overheated tohatsu

[Rogue Wave]

A while back I oveheated my 90 Tohatu ( Toohatso) very badly. despite months of trying to get it right it ain't right! I truly dont know much about boring out and oversized pistons so can anybody tell me what I can do I think it needs a rebore and bigger pistons . I have access to a sweet machinist with his own workshop who would be called my favourite Couzin Steve!

[spartacus]

Got a couple of options here. Either try and source a new powerhead, or as suggested go for a rebore. If you opt for the rebore then you'll need new pistons. You may also need the crankshaft and conrods rebalanced. Depends if the engine siezed, number of hours, etc. The rebore itself involves boring, inserting a new cylinder core or sleeve, honing and polishing. Very specialised job and needs to be completed to factory tolerances. Do you know what caused the overheating - impeller/thermostat? Might be worth giving these guys a call, if nothing more than advice and a quote. http://cgi.ebay.co.uk/yamaha-outboar...item19b8c5aa2b

[spartacus]

Originally Posted by Rogue Wave

A while back I oveheated my 90 Tohatu ( Toohatso) very badly. despite months of trying to get it right it ain't right! I truly dont know much about boring out and oversized pistons so can anybody tell me what I can do I think it needs a rebore and bigger pistons . I have access to a sweet machinist with his own workshop who would be called my favourite Couzin Steve!

Would you adam and eve it. http://cgi.ebay.co.uk/Tohatsu-80-90h...item1e5a230822

[PeterR]

A good link but looking at his other stuff he certainly knows how to charge

[spartacus]

Originally Posted by PeterR

A good link but looking at his other stuff he certainly knows how to charge

True, but a 90hp Tohatsu block and running gear don't come up that often. I suppose the seller could be open to offer. If you had a Fiat Punto - you'd be sorted. He's got enough spare parts to practically rebuild one!