New ish Yamaha Engine

[stul]

Hi
Got hold of a 40 hp 3cylinder Yamaha 1986 (j)stamped seems a good engine so far. (pull start)
Started to fit it on rib this morning,noticed there is a small ruber or plastic pipe ( about 6m/m dia OD)that come,s from gearbox up behind swing arm linkage cannot find where it goes too (about 6 inch long)it has a small tie wrap on it has come adrift some ware but cannot see ware from.
What is its function,is it very important,where does it fit too.any help welcome
Stuart

[ribraff]

I may be wrong but i think this is the pitotstatic tube which is usually connected to the speedo, it is not essential to use it though.

[stul]

Thanks for that
Must have been used at some time
Stuart

[jyasaki]

Originally Posted by stul

Thanks for that
Must have been used at some time
Stuart

Only if there was a speedometer fitted to boat that the engine lived on.

There is a tiny hole in the leading edge of the lower unit, that is connected via the tube you see to another plastic hose that runs to the speedo. As you move forwards, the water is forced into the little hole, and the gauge "reads" the resulting air pressure that is presented to it (the air is trapped, so the water pressurizes the air.) These things are somewhat notorious for falling off the gauge and spraying sea water all over the inside of the console. They also tend to pick up bits of kelp or sand or seashells and become useless (a small drill bit worked into the pitot hole will usually clear that up.)

jky

[Nos4r2]

Let us know how big your grin is when you take it out the first time

[stul]

Work keeps getting in the way, but making progress, brought from Ipswich Sunday fitted to rib Monday, sorted steering an fired it up today, cables for remotes tomorrow hopefully, one thing the kill switch fitted on the back of engine does not work well, how do i check this out does it just short low tension side down to earth, does the switch itself have to be in contact with earth.
Thanks Stuart

[Nos4r2]

Originally Posted by stul

does it just short low tension side down to earth,

Yes

Originally Posted by stul

does the switch itself have to be in contact with earth.

If the switch has 2 wires then no.

[stul]

New Yamaha engine went well, launch at the bacons Conway, on my own, put boat in water of slip, went over to floating pontoon, tied off left running Big M guy in charge down there kept an eye on it, while i went back to park car up. Came back engine ticking over nicely tried a little spin down estuary just over 30 mph top end but with full tank 52 lites, pick up rate in straight line very good, does not like to tight turns might try doel type fins on, think mixture a bit oily used to run 50to 1 this engine has mark on it 0f 100 to1, is there any kits sold that tells you what mixture you have in tank
I added a 10litres of petrol into 3/4 full tank to reduce % abit,
But all in all went went well.
Stuart