Tohatsu 5hp vintage? 1970's??

[Bluedoo42]

Air cooled 2 stroke tohatsu 5hp.. Looking for any help/info I can get on it have tried getting in contact with Japan and Australian tohatsu dealers to no avail. I have already done carby rebuild and looking to replace spark lead also, i removed tank and trying to get this off?? I am no mechanic in any regard and have never worked on engines before but doing this as a hobby. Any information/model year would be much appreciated
....... There is a pin next to centre bolt I'm guessing has something to do with it maybe a key lock of some sought again I am very amateur at this

[Bluedoo42]

Can send more pictures

[m chappelow]

Originally Posted by Bluedoo42

.. There is a pin next to centre bolt I'm guessing has something to do with it maybe a key lock of some sought again I am very amateur at this

The pin that your on about is called a Woodruff key & is usually half moon shape "D " Google woodruff key ") which locates in a slot on both the flywheel & usually a Tapered shaft It stops the flywheel slipping around on the shaft & stops the ignition timing /point s getting out of position , You wont be able to remove the key until you remove the flywheel first , the shaft is usually a Tapered one & the flywheel can be hard to remove or take off , And it needs to come off straight , you can be lucky by slacking the large nut having someone to lift or take the weight of the engine by holding the flywheel & then giving the nut a crack with a hammer ,,, though its easy to knacker the shaft thread or nut . The best way to get the flywheel off is after you have slackened the large nut is to use a proper puller with legs or you can make one from a thick heavy piece of steel plate with 3 holes & bolts to match those on top of the flywheel then tighten them up a little at time but watch the bolts dont go down too far as they can damage or screw themselves in the coil when tightening up .your local garage should have something to fit .

[Bluedoo42]

Thank you very much for your help will let you know how I go

[Bluedoo42]

Got it off and have removed plate but it's not as easy as just disconnecting cable looks like it is tapped on and resin applied, my issue was a cracked boot that had been taped up by previous owner but was arcing out of plug getting shocked if touching it. Maybe I should try to replace just boot? Is that possible? Thinking of cutting back lead a little first? The boot actually just came off easily when I pulled lightly apart lead and boot and found shattered housing when removed tape

[Bluedoo42]

Lead is connected to underside of coil?? Located On bottom of picture. Just thinking prob easier and less complicated just to replace boot

[m chappelow]

Before you put the flywheel back on its not a bad idea to check that no metal filings or anything else is stuck to the magnets on the flywheel& to put a little smear of grease on the cam part of the shaft where the shoe of the points touches( runs around ) ( just below the slot for the woodruff key ) other wise the shoe part will wear down quicker on the points which will make the points gap go wider with time .
Points dont look too bad ?

[Bluedoo42]

Points seem ok but then again I have no idea ha ha need to get a manual im not sure what size the gap should be? I'm assuming I can adjust the arm and rubber shoe, looks like it is reversible both sides in fairly good condition. How tight would you recommend shoe to be against cam? I have cleaned it all up looking heaps better, there was some residue and small pieces of metal filings around I think just from undoing all bolts and such nothing to drastic. Thanx again

[Bluedoo42]

Got it all soughted has been running fine seemed to take a little while to get up to full power though couple 5 minutes before reaching full power. Sounded bit rough missing a beat until hot. Was on the water and it died trying to restart motor seemed very clunky difficult to pull would jam at a certain point almost to much compression!?? With spark plug out pulls freely. Soon as spark plug back in same issue. I did notice the spark plug rattled loose on last run almost fell out when It died c

[Bluedoo42]

Could water maybe got in spark hole or having plug loose have had an adverse affect on engine maybe blown or cracked head? Again I'm no mechanic but put new fuel lines, spark plug, cleaned filters, fresh oil in lower unit,disassembled & re-greased swing arm, new premium fuel in new container with correct oil mix, is starting to become a labour of hate I have tried all basic things I could think of..

[Bluedoo42]

And how big should the points gap be when shaft is spun and fully opened? I still have not found information on the exact model of this 5hp tohatsu,

[m chappelow]

What fuel /oil mix ratio are you using ?
Does it pull over freely without the spark plug fitted .

[Bluedoo42]

50:1 mix

[Bluedoo42]

Yes pulls freely with spark plug out