Question about 10 hp Mariner O/B

psycho · 27 October 2015, 14:20

I have read numerous times of 10 - 15 hp power upgrades. I am now wondering whether it can be done to mine, and if any of you good people in the know, can tell me what is required to do said upgrade...!

My outboard is a 2004, 10hp 2/ Mariner. The thermostat version.

I have tried google, but it has not given me any answers whatsoever.

Fenlander · 27 October 2015, 15:04

I've had the 10 & 15 at the same time to compare... new carb required for sure as the throat is far bigger on the 15... not a restrictor you can remove either... the whole body is cast in one.

I can't quite remember but you might need to check on a parts diagram for them both to see if the reeds that are directly behind the carb might be smaller on the 10.

camelgas · 27 October 2015, 18:34

legend has it that its just a carb swap !.

Get the serial number off the ID plate and ring your local mariner dealer, they should be able to confirm and price parts for you.

Fenlander · 27 October 2015, 18:54

There are some pics of my two here... http://www.rib.net/forum/f36/mercury...5hp-68735.html

You can see it's a fair reduction in throat area.

I've just looked at the parts diagrams on Boats.net for a 10 & 15 (just one example as you'd have to do it with your own serial number) and the reed block is the same for 10 & 15hp.

psycho · 27 October 2015, 20:15

Thank you for the info guys..!

I see what you mean about the throat clearance.

Worrying thing is, I followed your advice, and looked on boats.net, and my serial number is not found..!

Fenlander · 27 October 2015, 20:27

If you didn't mind posting it (or PM me) and I'll try to look the parts up for you.

psycho · 27 October 2015, 20:32

I dont mind mate, it would be very kind if you could, thank you.

The details are -

S.N 0P290173
10M
2004
Made in Belgium

Fenlander · 27 October 2015, 21:39

Is this yours? Serial no. range looks correct??

10 MAGNUM 0P017000 THRU 0P325499 Mariner Outboard Parts

psycho · 27 October 2015, 22:22

I presume so bud, but not sure. I got that aswell, but if you type in the serial number, it is not recognised. Also, is the 10M a 'Marathon' or a 'Magnum' version?
The only thing that I could think of, that site is for the USA, and on the top of my engine, it says something along the lines of, 'not for use or sale in usa'.....!?!?

I think the best thing to do, is to go and see the local 'Mariner dealer', and then I could get a rough idea of price aswell, and gauge whether it is financially viable to upgrade, or cheaper to just buy a bigger engine....

Many thanks for your time and effort mate, it is appreciated, I will update and let you know, if and when I get answers.

Dave

Fenlander · 28 October 2015, 08:21

Try this one then...

Mariner Outboard Motor Parts by Engine Model

Whichever of Magnum/Marathon you choose it has your serial number range with "Bel" in brackets rather than USA... I reckon they are correct part listings.

Input your serial no. in the box and this website seems to find yours...

http://www.marineengine.com/parts/mariner-outboard/

I think you will find there is a marking on the carb that will ID it.

psycho · 28 October 2015, 08:59

Wow, brilliant thank you mate.

That looks a bit more promising.
When I get 5 minutes spare, I will go and see the marine mechanic armed with the part numbers, happy days.!!!

Fenlander · 28 October 2015, 10:40

Do post how you get on. It will be interesting to see what a dealer has to say. Sadly from my experience there are many who just do not have the experience to really know what's needed for such conversions so prod about in the dark with no more understanding than an owner armed with the above links.

I'm guessing the new carb will be over £200 with a slight risk they get the wrong one which you would never really know. How will you tell if the upgrade produces 10.5hp, 12.5hp or 15hp?

Just taking a guess at £225 for a carb...

There's a Mariner 15 on here that looks tidy... http://www.rib.net/forum/f10/15hp-ma...0-a-70238.html

So if you reckon your 10hp would sell for £625+ then probably it would be better to buy that and sell yours. In truth I'd expect yours to sell for £850+ as next season starts so you could end up with a zero cost swap.

psycho · 28 October 2015, 11:27

Great minds think alike....!

I have already seen that for sale. I am having thoughts about more power, because my last 'Quicksilver 380hd' that I very regrettably sold, (long story) had a 25hp 2/ Mercury on the back, and went like the proverbial, off a slippery stick...!

Since getting this QS 380hd, with the 10hp on, the words of Tim Allen, in 'Home Improvements' keep ringing through my head......'MORE POWER..'

But this is where it gets complicated, my father in law, also owns half of the boat...............

Sooooo, when I started looking at posts on here about changing this part and that part, and getting more power, I tend to get a little excited.
I am going to speak to my mechanic, and enquire whether it can be done, and how much, just out of interest, but will probably sit and wait, enjoy what we have, and buy a bigger engine when the chance arises.........or will I.....?

Neil Harvey · 01 April 2016, 19:52

psycho - did you progress with this at all?
I am also interested in an upgrade, although I just spoke to an ex Merc empoyee, who told me the 10s are more like 12/13hp. Still don't really know if true, but will see how it compares speed wise to my 9.8 Tohatsu

Quote:

Originally Posted by psycho

Great minds think alike....!

I have already seen that for sale. I am having thoughts about more power, because my last 'Quicksilver 380hd' that I very regrettably sold, (long story) had a 25hp 2/ Mercury on the back, and went like the proverbial, off a slippery stick...!

Since getting this QS 380hd, with the 10hp on, the words of Tim Allen, in 'Home Improvements' keep ringing through my head......'MORE POWER..'

But this is where it gets complicated, my father in law, also owns half of the boat...............

Sooooo, when I started looking at posts on here about changing this part and that part, and getting more power, I tend to get a little excited.
I am going to speak to my mechanic, and enquire whether it can be done, and how much, just out of interest, but will probably sit and wait, enjoy what we have, and buy a bigger engine when the chance arises.........or will I.....?

Fenlander · 01 April 2016, 20:07

>>> just spoke to an ex Merc empoyee, who told me the 10s are more like 12/13hp

No disrespect to the guy but just look at the serial no sticker... what HP does it say? That's what it'll be +/- production variations.

Yes the Tohatsu 9.8 vs Mercury XR10 will be interesting... wonder how the prop pitches differ?

And the splash will be interesting as your Tohatsu suffered a fair bit on the riser block left on the old Aerotec... which was OKish with our Mercury 15.

Neil Harvey · 01 April 2016, 20:21

Quote:

Originally Posted by Fenlander

No disrespect to the guy but just look at the serial no sticker... what HP does it say? That's what it'll be +/- production variations.

Yes, I kind of agree, but he said they were more powerful than the 9.9. I have never done that comparison; if it was sold as a 10, the plate would say 10 regardless of actual output. And neither of us can prove it either way, although your speed comparators between the (edit) 10 and 15 might suggest you are right?

Quote:

Originally Posted by Fenlander

Yes the Tohatsu 9.8 vs Mercury XR10 will be interesting... wonder how the prop pitches differ?

No idea, just checked, but I don't see anything stamped on either of them...

Fenlander · 01 April 2016, 21:19

Ahh that's the thing... the XR10 model designation was just a marketing name for a 9.9.

Below is an image of the data plate on my XR10 which clearly states it's a 9.9hp or 7.4Kw.

Anything more is all smoke and mirrors!

Neil Harvey · 02 April 2016, 07:22

Yes, I also saw that, but to my understanding there is a difference between the xr10 and the previous 9.9

Previous 9.9 is same engine as the 8 and I think the 6, so a lower cc.

Xr10 is a downgraded 15 with a higher cc than the previous 9.9

Does that mean it develops more hp? Maybe not. More torque? Maybe. I guess I will never know for sure without measuring it.

Fenlander · 02 April 2016, 09:36

Neil not trying to "prove" your outboard to have less power than you might have hoped... just this tech/mechanical stuff interests me.

Done some more digging with other forums, parts lists and the workshop manual to find more than before.

The carb swap due to the narrow throat casting as well as smaller jets on the 9.9/XR10 is a given. Found out the timing settings are unchanged between those models and a 15. But also found as well as the smaller carb there is a smaller exhaust outlet for which you need to take the powerhead off the leg and upgrade the casting which the powerhead bolts onto together with its integral exhaust tube.

See page 181/182/183 of the workshop manual here...

Boatinfo - Mercury Service Manual for 6-8-9,9-10-15 hp

... where items 10 & 11 are the adaptor plate and tube.

So it seems even with a hard to find used carb or very expensive new one there is still more invasive work needed to make it a true 15.

Of course you could well be right that much of the lower range grunt of the 15 would be present alreday in its XR10 guise. A dealer (lifetime marine industry owner not a fresh faced salesman) told me a good few years ago about the Tohatsu 6/8/9.8 2-stroke range which are all based on the same unit. Talking about the holy grail 9.8 he commented its extra power over the 8 was really only seen at its highest revs so that when popping onto the plane and maintaining a medium cruise speed the 8's performance was very close to the 9.8.

Neil Harvey · 02 April 2016, 22:23

David no worries on the "proving" thing.
I am curious to find out if there is a positive performance difference to the 9.8, but I may never find out.
I also heard about the exhaust ports needing to be upgraded, last night. So for me, not worth the hassle. The Merc will be going on the market, it has to given I will collect a Mariner 25 tomorrow. Not looking forward to the higher weight, but won't be lifting it far or often. It should fly quite nicely in comparison to the 9.8

I'll just have to be light on the throttle