Tohatsu m40c 40 hp won't start.

sailhard

Cadet
Joined
Sep 18, 2007
Messages
15
I have a '92 Tohatsu 2 stroke 2cyl with under 50 hours.
I've never had any problems with it...but last weekend it suddenly dies on me a few minutes after starting it, and refused to restart.
It acts like the tank vent is closed... it starts initially and runs for a second, then dies. I replaced the gas, I cleaned both fuel filters, checked the hoses...no luck. I inspected the fuel pump, and it looked intact...
I also squirted some carb/choke cleaner in the intake but no luck.

The only other clue I have is the stop switch is missing, so I always stop it by opening the choke..

Any ideas?

ds
 

John_S

Rear Admiral
Joined
Jun 21, 2004
Messages
4,269
Re: Tohatsu m40c 40 hp won't start.

Well, it definitly sounded fuel related until your last sentance. I don't think it is electrical, but very easy to check. Pull they plugs and check for a good strong spark.

If it dies that quickly, it sounds like the carb fuel bowl is not full or a carb restriction. While priming, you can hear the fuel squirting into bowl and detect when the float shuts it off. It should run for minutes, not seconds. The 50 hours are low hours, but given its age and storage time, anything rubber is suspect. I think I'd strart with a good carb cleaning and kit. Might as well do the fuel pump too, its very easy.

PS: I'd also keep a close eye on the pee hole. The impeller (if it hasn't been changed) might have taken a set from sitting over the years.
 

sailhard

Cadet
Joined
Sep 18, 2007
Messages
15
Re: Tohatsu m40c 40 hp won't start.

Thanks,

I changed the plugs last month, (The old ones looked fine ) but I'll check them and for a good spark.

I read in another post that the carb comes off in like 30 seconds...I think I'll try and take it off and give it a good spray cleaning, and if that fails I'll get a carb kit.

How tough is it to install the carb kit? I hear they don't come with instructions and I don't have a shop manual...I rebuilt a holley 4 bbl about 25 years ago but it came with step by step instructons.( a LOT of steps ) I assume the 2 stroke carb is pretty basic...

I need to get that safety switch replaced too but can't find one.

ds
 

John_S

Rear Admiral
Joined
Jun 21, 2004
Messages
4,269
Re: Tohatsu m40c 40 hp won't start.

I did my 40C carb, and it did not come with instructions. I do have a repair manual. I wouldn't claim 30 second removal, but it is fairly easy and straight forward. Cleaning is the most important part of the rebuild.
 

sailhard

Cadet
Joined
Sep 18, 2007
Messages
15
Re: Tohatsu m40c 40 hp won't start.

Great news, I had some time to **** around with it today. I found a chunk of green corosion bridging the gap shorting out my exposed terminals to the kill switch. ( I found this before I checked for spark )

I don't get why every now and then she'd start for a few seconds, but after I cleaned the stuff off the switch terminals I had no problems running it for an hour. I will shut her down with needle nose pliers on the terminals until I can find a switch. Choking it to stop can't be good fthe carb.

I hope it isn't just "behaving" and wants to leave me stuck out to sea...
I have a macgregor 19' powersailer so I can always sail in, but my mooring is a mile or so up a river and through a narrow drawbridge so it could get hairy..

Thanks for the reply john.
 
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