water in cylinders

[infinityYS]

I'm missing something obvious here.
Background - yamaha 90 2 stroke overheating. New water pump, then thermostat, popit valve and heat sensor. Then pulled the exhaust cover, inner plate, head cover and head. Did the dirty work and cleaned all the water passages. (no wonder it was overheating). Bought new gasket set. Cleaned all gasket mating sufaces adn gently surfaced them with fine sandpaper on a flat paint stick. Carefully reassembled everything, proper torque and sequence (no brainer). Engine started right up as it should. Add cooling water from the muffs and the cylinders flood with water - all equally very wet, saturated. Pulled head, dried everythign off, oiled cylinder walls, reassembled, started = safe. Checked assemble of exhaust inner and outter plates, gasket surfaces, couldn't detect any leakage.

I'm stumpped...any ideas would be greatly appreciated!

[99yam40]

Hole do to corrosion somewhere or gasket mess up is my guess.
Surfacing with a paint stick is not the best way

[robert graham]

Maybe when you cleaned/removed those cooling passage deposits it uncovered a corrosion pin hole that was previously covered with calcium/salt/minerals...could be difficult to find but you'll have to find it and repair it....back to the shop!...good luck and keep us posted with results.....

[madharchod]

its a very cheap option to replace the cover as it has so many passages that where the pin hole is you wouldn't know so better of replacing th4 cover

[tritontr20]

Overheated and leak

you may want to check;

1. No water in fuel and do a compression check!

2. Ensure head bolts torqued correctly and in sequence.

3. Take straight edge metal ruler to check for "level and flatness of the head and cylinder head mating surfaces.

4. Ensure that the gasket set was correct one and current - installed correctly some have a certain side to be against the cylinder head.

5. Some machine shops can dye penetrate a part to find leak as well.

just my 2 cents.