Tohatsu 50Hp Project - Page 2

watersidemat · 03 December 2016, 08:27

I've been thinking about this more and the visible leak is coming from the uter face of the head. I.e the other side of the head shown in the picture so there no leak on the cylinder side where the combustion happens it's just coming out of the void space between the head plate and the head.

Does this make it less serious so just using a heat resistant silocone based gasket sealant ok as it's outside the actual combustion chamber?

spartacus · 03 December 2016, 10:08

Quote:

Originally Posted by watersidemat

I've been thinking about this more and the visible leak is coming from the uter face of the head. I.e the other side of the head shown in the picture so there no leak on the cylinder side where the combustion happens it's just coming out of the void space between the head plate and the head.

Does this make it less serious so just using a heat resistant silocone based gasket sealant ok as it's outside the actual combustion chamber?

Cylinder head looks as clean as a whistle, no indication of excess head which could have warped it. When you rebuilt the head, did you use a genuine Tohatsu gasket and torque the bolts in sequence from the centre spreading out?

You also mention water droplets on the sparkplugs? That's worrying. What was the cylinder block like when you removed the head. Any evidence of water droplets on the pistons?

watersidemat · 03 December 2016, 10:18

I'll find out about water getting in to the cylinder today when the head comes off, used all genuine tohatsu parts and bolts tourqed in order.

watersidemat · 03 December 2016, 14:30

Cylinders had water in them, the visible leak was caused by one of the thermostat bolts lifting a tiny Nick in the metal gasket and that let the water through.
Heads off and had a second attempt at sealing it, will run water through it later see if it holds but not too confident. We will see!

watersidemat · 03 December 2016, 16:48

Tired again and no visible leak, no sure about the inside, what would the spark plug look like if water was getting into the cylinder?
I have good compression, over 105psi and all three are getting similar compression . Engine sounds like it's running well but it is smoking out the exhaust but could this be just because it's cold outside and it's a two stoke? It's a white smoke.
When I take the spark plugs out there is a black residue that is runny and wipes off clean?

jeffstevens763@g · 03 December 2016, 18:03

Quote:

Originally Posted by watersidemat

Tired again and no visible leak, no sure about the inside, what would the spark plug look like if water was getting into the cylinder?
I have good compression, over 105psi and all three are getting similar compression . Engine sounds like it's running well but it is smoking out the exhaust but could this be just because it's cold outside and it's a two stoke? It's a white smoke.
When I take the spark plugs out there is a black residue that is runny and wipes off clean?

I would say you still have a bit of water in there heating up coming out as steam possibly with it being cold I would run it a bit see how she fairs if it were me
If there was water getting in the cylinder it would run rough as chuff
The residue will burnt oil and engine not hot enough to burn off properly OMO

watersidemat · 03 December 2016, 18:06

I'm going to give it a run on the water and see what happens. If it dies it dies!

jeffstevens763@g · 03 December 2016, 18:16

Quote:

Originally Posted by watersidemat

I'm going to give it a run on the water and see what happens. If it dies it dies!

Just thinking if the thermostat hadn't opened you will get steam till it does my Suzuki does

watersidemat · 03 December 2016, 18:18

Take it that would open once the engine is hot?

jeffstevens763@g · 03 December 2016, 18:22

Quote:

Originally Posted by watersidemat

Take it that would open once the engine is hot?

Yes mate mine took about 5 mins when it was 6 degrees the other week

watersidemat · 03 December 2016, 18:23

OK, I only had the engine idling on the hose pipe for five minutes. Just have to run it tomorrow on the river and see what happens!

jeffstevens763@g · 03 December 2016, 18:27

Quote:

Originally Posted by watersidemat

OK, I only had the engine idling on the hose pipe for five minutes. Just have to run it tomorrow on the river and see what happens!

I would advise to put it in a bin and give it a good run before the river ( peace of mind)

watersidemat · 03 December 2016, 18:29

Fortune favours the brave! It's OK I have a rescue/salvage plan in force! If it all goes wrong I'll be brought back to safety!

jeffstevens763@g · 03 December 2016, 20:10

Quote:

Originally Posted by watersidemat

Fortune favours the brave! It's OK I have a rescue/salvage plan in force! If it all goes wrong I'll be brought back to safety!

Fair enough just make sure you run her until she's warm and the stat has opened before giving her some welly best of luck

watersidemat · 03 December 2016, 20:11

OK cool, thanks all!

watersidemat · 05 December 2016, 21:53

Looks like there is a leak getting into the cylinders, had the head back off and gaskets removed, cleaned down the surfaces and will try again with new gaskets and see if I can get a seal this time round.

jeffstevens763@g · 06 December 2016, 09:28

do you think water might have gone into the crank case from previous leak? not sure if the water could be sucked up during running or as steam when hot? on your last run.

spartacus · 06 December 2016, 12:34

You can test the thermostat in a jug of boiling water. It will open. Any doubt about it working efficiently - then replace. They don't usually fail if well maintained. Thermostats that aren't looked at from one season to the next can get salt deposit build up (assuming you're using the engine in salt water). There's a gasket on the thermostat too - so it needs renewed if you're investigating.

watersidemat · 06 December 2016, 15:59

Quote:

Originally Posted by jeffstevens763@g

do you think water might have gone into the crank case from previous leak? not sure if the water could be sucked up during running or as steam when hot? on your last run.

So even once I put it all back together it may look like it's still leaking only it's just residual water? I guess the water will dry off but it leaves behind an oily gunk in the cylinders, thinking about it now when I turned the engine over with the head off to clean off the pistons more water was sitting in the bottom of the cylinder. Will that water drain off anywhere if I leave it over this week?

watersidemat · 06 December 2016, 16:21

plugs came out looking like this?