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TIME TO REVISIT THE 60HP & 40HP....59 CU. IN. 2 STROKE MERC!
http://ww.w.hpbc.ca/viewtopic.php?f=19&t=4261
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Author:  Hounddog [ January 1st, 2020, 11:41 am ]
Post subject:  TIME TO REVISIT THE 60HP & 40HP....59 CU. IN. 2 STROKE MERC!

When the motor raced in FV in stock form it was the quickest LeMans start runner to the first pin.
In oval race set up it was a 65 to 67 mph runner. On the lake 69 to 70 mph.
Be careful the 59 cubic inch motor started in 1998.....prior early 1990's motor was 52 cubic inch up to 1997
There are more 52 cubic inch short shaft motors around than 59 cubic inch...likely you can use some short shaft 52 parts
There are two different mid and lower unit styles....1998 and early 2000.
early version
https://img.tradingpost.com.au/56RKZ2NG ... 40x480.jpg

later style mid and gearcase
http://www.2040-parts.com/_content/item ... 42/001.jpg


BIGGEST WEAKNESS:
- carrier failure...bolts would come out
- prop shaft.....they break
- only 115 to 120 compression because of design

BIGGEST PROBLEMS:
- finding a short shaft model
- you could only get 15 over pistons...most rebuilds required a new block
- Mercury parts are VERY COSTLY.
SO MANY WERE NOT REPAIRED DUE TO COST.

UPDATE:
I noticed on EBAY there are now 30 over aftermarket pistons.
https://www.ebay.com/itm/NIB-Mercury-30 ... SwH4lcbUlE

Blocks
https://www.ebay.com/itm/Mercury-Outboa ... SwDXpdWvVE

You can get get custom 160 compression pistons....raise hp from 60 to 80
http://www.boatracingfacts.com/forums/a ... 1510534709

SO THE GOOD NEWS IS YOU CAN REPAIR THEM NOW FOR LESS MONEY
Short shaft mid sections are available new.??
https://www.boats.net/product/mercury/8 ... ef346f7195

This one will work
It is used on the overseas triple
https://www.boats.net/catalog/mercury/o ... aust-plate

And the same part is used on the North American twin
https://www.boats.net/catalog/mercury/o ... ft-housing

Author:  Hounddog [ January 1st, 2020, 3:46 pm ]
Post subject:  Re: TIME TO REVISIT THE 60HP & 40HP....59 CU. IN. 2 STROKE M

Blocks and carbs
They say the 1998 and 1999 40 hp and 60 hp blocks and carbs were different,
To-days replacement parts show the same parts for both.
The carb main jet can be 44, 52 or 60.

Modified 59 cubic inch motors.
The first one I know of is Jeff Dunn's in 2014.
It was able to turn a 12 x 23 at 7000 on a T type V hull.....73 mph
Since then Jeff has built a few for the tiller drag class.
https://www.youtube.com/watch?v=S0DubylQUug

Here is what he found out.
- the larger carb on the 52 cubic inch and the 59 cubic inch 60 hp are good enough for a mod 59
- the porting can be different in blocks , but you can port any of them similar
- the 1998 60 hp block appears to have better STOCK porting.

Hydro Tec has also played with the 59 cubic inch Mercury.
If you want to spend lots of money it is possible to get over 90 hp out of the 59 Mercury.
They have close to 200 compression and run on race fuel.
Problem is they cost more and perform less than a mod 90 yamaha

THE GOOD NEWS IS.....IT IS EASY TO GET 80 hp AT THE PROP.
It runs on pump gas!
You need an early year 60 hp block.
Clean up and match port it to the legal APBA spec.
Install Jeff Dunn 160 compression pistons...LEGAL IN T CLASS
Likely need 60 main jets
Install plastic reeds
Maybe shorten the tuner.
THEY LAST same as a stock one.

Author:  Hounddog [ January 1st, 2020, 5:17 pm ]
Post subject:  Re: TIME TO REVISIT THE 60HP & 40HP....59 CU. IN. 2 STROKE M

CURRENTLY T850 CLASS IS AN OMC 56 CUBIC INCH CLASS.

T850 was for all makes to be competitive.
The mod 56 fishing motor eliminated the 59 Mercury and 70CES yamaha from being competitive.
A boat race class without the other major manufacturers racing limits fan interest....especially with NO Mercury

A simple clarification of the T850 56 OMC rule makes the 59 cubic inch 160 compression Mercury VERY COMPETITIVE.

OMC 56 rule
- can be ported up to SST 60 spec
- 160 lb maximum compression and/or 30.5 cc minimum head volume
- 73D maximum jet size

Author:  sheuninck [ January 1st, 2020, 8:58 pm ]
Post subject:  Re: TIME TO REVISIT THE 60HP & 40HP....59 CU. IN. 2 STROKE M

omc 56 vs mod 59 mercs, 2 heats, New Martinsville, last year.
https://www.facebook.com/APBARacing/vid ... 213704972/

Author:  Hounddog [ January 2nd, 2020, 1:18 pm ]
Post subject:  Re: TIME TO REVISIT THE 60HP & 40HP....59 CU. IN. 2 STROKE M

sheuninck wrote:
omc 56 vs mod 59 mercs, 2 heats, New Martinsville, last year.
https://www.facebook.com/APBARacing/vid ... 213704972/


Mercury is competitive
https://scontent.fybz2-2.fna.fbcdn.net/ ... e=5EACAFC3

https://scontent.fybz2-1.fna.fbcdn.net/ ... e=5E9DE95A

Author:  Hounddog [ January 2nd, 2020, 1:59 pm ]
Post subject:  Re: TIME TO REVISIT THE 60HP & 40HP....59 CU. IN. 2 STROKE M

I revised my first post to add more information about parts.

SO THE GOOD NEWS IS YOU CAN REPAIR THEM NOW FOR LESS MONEY
Short shaft mid sections are available new.??
https://www.boats.net/product/mercury/8 ... ef346f7195

This one will work
It is used on the overseas triple
https://www.boats.net/catalog/mercury/o ... aust-plate
And the same part is used on the North American twin
https://www.boats.net/catalog/mercury/o ... ft-housing
So the newer style mid and gear case is the same as the short shaft twin cylinder. 40 cubic inch.
So you could use two parts motors.....short shaft twin ....and long shaft triple...to assemble a short shaft triple.

Author:  sheuninck [ January 2nd, 2020, 2:18 pm ]
Post subject:  Re: TIME TO REVISIT THE 60HP & 40HP....59 CU. IN. 2 STROKE M

Hounddog wrote:


Yes they are. The Yackos have their rigs working really well. Nice bump at end of this video
https://www.facebook.com/thundercatraci ... 106647868/

Author:  Hounddog [ January 3rd, 2020, 10:25 am ]
Post subject:  Re: TIME TO REVISIT THE 60HP & 40HP....59 CU. IN. 2 STROKE M

I am not going to start another thread, but, I will answer the question here.

RE: late model 49 cubic inch 60 hp Mercury
Is there new style factory trim for a short shaft?


The 15 inch 49 mid has been the same for years. 35, 40,45,50,60,65 and 70 hp all use the same part. The early power trim was the twin outside ram set up. I have seen the late model internal ram trim like the long trim on a 15 inch 4 cylinder 40 hp tiller .
I think it used this swivel bracket.

https://www.boats.net/catalog/mercury/o ... el-bracket

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