I have a 35 tohatsu outboard, fitted new impeller but cant remember the gasket placements ,think mine is wrong as water flow is not enough. Can you help

Yes. It is cooling water.

I suggest you contact Tohatsu.

https://www.tohatsu.com/contact.html


CONTACT US TOHATSU outboard motors

Manuals for Honda Outboards by Seloc 1978 2014

I just looked at 7 different sites and they are saying Max RPM is between 4,500 - 5,050... How accurate is your Gauge?

Prop Pitch will greatly effect MAX RPM.

Page 108http://marine.honda.com/pdf/manuals/31ZW5600.pdf

have you changed the impeller inside the lower unit.

There is copper pipe to redirect water up into the engine.

When you replaced the impeller make the copper pipe is insert onto the engine.

sounds like you need a new water pump impeller.
to access the impeller the bottom of the motor needs to be unbolted and the impeller is fitted to the shaft, it is keyed so it only goes on one way. ( impeller kits will come with new gaskets,grease.O-rings and a new key ). re-bolt the lower unit and test.

c...

There Is a Impeller On The Sea Water Intake Side Driven By A Fan Belt At Front Of Engine ,
Remove Cover Pull Out Impeller Check Key Fit New Impeller And Gasket

yam water pumps are clever the offste centre causes the pump vanes to flex during rotation and at low RPM you have a displacement type pump, at high RPM water pressure forces the vanes to flex inwards and the pump becomes centrifugal, you can fit the impellar either way up so you cant fit it wrongly make sure your gaskets are ok and that the delivery pipe to the power haed is not leaking (try a hose on it) also make sure the little woodruff key or on some models the pin through the drive shaft which turns the pump is fitted ok, not much else that can be wrong!

Yes, I think I know the problem because I have the same motor and mine starts right up every time. When you cold start it, you may not be priming it enough...it doesn't have enough gas. Don't squeeze the bulb 2 or 3 times, do it about 10-12 times. Full choke and it will light right up. On a warm start, you don't need to prime it or choke it. On a semi-warm start, try half choke and no priming.