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Newbie seeking help with Japanese Mariner

Mennace

Mennace

New member
As I can imagine a lot of first posts are for seeking help, I'm unfortunately going to be no different.

Very long story short, my neighbour left this beautiful thing abandoned in his backyard for 6 months. I spoke to the landlord and he said I may take any of the obviously neglected items from behind there, and this is where my story starts.

Introducing the Hydra-ski! https://imgur.com/60jeAf1

A bit of background from me: Many many many moons ago my Dad used to own a house on a lake in South Africa and we had a speed-boat with a 200hp Mariner on it. It was a beaut. I was about 8-10years old at the time, so I don't remember too much, but it was the start of me loving boats and outboards. Fastforward to now, I'm 25years old, I'm a software developer, and my main hobby is golf. So, far from anything that actually requires the use of my hands. However, I'm not shy of a challenge.

So I got the boat in my driveway, gave it a scrub, and now I've got this: https://imgur.com/uBpZlk0

Boat wise, I'm not too fussed as I've figured most of it out without hassle.

Outboard wise, I'm at the mercy of you guys.

What I know so far: It's a 1980'ish Japanese made Mariner. 2 stroke, 20hp. Exhaust comes through the prop. Googling '6a9 outboard' seems to give the nearest results to it, but no direct matches. Here's the only label on it: https://imgur.com/sUtOxXU

I'm trying to get this motor to run because my ultimate goal is to actually take this out on the water. I've never seen anything like it and wouldn't want to just hand it off to someone to let them have all the fun.

What I've done so far (Please note that 99% of my knowledge comes from either reading about it online or YouTube):

* Check the stator's resistance (resistance seems near to similar engines, but can't find manual for exact reading)
* Made sure the kill switch was working as intended so that it wasn't shorting out the ability to start the motor
* Cleared out the fuel filter
* Cleaned the carburetor to the best of my ability with carb cleaner
* Got a new fuel line, fuel tank, and hooked it all up
* Replaced the gear case lubricant
* Bought marine grease and greased what I best found I should

Once I spent about a good two days of researching, watching online, and fiddling, I got it to start... using carburetor starter spray. I went back to checking fuel filters and such and realised I could've done a better job as I had the dark tea colour fuel. Once I cleaned it again, I got it to start and run under its own power (with muffs on, of course), for about 30 seconds. During that time I observed a milky, and oily to the touch, liquid coming out the prop area. It was a reasonable amount of liquid coming out and it was quite consistent. From this I then read up that it's possibly because I'm getting water in the oil and it's causing it.

So here's what I'd like to ask:

1 - Is water in the oil/fuel mixture the result of water getting in there, and does this mean I should replace seals? (I'd have no idea which ones to target)
2 - Could anyone recommend a place to query about a motors manual this old? I've love to be able to test the cylinder pressure or maybe replace the carb (but I've got no idea of fuel spray rate that it would require).
3 - Any advice for things I should check/learn about?
4 - What should I name 'it'?!


Many thanks!

*Edit - Here's any/all photos I have of the project so far: https://imgur.com/a/OznkK
 
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Does it smell like gear oil or fuel? If the gear oil is not milky and the engine runs good take it out for a romp. It could be old oil in the exhaust housing running at high RPM will blow the cobwebs out. Use the serial number for looking up parts it is the bottom number just find the range it fits inbetween. Thats alot of motor for that boat be careful it should fly.
 
kimcrwbr1 said:
Does it smell like gear oil or fuel?
Click to expand...

No, I can't say it had a distinct smell that I could smell. I might need to spin it up again to see specifically if it does and catch a sample in a cup.

kimcrwbr1 said:
It could be old oil in the exhaust housing running at high RPM will blow the cobwebs out.
Click to expand...

When I said I got it running for 30 seconds, I should've probably mentioned that it's the longest I got out of it. It unfortunately doesn't sustain itself under it's own power entirely just yet :(

kimcrwbr1 said:
Thats alot of motor for that boat be careful it should fly.
Click to expand...

...and can you believe the hull actually has instructions on it that say the max engine that should be on it is 30hp?! I mean, I'm a little silly but I'm not toying with that deathwish.
 
Spunds like it needs a good once over. First off do a compression test before spending any money. If the compression numbers are good pull the carb and put in a kit #84773M. Take it completely apart except the butterfly and soak it overnight in carb cleaner. Blast the circuits good with high pressure water and blow dry with air. Do not put finger pressure on the float to adjust it pull it out and bend the tab then check it upside down the float should be level with the carb. preadjust the slow needle 1 1/2 turns out from lightly seated. It is a good idea to replace the fuel lines in the motor at the same time. Clean the fuel pump and if the diaphrams are stiff install new ones. I could not find a kit for the fuel pump you will need to do it piecemeal.
 
haventaclue said:
You have a 1985 Yamaha Mariner Manual start, Short shaft.And $30 would be money well spent on a manual.marineengine.com do ship manuals overseas.
Click to expand...

Thanks for this, I'll be putting an order in ASAP :)

kimcrwbr1 said:
Spunds like it needs a good once over. First off do a compression test before spending any money. If the compression numbers are good pull the carb and put in a kit #84773M.
Click to expand...

I've asked a few friends and I will be able to lend one from a friend at the start of next week. I'll let you know how it goes!

kimcrwbr1 said:
Blast the circuits good with high pressure water and blow dry with air.
Click to expand...

Do you mean literally spray down the engine with clean water? My grade 5 science is telling me water + electricity = bad. Do outboards negate this general rule?
 
When you rebuild the carb blast it after you soak it in carb cleaner the water scours the circuits good and then blow all the water out and put it back together. Yea I do spray a engine with the hose after giving it a coat of degreaser then start it up so it dries out good. Just be careful to avoid getting water under the flywheel. Be sure and shoot some grease in all the zerts marine grade grease at least once a year. It is also a good idea to take electrical connectors apart and clean with electrical cleaner then put some dielectric grease on them when you put them together to protect from moisture.
 
Nice little boat! What lake in South Africa are you talking about?

Anyway I have the Yamaha version of this motor and it is a pretty straight forward engine ..... firstly did you mix the fuel with 2-stroke oil ratio 50:1?
Did you check the gearbox oil in the lower unit? The only ever problems these motor have is carb related, if you clean the carb perfectly (consider giving it a ultrasonic bath) it wil run first time every time.
 
deejaycee_2000 said:
Nice little boat! What lake in South Africa are you talking about?
Click to expand...

I should've actually said dam, not lake! Regardless, it was Kwaggaskloof Dam, right next to Worcester in the Western Cape :)

deejaycee_2000 said:
Anyway I have the Yamaha version of this motor and it is a pretty straight forward engine ..... firstly did you mix the fuel with 2-stroke oil ratio 50:1? Did you check the gearbox oil in the lower unit? The only ever problems these motor have is carb related, if you clean the carb perfectly (consider giving it a ultrasonic bath) it wil run first time every time.
Click to expand...

Yip, I mixed the oil in that ratio and I bought new gearbox oil to replace the stuff that was in there.

At the moment my list of 'to-do' includes:
* Clean the carb again (I think I did a pretty weak job the first time round)
* Get a pressure test on the cylinders and then go from there
 
Oh yes, I spent alot of time at Kwaggaskloof as I grew up in Worcester!

These little motors are great, the carb is pretty much the only thing keeping it from running right, I only ever changed 1 coil ever on mine.
Best way to clean the carb (if you do not have or know someone that have a ultrasonic bath) is to disassemble it and soak it in carb cleaner over night and then blow out with compressed air. Make sure the jets are open and clean. The air/fuel mix screw should be set at 1 & 1/2 turns outwards from soft stop and then slight adjustment from there until it is perfect.
 
deejaycee_2000 said:
Oh yes, I spent alot of time at Kwaggaskloof as I grew up in Worcester!
Click to expand...

Just because I know how small this world really is, I'll take the gamble and ask if you know anyone by the surname of Krouwkam (family friends of ours that run a attorneys practise down there to this day) or if you were around the ski club in the time I was there (this was near the 2000's), then hopefully Herman Fick might be a name that rings a bell to you (My Dad)

deejaycee_2000 said:
The air/fuel mix screw should be set at 1 & 1/2 turns outwards from soft stop and then slight adjustment from there until it is perfect.
Click to expand...

Between the next two photos, could you possibly tell me which the air/fuel mixture screw is?

https://i.imgur.com/4EDDPKP.jpg
https://i.imgur.com/XcgjN64.jpg

Greatly appreciate the advice!
 
It's finally time for an update!

Firstly thanks to kimcrwbr1 for the advice and the part numbers. I ordered a cylinder compression test kit as well as the carb kit. I replaced all the parts from the kit onto the card and I'm pretty sure it cleared up a lot of the fuel issues I was having.

The compression test showed the following results:

Top cylinder: https://i.imgur.com/brhJmrK.jpg
Bot cylinder: https://i.imgur.com/3EmZkZR.jpg

As best I could read, they're sitting at 90 and 95 psi. Now, since I don't have the service manual I can't figure out if that's right. One website says anything below 100psi is garbage while other members on the forum have said they've gotten below 50psi and it still runs fine. Bearing in mind that the pressures are equal enough, in 4 degrees C of weather, I think I'm happy with that.

Now moving on to thank deejaycee_2000 for his advice. I was paranoid about my fuel mixture and his comment just made me chuck my last batch of fuel and redo it, just in case. Again, making sure that it's less likely to be a fuel issue. It also prompted me to clean out the fuel filter. I ended up taking the bowl out, pouring out the fuel in it, and then putting it back together.

Where we're at now with the help of the forum:

First and foremost, I got it running. Without fuel started. I'm adding in the full stops here for dramatic effect as it was such a huge moment for me in my journey of learning how this all fits together.

I tried a few more times, and this is how it would run: https://www.youtube.com/watch?v=zXB8ny1o99U

So as you can see, 10 seconds, it starves of fuel, and then dies.

That was earlier in the afternoon and by the evening I could get it running indefinitely with the following trick:

1 - Close the choke and pull two/three times.
2 - Open the choke and pull, it would start by the second pull.
3 - After 5-10 seconds (when it sounds like it's thinning out), close the choke 2/3rds or 4/5ths of the way until it responds again.

Once I was fiddling the choke while it was running it seemed to be okay and could run as long as I was doing it.

I've tried going to the internet to try and figure this out myself but the utter spread of information is immense and I don't know where to start.

...so once more I come to the marineengine forum and kindly ask, if someone could either tell me what I need to adjust to get this fixed or where I could go and look to find out myself it would be greatly appreciated.

Once again, thanks to everyone that's helped me thus far.
 
Sounds good.Check your fuel pump diaphragm.
Did you blow compressed air through the carbs? It only takes a small grain to create a problem.
 
haventaclue said:
Sounds good.Check your fuel pump diaphragm.
Click to expand...

I did, there were no tears or obvious deformities, so I put it back as it was. My only concern was that the gasket seemed a little worn and should be replaced (I've already got the part on order).

haventaclue said:
Did you blow compressed air through the carbs? It only takes a small grain to create a problem.
Click to expand...

As obvious as this step sounds, I didn't unfortunately. Guess it's time to take it off again just in case and blow it out!
 
The compression is good for that age motor, your readings suggest you have about 300 od hours on the motor, and will still be good for many years if you take care of it.

From what I hear from your youtube video .... your carb is not quite there yet, you need to make sure all the jets are open, float hight needs to be perfect and air/fuel mix adjusted correctly.
 
Hi mate well atleast you have the good motor I swear on these 1977 mariner Yamaha I have 3 spare and one I have just built from the ground up and a lot of the parts were readily avaliable from this web side the prices blew me away and it took 4 days from there to my hands 4 days later in Brisbane Australia. The blokes here have the knowledge to help you so give it a go. They also have workshop manuals I couldnt wrap them any better.
 
The December update

The good I've gotten the engine running on its own 'relatively' well. It doesn't stay running though.
The bad I found another part that I need help identifying 'cause the internet doesn't seem to have it anywhere.
The lesson Carb cleaner HATES rubber seals. Gotta order a new one. Damn it.

So, with Winter in full force in the UK, it's been a bit hard working on the boat. However, I did get some time tonight and I've made some progress!

What I've done since the last update:

Multiple bits of cleaning (including the fuel pump) and taking a lot of time to just try and understand how things work.
I put PTFE tape along the thread of the fuel filter as I had a bad leak there (which I think lead to some pressure loss in the fuel)

Here's a video of where I got tonight:



So, I've got 2 questions:

1 - What's peoples first reaction upon seeing how that engine runs? Bear in mind that without toying with the throttle once in 10 seconds means it's going to cut out.

2 - I've cleaned this screw out on the carb, but I've got no idea what it is or what it does (it was jammed with old oil though).

The screw: https://imgur.com/9kwArCr
Its location: https://imgur.com/A7uhDP3


Thanks again for all the help chaps!
 
"When in doubt, reboot!"

My bet is that you have bad crankcase seals, hopefully the top one (easy to change).

Jeff
 
fastjeff said:
My bet is that you have bad crankcase seals, hopefully the top one (easy to change).
Click to expand...

Thanks for the response Jeff!

I hope you don't mind the naivity - but why do you say it's the crankcase seals? How would that affect the running of the engine?


Thanks!
Dennis
 
And the screw is a drain for the bowl.
Jeff is probably right about the crankcase seal,and I know you checked it for obvious damage,but I'll harp back to the fuel pump diaphragm,hold it up to a light source,there may be a pinhole in it.
 
I finally have an update.

After December holidays, Christmas, and figuring out if I wanted to even endeavour on this struggle, I decided to persevere, and I'm somewhat glad I did.

Here the engine is running! On its own. No tinkering with the carb as I try keep it going. No flicking the throttle constantly. It LIVES.... poorly.



...unfortunately, I have no idea why it's running like this. As you could imagine, trying to google, 'outboard running weird' doesn't return many results at all, so I'm turning to you, the professionals, my leaders, to try and help me figure this one out!

Thanks again for all the help I've gotten so far!

For anyone wandering: I got a ultrasonic cleaner to clean out the carb as well as a refurb kit. I also got a new fuel line from the tank to the engine. I think these small things really did make all the change.
 
Wow you made alot of progress, you are almost there, I can hear there is still a slight miss ..... give the carb another ultrasonic bath (I also have one and it is great but when it comes to tiny jets it doesn't always get all the muck out the first time) if it idles the same I would look at the timing and then if there is no change I will have to agree with the other's on a leaking crank case seal - although it will not idle at all if it was a leaky crank case seal .... on low rpm that is ...
 
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