Tohatsu M90A EPTO

Clawed

Recruit
Joined
Jun 3, 2008
Messages
3
I have a Tohatsu M90A EPTO. Had it serviced, took it for spin and driving along at 30mph for about a mile when it cut out, Had trouble starting but got going, went for about 100 yds and it cut out, bit more trouble getting started went 100 yds and cut out - couldn't get it started so got towed in. At home the motor was missing on the number 2 cylinder, didn't seem to be getting enough fuel, worked throttle lever then motor gave a half hearted cough, not a backfire though, and started running on all 3 cylinders. Put back in water went about a mile at around 30 mph and it cut back to 2 cylinders and then stalled. Started with choke on 2 cylinders, cut out after a few hundred yards, started again on 2 cylinders and we limped back to jetty on 2. Compression tested all cylinders #1 = 40lb, #2 = 130lb, #3 = 130lb - wet tested #1 and no change in compression. Have had a few suggestions such as hole in piston, head gasket, rings shot, cylinder head or cylinder cracked. Will remove head for inspection, but would appreciate any thoughts - are these motors easy to repair - are parts available if required?
 

TOHATSU GURU

Admiral
Joined
Jul 22, 2004
Messages
6,164
Re: Tohatsu M90A EPTO

Parts are available from any Nissan or Tohatsu dealer. I don't believe un-skilled people should work on anything...But, it's as easy as any other outboard.
 

Clawed

Recruit
Joined
Jun 3, 2008
Messages
3
Re: Tohatsu M90A EPTO

Thanks Guru, don't actually intend to do the work myself, only remove head to see if I can see the problem. Maybe busted rings or blown head gasket. If gasket I can replace, but if anything else will get it worked on. Are these motors known to blow crank seals - could this be the problem? Can see top of piston through plug hole and it looks to be fine, but won't know until head comes off.
 

TOHATSU GURU

Admiral
Joined
Jul 22, 2004
Messages
6,164
Re: Tohatsu M90A EPTO

Virtually unknown to blow a seal...But I hear people in California are into stange things:) Sounds like you lost number 1 so that would limit you to:

Block
Piston/Rings
Head gasket
And in theory, a crankshaft.
 
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