Mariner and Tohatsu 2-stroke 5hp parts interchangeability, please help

[joeokros]

Hi, New to this forum but have been lurking and know there are some very knowledgeable people here. I have a 1999 Mariner MA5S 5hp outboard that I need to change the crankshaft bearings on. I would buy the parts direct if I could, but being in New Zealand the best priced online shop cant send me Mercury/Mariner spares as I am not in the USA.

The motor appears to be identical to the Tohatsu 5hp motor and ********** has no problem sending me Tohatsu spares.

My question, Are the crank bearings on a 1999 2-stroke 5hp Tohatsu the same as the same vintage Mariner?

Unfortunately I cant find an online Tohatsu/Mariner/Mercury cross reference parts lookup

 

[carholme]

Re: Mariner and Tohatsu 2-stroke 5hp parts interchangeability, please help

Crowley has the bearings and I am pretty sure they ship overseas and if you really need bearings, $22 per unit is not that bad.

Do you have the bearings off right now? If so, what are the numbers you can see etched on the edges of the races?

Gerry

 

[Sea Rider]

Re: Mariner and Tohatsu 2-stroke 5hp parts interchangeability, please help

Mercury codes does not match Tohatsu/Mariner ones, are completely different.

Tohatsu/Nissan codes for M4C-M5B-M5BS series, assume MA5S is prob same just older. Better check.

Ball Bearing 6204 : 960336204M (x 2)
Oil Seal : 369001220M (x2)

Will need to replace both upper and lower bearings along upper and lower oil seals, just in case and do a one time job..

Happy Boating

 

[joeokros]

Re: Mariner and Tohatsu 2-stroke 5hp parts interchangeability, please help

Crowley has the bearings and I am pretty sure they ship overseas and if you really need bearings, $22 per unit is not that bad.

Do you have the bearings off right now? If so, what are the numbers you can see etched on the edges of the races?

Gerry

Thanks Gerry, I can get the bearings in New Zealand but they cost $51 each!!!. The numbers are Nachi (presume its the maker) and 5204554. Dimensions approx - at crank 20mm diameter, outer diameter 50mm and width 14mm. It has eight balls in the races. The supplier that I normally use online is boats and on the net . They wont supply Mercury/Mariner parts to New Zealand, but they do supply Tohatsu, -and the Tohatsu parts are much cheaper. ie this particular bearing is only about $7.10 for the pre 2002 M5BS part number 96033-6204M. For the post 2002 motor the part number is 9603-3-6204, but still only $7.10.

The head gasket also looks identical for way cheaper.

 

[joeokros]

Re: Mariner and Tohatsu 2-stroke 5hp parts interchangeability, please help

Crowley has the bearings and I am pretty sure they ship overseas and if you really need bearings, $22 per unit is not that bad.

Do you have the bearings off right now? If so, what are the numbers you can see etched on the edges of the races?

Gerry

The numbers are Nachi (presume its the maker) and 6204554. Dimensions approx - at crank 20mm diameter, outer diameter 47mm and width 14mm. It has eight balls in the races.

 

[carholme]

Re: Mariner and Tohatsu 2-stroke 5hp parts interchangeability, please help

That is just a standard 6204 bearing.

This is a Nachi:

http://www.vxb.com/page/bearings/PROD/SealedBearings/Kit9705

However, if you have a bearing supplier where you live, take your bearing in and ask for an SKF 6204:

http://www.skf.com/skf/productcatal...ableName=1_1_1&presentationType=3&startnum=12

or a Torrington:

http://www.srg-bearings.com/TORRINGTON/TORRINGTON6204/

Aside from being inexpensive, I am sure he will tell you that they are the same bearing.

Gerry

 

[joeokros]

Re: Mariner and Tohatsu 2-stroke 5hp parts interchangeability, please help

Thanks Gerry,
I've ordered the Tohatsu parts, figured at $7 a bearing as long as the dimensions are the same I cant go to far wrong. Just 2 more questions please. I bought the motor as parts in a box, so even though I have done minor work on one of these before, - electrical and changing heads, I am no expert.

1. The bearings that are with it have one hole in the outer race, I presume this hole must be oriented to the inside of the crankcase for lubrication.?
2. The cranckase halves just fit together with loctite 518 and no gasket? No gasket apparent in the cardboard box of bits it all came in.

 

[carholme]

Re: Mariner and Tohatsu 2-stroke 5hp parts interchangeability, please help

Well that changes the standard 6204 bearing theory. If the bearing has a manufactured hole in the outer race, it will be p/n specific. I doubt the hole in the outer race is for lubrication unless you have a way to pin the bearing to prevent the outer race from turning. Otherwise, if the bearing outer race spun, you would lose lubrication and things would stop pretty quickly.

Is there just the one hole in the outer race? If so, do you see a matching hole in the bearing bore in the block? If so, is it just a drilled hole to accept a dowel pin? If this is the case, you should have two matching dowel pins in your parts box and these will be alignment pins to prevent the outer race from spinning in the block.

What is your engine s/n?

Gerry

 

[joeokros]

Re: Mariner and Tohatsu 2-stroke 5hp parts interchangeability, please help

OG712022,-There is no matching hole in the block but the hole is offcentre. Perhaps that has some significance?

 

[carholme]

Re: Mariner and Tohatsu 2-stroke 5hp parts interchangeability, please help

Don't understand what you mean by the hole being off centre.

I wanted the s/n to get the parts listing for your engine:

http://www.crowleymarine.com/mercury-outboard/4603.cfm

If you look under Cylinder Block/Crankshaft/Piston, item 21, you will see the pin installed in the bearing.

Here is a better view of the bearing from ishop:

http://www.ishopmarine.com/partsGuide/0/1/1/47/supplier-050-025-MM/MM/75_4631_5004

Click on the view application list and you will see the bearing.

Gerry

 

[joeokros]

Re: Mariner and Tohatsu 2-stroke 5hp parts interchangeability, please help

Thanks Gerry,
By offcentre I meant that if you look at the bearing side on, its 14mm wide - the hole is not located at the 7mm mark (which would be the centre), but more towards the side.

The Tohatsu ones I ordered come from this schematic, http://www.**********/parts/search/Tohatsu/Outboard/2003/M5BS/PISTON%20%26%20CRANK%20SHAFT/parts.html. They seem to have that pin as well, so it should be OK. I cant find any pins in the box, so hopefully they come with the bearing.-

Once again thank you for your help, I'll probably be back here once the parts arrive and I take a look at them. Right now there is no rush as I'm soaking the head in PB Blaster as the piston is seized. There is no rust or scoring in the cylinder bore, so I'm hopeful that patience will prevail with some judicious tapping.

 

[carholme]

Re: Mariner and Tohatsu 2-stroke 5hp parts interchangeability, please help

Good luck with it and keep us informed.

Gerry

 

[joeokros]

Re: Mariner and Tohatsu 2-stroke 5hp parts interchangeability, please help

OK,--so my parts have arrived and I can say definitively that a 1999 Mariner uses the same parts as a same vintage Tohatsu, -the oil seals and crank bearings are identical down to the same manufacturer with their numbers on it. The holes in the bearings are for locating pins that fit in the crankcase. The piston did not come out undamaged so I bought a replacement from a vendor that ships out of Shanghai, including rings came to $25.

The Tohatsu parts are less than half the cost of the Mercury/Mariner parts from that website I am not allowed to mention. For example the crankshaft bearings came in at under $8 !!!!!!. In NZ those same bearings cost NZ$65 (about US$50).

Will update this thread once I have installed everything, but I am a bit concerned that the crank looks slightly twisted,--by eye only,-but I guess we will see when I start assembling. I have ordered a new needle bearing for the small end, but unfortunately do not have access to the tools that would make splitting the crank viable, so will leave that intact and pray the big end bearing is OK,- It spins smoothly and without noise. I know its a risk, but engineering work in NZ would make splitting the crank a non-economical proposition.

So far I have $243 in this motor, includes purchase of motor and new gaskets (including head-gasket), piston, rings, bearings, oil seals. I still need to spend on Loctite 518 master gasket maker and change the gearoil. With a bit of luck I should have a pretty close to new outboard for approx $250.

 

[joeokros]

Re: Mariner and Tohatsu 2-stroke 5hp parts interchangeability, please help

Well, everything together , breaking in--I've got 4 hrs on her now and sounding good.