have rings that are worn a bit differently, or there may in fact be some other issue. If suspecting uneven compression, always re-double-triple check your numbers, and run a leak-down test (on 4-strokes) to get a better picture of overall health of the motor.

 

[TOHATSU GURU]

Re: 2010 Tohatsu 30hp stalls periodically and won't start for a day

Your best bet would be to take the engine into an authorized dealer...The engine is new enough so that it should be covered under warranty...And with that compression the engine has serious problems.

 

[pvanv]

Re: 2010 Tohatsu 30hp stalls periodically and won't start for a day

Your best bet would be to take the engine into an authorized dealer...The engine is new enough so that it should be covered under warranty...And with that compression the engine has serious problems.

Good point, missed that. And, if the motor is a North American model, it should be an MFS30B, equipped with EFI... Not a unit that the average shade tree mechanic has the proper equipment to diagnose.