My New 15 HP

[Bigplumbs]

Before I could get round to testing to see how well my 9.8 Tohatsu 2 stroke (27KG weight) would plane my new Honwave T38IE another of the Holy Grail of engines became available only 20 miles from me (which in its self is a miracle) So I decided to add to my equipment this 15HP 2 Stroke Mercury (34KG) which I am certain will plane the T38ie well.

It is ok to lift and carry a short distance.

I got it for what I consider a good price and it seems to run well and pump water fine. Real test will of course be on the water.

The tick over is a little fast but I can sort that and it backfires a couple of times when first started but that soon settles down. My 60 hp on my rib does the same

Heres hoping it will be a good purchase. Short video of it running

https://www.youtube.com/watch?v=CUh-TjiNV6c

Dennis

[Fenlander]

BP a desirable motor and looks genuine condition. I've owned three so know them well.

If it pumps water like that at a normal speed idle looks like the thermostat has been removed because their proper tell-tale behaviour at idle is to have an erratic stream showing the stat is working.

None of them backfired at all... they were very even tempered for a 2-stroke. So I'd be thinking of a routine look over with new plugs, check leads, check timing, set idle to correct speed, set mixture and check it has a stat.

But these are minor things for a new to you OB... they so often need checking through even if from a dealer.

Look forward to hearing how it goes on the T38.

[Bigplumbs]

Originally Posted by Fenlander

BP a desirable motor and looks genuine condition. I've owned three so know them well.

If it pumps water like that at a normal speed idle looks like the thermostat has been removed because their proper tell-tale behaviour at idle is to have an erratic stream showing the stat is working.

None of them backfired at all... they were very even tempered for a 2-stroke. So I'd be thinking of a routine look over with new plugs, check leads, check timing, set idle to correct speed, set mixture and check it has a stat.

But these are minor things for a new to you OB... they so often need checking through even if from a dealer.

Look forward to hearing how it goes on the T38.

Backfire was only 3 - 4 times after start. I will test it first before I start pulling it about. I am a great believer in if it aint broke don't fix it

[Bigplumbs]

I assume it is 50:1 Mix Petrol.


I was also running it on quite old fuel to be honest

[Fenlander]

Double check but all mine were 100:1 with handbook advice to run on 50:1 for commercial use. I ran mine around 75:1 to 80:1 as the best balance. They had 100:1 stickers on them.

Yep get fresh fuel for your outing before you judge it fully.

[Bigplumbs]

Tested it in my make shift tank to shift into forward and reverse. All seemed to work ok but I have to urn it slightly to reverse and then back a bit again to shift into Neautral. Cant see a sticker on it re the fuel mix. Lost in the mists of time I suspect. Once warm it starts a dream (half a pull) with no backfiring.


I agree the tell tale is rather fast I will check if it has a thermostat.


Smoke a bit but then I find that with all 2 strokes in a test tank


Dennis

[Bigplumbs]

Found what I am pretty certain is the instruction manual for this engine


http://www.baads.org/wp-cms/wp-conte...nual_PART1.pdf


On Page 1A-3 It says 50:1 mix assuming this is the correct manual


Dennis

[69cmw]

Plumb I have the same engine, I will check what mine says on it for you later today

[Bigplumbs]

Originally Posted by 69cmw

Plumb I have the same engine, I will check what mine says on it for you later today

That will be very useful thanks.

Dennis

[Fenlander]

>>> pretty certain is the instruction manual for this engine

You can't go wrong re keeping the oiling up to scratch with 50:1 when not sure but where approved for 100:1 I found they trolled for periods better nearer 75:1 and of course less smoke.

It did depend on year with the later ones being 100:1. If you download a 1997 manual it refers to 100:1. The manual you have linked to is for 1986-on models.

So to be sure if interested in running a little less oil you need to know the age of yours.

[Bigplumbs]

Originally Posted by Fenlander

>>> pretty certain is the instruction manual for this engine

You can't go wrong re keeping the oiling up to scratch with 50:1 when not sure but where approved for 100:1 I found they trolled for periods better nearer 75:1 and of course less smoke.

It did depend on year with the later ones being 100:1. If you download a 1997 manual it refers to 100:1. The manual you have linked to is for 1986-on models.

So to be sure if interested in running a little less oil you need to know the age of yours.

Very interesting I cant seem to see the age I will have to do more research.The guy I bought it off said 100:1

[69cmw]

That’s out of the instruction manual I got with mine

[Bigplumbs]

Originally Posted by 69cmw

Attachment 127000

That’s out of the instruction manual I got with mine

Many thanks. Now I have a dilemma. Need to find out what year mine is and I cant seem to locate the seriel number at the moment

[69cmw]

Mine has the same decals as yours and I think it’s around 1998

[Bigplumbs]

Originally Posted by 69cmw

Mine has the same decals as yours and I think it’s around 1998

I am starting to think that mine is indeed post 1997 because of several things I am finding.

If it is not too much hassle could you please post a pic of your seriel number location/plate as I cant seem to track mine down.

Thnaks

[69cmw]

Originally Posted by Bigplumbs

If it is not too much hassle could you please post a pic of your seriel number location/plate as I cant seem to track mine down.

Thnaks

I’m not home, but it’s a small silver sticker below the bottom engine tray next to where the silver gear linkage is.

[Bigplumbs]

Originally Posted by 69cmw

I’m not home, but it’s a small silver sticker below the bottom engine tray next to where the silver gear linkage is.

Thanks

Mine is missing... never mind

[Max...]

Like Fen' I run mine 75:1. Book always says 50:1 private, 100:1 commercial IIRC.

The gear behaviour you describe is the same as mine...

http://www.rib.net/forum/f36/merc-ma...ent-78578.html

...as is the tell tale, on tickover it will cut in and out but mostly out - on anything else, ie a fast idle or more it should be on all the time but never shoots out a huge jet like other 2 strokes I have used.

All in all though (and I'm always going on about it!) easily the best small 2 stroke made IMHO - super light for a 15 and the tilt/trim system and tiller gear change is something I would really miss on any other engine. I've had Tohatsu 9.8's and Yam and all had issues - unlike everyone else the 9.8 was a real PITA for us.

This was the link I always used for the full workshop manual but seems down:

http://boatinfo.no/lib/mercury/manua...0-15.html#/242

[Bigplumbs]

Max. I have been messing around with it today and I am quite impressed. Just need the weather to imprive a bit so I can get it out on the water.


Dennis