overheating

[gonefeedin]

Hi can anyone tell me why when I get on the plane the motor overheats and stops. The fin above the prop is in line with the bottom of the hull, and the tell tail goes in to a dribble or stops after about 1mile(just noticed this morning) is this cavitation

Thanks kev

[cabfisher]

Hi with what you say eather you have a blockage Or your water pump is in need of replacement ,
Better put it in for service and sooner rather than later
I once had a 6 hp evenrude that had the water pickup behind the prop and after going through a heap of jellyfish it picked up a small pice and a few weeks later it blocked it when i went fast.
the service agent pulled it apart and cleared the water pipe then no more problem maybe this is what is your problem . worth a look aey
Cheers Harry

[gonefeedin]

hi harry
thanks for the reply....its just had a service its the second time this has happend thanks
kev

[gonefeedin]

can not enough 2 stroke oil be a factor 40-1

[ryank]

hey mate.

it sounds like the water empeller. some times you burn this out by the ear muffs u run it on, sometimes they are not tight enough there for not getrting enough water through the motor. or if u go in shallow water alot and pick up sand. your fuel oil mixture has nuthing to do with that side of things.
good luck

[sambos]

there is a grommet up in the block that seals in the feed pipe from your water pump.if its an older motor its common for salt to build up causing it to expand and inhibit the water flow. the motors teltale will operate fine at idle, not at speed.or possibly thermastat buggered

[gonefeedin]

thanks for that will have to get it looked at

[Chris Ryan]

Hey Gone,

My Johno did this. One of the legends of Ausfish - Chimo - helped me with a modification to the thermostat springs to shorten them one rung without cutting them off. Runs cooler at low revs now but at WOT the thing purrs like a kitten. Dunno if this helps but here is the link I made.

http://www.ausfish.com.au/vforum/showthread.php?t=65831&highlight=shudder

Cheers,
Puff

[Roughasguts]

You might just have a blocked tell tale.
Get some line from your line trimmer and shove that in the tell tale see if it un blocks any thing.

Of course nothing like going through the whole cooling system, water pump, thermostat, and a good look inside when you take the thermostat out.

If she looks cloged with salt when you take out the thermostat, well the head should come off for a good clean out.

Is the motor a Yammy?

[BM]

Hello,

What engine is it (model and year)

What hull is it (brand, size, construction)

Cheers

[gonefeedin]

I have got a mariner 25 1985 (aprox)..........
the hull is a 3.8m sportsmancraft fibreglass 1980ish

Can you tell me if there is a site that shows you how to do any maintanance or to check things like the thermostat .because i am a mech dead head

thanks for your help
kev

[wags on the water]

If it's just had a service, I'd be ringing the place up and questioning them.

[Deiter]

Is the motor a Yammy?


I think those mid 80's mariners were Yamaha motors - am i sensing some previous experience with this problem RAGS?

Damo

[Roughasguts]

Hi Deiter, The Yammy's have very narrow cooling channels in the head, (compared to other makes) and doesnt seem to take a long time once started, for the salt crud to completely block the galleys up. End result take the head off and scrape the salt out.

Seems to take around ten years to get a hold though.