any small outboard guru's ?

[bluepenn]

first off let me say a big hello to everyone,topic is a 7.5 johnson.
its a 8jrcss which i have found to be a 1980 model,it overheated
yesterday and has done some minor,shall we say cosmetic damage,
namely the hand throttle (plastic coupler joining cable to hand lever pin)
and a mount ontop of the motor for the throttle cable too. its still there
just a bit melted,whether that needs replacing or not is still to be determined.
the pin on the throttle let go because someone decided to pack things with
thick grease that wasn't needed,making parts stiff.

i have found some parts online,mainly engine internals,second hand body's
and various other parts on flea bay,nothing close to little fiddly bits. my question
is,do i have to ring some boat shops with my fingers crossed and hope they
have a dusty piece sitting out the back from several decades ago,or is there
maybe an interchangeable part from something else that is maybe still made?

im a complete newbie to this boating stuff but am somewhat mechanically minded.
after it overheated i was told the impellor was probably stuffed as there usually rubber or plastic, i pulled a small triangular housing off which to my surprise had a thermostat,or what was left of one. it had a tonne of shit behind it which i think
was the problem anyway, i still need to hook it up in a bucket of water and see if it
flows,so hopefully the overheating wont be a major problem.

i have a new 15hp yammy in perth (im in broome) but i wont have it till may,we
only got this boat a couple of days ago (our first) and although it was fun even with it breaking down,it would be a shame to have it sit not being used.i would
like to get it going, if anything temporarily the compression seems ok shes just
a bit old and has been sitting. we got the whole thing (3metre tinny,motor and trailer) for like 600 bucks so i cant complain too much,if i could get it running
without forking out too much coin i would be happy.any advice or input would
be greatly apprecciated.

thanks in advance.

p.s this forum kicks ass,so far i have been more of a reader than anything else,
and the fishing up here is terrific,even though the motor was cooking while
it sat to cool my brother was hooking up catfish in the creek on a tiny 4kg telescopic,he doesnt fish much and was having a blast. it was fun to watch.
we had 3 go's of going a short distance then letting it cool,ended up about 200m
from shore and eventually having to get towed. was still a fun day.;D


thanks guys. ash.

sorry for the short novel,first post. ::)

[Noelm]

dont want to scare you, but if it got hot enough to melt parts around the engine, you may have some rather sad news waiting for you if/when you get it started! but you never know, those old motors are pretty tough.

[kizza1]

dont want to scare you, but if it got hot enough to melt parts around the engine, you may have some rather sad news waiting for you if/when you get it started! but you never know, those old motors are pretty tough.

id say its possibly got a blocked water tube grommet. that is the second most common things to cause overheating. the first being the waterpump impellor which is located in the top of the gearbox.
pull the gearbox off. pull the thermostat housing off. then blast water up the watertube from the gearbox end and try blast out all the calcium build up. while the gearbox is off replace the waterpump.

[testlab]

after it overheated i was told the impellor was probably stuffed as there usually rubber or plastic, i pulled a small triangular housing off which to my surprise had a thermostat,or what was left of one. it had a tonne of shit behind it which i think
was the problem anyway, i still need to hook it up in a bucket of water and see if it
flows,so hopefully the overheating wont be a major problem.


What kind of 'shit'? Shells, sand, metallic particles, rubber, mud?

After it sitting around for so long unused the impellor will be next to useless. Its last dying gasp was probably pushing a gut full of crap up to block the t'stat. Flush it out as suggested and then get a new impellor and perhaps even a water pump housing.

When running it in a drum make sure there is a good strong stream from the tell-tale and there is water exiting from the nostrils on the back of the lower housing. If it didn't seize under heavy load or high speed you may be lucky.

[finga]

I'd really like to see that motor.
I've never, ever seen one that's melted plastic due to water not running through.
Seen them with melted plastic that been heated due to fuel imitating a bonfire though.
You'd be a brave man to spend money on that motor if it's been heated to that extent because of lack of water I reckon.
Imagine what the big ends would be like?? They're only white metal. And the crankcase is only alloy.

[cormorant]

I'm with finga . Any chance the parts were melted before this event or the parts had come off another motor that had had a fuel fire under the cow or a earlier fire on this motor. The only ones I have seen with melted parts were well seized.

Hope you get lucky with it .

[bluepenn]

What kind of 'shit'? Shells, sand, metallic particles, rubber, mud?

After it sitting around for so long unused the impellor will be next to useless. Its last dying gasp was probably pushing a gut full of crap up to block the t'stat. Flush it out as suggested and then get a new impellor and perhaps even a water pump housing.

When running it in a drum make sure there is a good strong stream from the tell-tale and there is water exiting from the nostrils on the back of the lower housing. If it didn't seize under heavy load or high speed you may be lucky.


thanks for the reply's,
i would say it was like mud particals that have dried,best i can describe
it looked a bit like milo,definatly not metal though. luckily we werent hammering
it when it stopped,it did try to seize but we turned it over by hand when it did.

she must be pretty tough because it runs,there's a slight knocking sound but
i think thats been there from the start. water is definatly running through
it now and its keeping cool. might be worth only taking the boat out when my
mate takes his out, just incase something happens,we only intend going
100 or so meters out anyway.

heres the melted plastic bit,all the other plastic on the motor is ok, just
this part. its still functional (holds cable) just doesnt look the best. (below)
http://i735.photobucket.com/albums/ww360/the20valveman/Ashsphotos023.jpg

this is the part of the throttle that broke (below),this holds the cable, and the pin
runs on two small channels in the handle. if all else fails i might be able to use
a brake lever from a bike. do think i could find this part? i know ile be taking
a risk taking it out but if we dont thrash it,hopefully we can get a few more
miles out of her. just run it into the ground until my yammy gets here. it needs
new plugs too.
http://i735.photobucket.com/albums/ww360/the20valveman/Ashsphotos024.jpg


heres a short video of it going- http://s735.photobucket.com/albums/ww360/the20valveman/?action=view&current=Ashsphotos025.mp4 (http://s735.photobucket.com/albums/ww360/the20valveman/?action=view&current=Ashsphotos025.mp4)

definatly built these thing tough.

apperantly evenrude parts fit,some of them anyway.
not sure wether i should replace some of the parts on it or
just run it as is.dunno.

thanks guys i really appreciate the help.
Ash.

[tunaticer]

The vid shows a very weak amount of water flow through your motor with nearly no water coming out of the leg and a tiny flow through the tell tale. I would drop the leg, remove the water tube and check the condition of the top seal for the tube as well as clearing the tube, replacing the impellor, remove the telltale fitting from the powerhead and giving the motor a very strong flush out.
The "dried mud" you encountered is very worrying as you found the easiest accessible deposit of it. Personally I would flush with high pressure from both the feed tube and from the telltale fitting reversing directions of flow half a dozen times to try and dislodge anything remaining. Chances are you will not dislodge some of it creating hot spots in the cylinder & or head.

That being said tho, I rebuilt a 6hp Evinrude that overheated almost to seizing, It runs like a champion ever since and I think punches above its weight still.

Get the water gallery as clean as you can before you do anything else.

Should not be hard to get a tiller handle assembly second hand, there were millions of Johnnos and rudes that used the same handle.

[bluepenn]

The vid shows a very weak amount of water flow through your motor with nearly no water coming out of the leg and a tiny flow through the tell tale. I would drop the leg, remove the water tube and check the condition of the top seal for the tube as well as clearing the tube, replacing the impellor, remove the telltale fitting from the powerhead and giving the motor a very strong flush out.
The "dried mud" you encountered is very worrying as you found the easiest accessible deposit of it. Personally I would flush with high pressure from both the feed tube and from the telltale fitting reversing directions of flow half a dozen times to try and dislodge anything remaining. Chances are you will not dislodge some of it creating hot spots in the cylinder & or head.

That being said tho, I rebuilt a 6hp Evinrude that overheated almost to seizing, It runs like a champion ever since and I think punches above its weight still.

Get the water gallery as clean as you can before you do anything else.

Should not be hard to get a tiller handle assembly second hand, there were millions of Johnnos and rudes that used the same handle.

thanks mate for the heads up, i will give flushing it a go
and if i get time maybe i will disassemble,my brother just bought
a 3.85 big boy brand new, with a 25 merc on it so the little creek
goer will be on the back burner for now. thanks again.