15hp Mariner

[cbruh1]

Hi there,

Just wandering if anyone would have an idea of what could be wrong with my outboard.

Its a 15hp Mariner - 99model.

Last time I took it out for a spin was about 2months ago, and the engine started ok, goes into gear forward and reverse ok.

But when you start to accelerate, the engine just creates no power or revs. Full throttle it wouldn't plane, it normally gets up to 35/40kph with 2 blokes and gear, it was doing maybe 5-10kph with just me in it with no fishing gear or eskie, just fuel and safety gear. It also sounded louder then normal, abit rougher aswell.

Any ideas on what could possibly be wrong, and what course of action I should take. I have been meaning to do this for the past 2months but have been to busy with work and it has just taken the back seat of my thoughts.


Thanks in advance,

Callum

[Noelm]

OK, first things first, can you borrow a complete tank and hose with fresh fuel? next remove the plugs and have a look at them, are they both the same?, do not start pulling things to bits yet, you may introduce another problem, do those things and get back to us.

[FNQCairns]

If it is reving up but going nowhere fast .....prop bush, if not reving well then look elsewhere as Nolem said.

cheers fnq

[Chimo]

Hi Callum

If its not fuel and not a prop bush then it could be what was doing the same with my 9.9 HP Mariner. Half of the power pack was breaking down at higher revs.

Genuine for a 9.9 is $400 non genuine made in Germany I think was $300. The cheaper one works fine and so does the motor now.

Thankfully the OMC BRP Master Tech who does my other motors also does work on the Mariner too.

Cheers
Chimo

[cbruh1]

Noel - spark plugs look the same, no corrosion or stuff like that, also last time I took it out, it was with a fresh tank of fuel and clean lines and filter.

FNQ - Originally thought it was the bush in the propellar but I have taken it off and and it is fully intact. So I don't think its the bush, also it isn't the same as its not reving.

Chimo - thanks for that, is there any way identifying that as the problem.

Thanks for your help so far guys.

[Noelm]

remember last time you were out was when it gave trouble, you MAY have bad fuel, water, dirt anything in the tank, you also may have an air leak or something in the hose, can you borrow a new tank and hose, fill it with fuel (and oil) to try it? it is simple, will test a heap of things in one go, you do not know what it is, so you need to find out what it isn't, positively, OK? and might as well replace the plugs for what they are worth. I am not saying it is bad fuel, or tank or anything else, but you need to do some very easy trouble shooting first, it may well be the power pack, but you do not know, also the plugs would probably look different if the pack was breaking down, but not always.

[cbruh1]

Thanks for that noelm, Last time I took it out, i did all the above as the 2nd last time I took it out was when the engine decided it wasn't going to give me full power and revs anymore.
So I took it home, cleaned the tank, cleaned the lines, cleaned the filters, checked the plugs, put fresh fuel and oil in it (and the tank and lines are only new as the old tank and line had an air leak)
Then took the boat for a run and it still wasn't producing power and revs.

I have no idea what it could be, but I don't think it is a fuel/oil issue.

Thanks for your help so far.

[Blackened]

G'day

Fuel issue and it will just die, power pack and it will just cut out intermittently.

Have you checked the float bowl in the carby? jets free? Partially blocked jet is my bet.

Dave

[cbruh1]

Hi Dave,

Not being a very mechanically minded person, I would not know how to check for those, how do I check the float bowl, and what should I be looking for, also how would I check to see if the jets are free.

Thanks again for your suggestions.

[Chimo]

Hi cb and Dave

My power pack never caused the motor the die. It ran fine at low revs and idled ok too but ran rough and wouldnt give me power when you increased the throttle.

The plugs looked OK too.

Like I said one half of the two part powerpack was breaking down, the crook part was not totally dead which made it hard to diagnose without the correct gear and the skills.

I also drained the bowel under the carby, (NB dont totally undo the bolt under the bowl or the ball bearing will drop into the bowels of the housing ) and in my case draining that did nothing as it wasnt water or dirty fuel

I went thru the fresh fuel, new plugs etc etc things.

In the end I took it to an expert ie the Master Tech who does my OMCs and he diagnosed and got the part and fitted it. If your not an expert; being a drip under pressure dont get the job done!.


Cheers
Chimo

[Blackened]

G'day

Usually with this kind of problem you can tell if the CDI pack is cutting out, Mine was last time, replaced with a good second hand one that was also dodgy. It was cutting out at higher RPM though.

Any of my problems that have arisen has been from blocked jets. I have installed a second inline filter since and no worries.

Callum, best to take it to the mechanic, they will test the CDI pack for you (black box on the port side rear) of your engine.

I have the '00 9.9 merc.

Dave

[Angla]

Can you run the engine under some load , in the dark, with the cowling off and look for pretty little sparks exiting the high tension leads. If it runs perfect, then run it again exactly the same with the cowling on and see if it changes. It could be a high tension lead shorting to the cowling.

That's all I've got

Cheers
Chris

[cbruh1]

Thanks for the help and advice so far guys.

I also would like to give a big thanks to Scott "finga" for kindly giving his time to help check it out this arvo.

He checked over the carby and jets etc. all fine and in good working order.

The next step he thinks is to find a local mechanic or someone who can recomend someone who can test the CDI pack and ignition. Cause today the engine started straight away but after 15-20 secs it slowly dies down and cuts out.

So if anyone can recomend anyone that can test the CDI pack that would be great.


Thanks again.

[Mindi]

unless I missed a post I would be looking more closely at the prop bush before more difficult CDI...i had same problem sort of and visual check just wont reveal shot bush...Solas will tell you in a flash if you can get there....or borrow and try an alternate prop

[finga]

Not a prop bush.
Slowly dies until the motor stops whilst it's in the flush bucket.
Starts brilliant though :D

The carby etc was extremely clean. Not a sign of junge.
There was 3 grains of something in the fuel pump (not torn that we could see) but that was it.
Amasing really. You don't see that every day.

Anyways we did a compression test (brilliant it was) and cleaned everything so that's something that's good.
Wasn't a bad way to fill a Sunday arvo really pulling something apart having a yarn to a good bloke. :)
Cheers Scott :)

[cbruh1]

Cheers Scott.

Its not the prop bush, as its a new propellar I bought from solas, but thanks.