O/B motors 2 stroke vs. 4 cycle - Page 2 - SailNet Community

   Search Sailnet:

 forums  store  


Quick Menu
Forums           
Articles          
Galleries        
Chat  
Boat Reviews  
Classifieds     
Search SailNet 
Boat Search (new)

Shop the
SailNet Store
Anchor Locker
Boatbuilding & Repair
Charts
Clothing
Electrical
Electronics
Engine
Hatches and Portlights
Interior And Galley
Maintenance
Marine Electronics
Navigation
Other Items
Plumbing and Pumps
Rigging
Safety
Sailing Hardware
Trailer & Watersports
Clearance Items

Advertise Here






Go Back   SailNet Community > On Board > Gear & Maintenance
 Not a Member? 
  #11  
Old 09-09-2006
Junior Member
 
Join Date: Mar 2006
Location: Avalon Catalina
Posts: 15
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
Nathan West is on a distinguished road
Just a quick note. All small Mercury outboards (25hp or less) are made by Tohatsu. The only differance is the decals, you will notice Tohatsu's are now painted Mercury black, and of course the price, Mercury's are about $200-$400 more.
Reply With Quote Quick reply to this message Share with Facebook
  #12  
Old 09-09-2006
Shack's Avatar
Senior Member
 
Join Date: Sep 2006
Location: Annapolis
Posts: 199
Thanks: 6
Thanked 0 Times in 0 Posts
Rep Power: 9
Shack is on a distinguished road
Quote:
Originally Posted by Nathan West
Just a quick note. All small Mercury outboards (25hp or less) are made by Tohatsu. The only differance is the decals, you will notice Tohatsu's are now painted Mercury black, and of course the price, Mercury's are about $200-$400 more.
Great! Then I should be able to an impellar for my water pump from a Mecrucy parts catalog?
Reply With Quote Quick reply to this message Share with Facebook
  #13  
Old 09-09-2006
Junior Member
 
Join Date: Mar 2006
Location: Avalon Catalina
Posts: 15
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
Nathan West is on a distinguished road
Sorry Shack, I should qualify -don't you hate when they do that- I know that all the small Merc 4 stroke start about 2000 were made made by Tohatsu. The 2 strokes I'm unsure about. also models before 2000 I don't know about I'll try to get more info
Reply With Quote Quick reply to this message Share with Facebook
  #14  
Old 09-10-2006
can't re member
 
Join Date: Aug 2006
Posts: 318
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 9
yotphix is on a distinguished road
If you check out Yamaha's site you will notice that only the four stroke is available in long shaft. The weight difference is 25% or 79lbs for the two stroke vs. 99lbs for the four stroke. The other interesting difference is that the alternator on the four stroke outputs 10a vs. the two's 6a. As to why a four stroke weighs more, one good clue is that the displacement of a four (9.9) is 19.7ci while the two (same hp) is 15.0ci.
Reply With Quote Quick reply to this message Share with Facebook
  #15  
Old 09-10-2006
Shack's Avatar
Senior Member
 
Join Date: Sep 2006
Location: Annapolis
Posts: 199
Thanks: 6
Thanked 0 Times in 0 Posts
Rep Power: 9
Shack is on a distinguished road
Nathan,
If you have any sources, I am all ears.

But I'm still on course to update/upgrade my o/b to more a contemporary model that is more maint friendly (i.e. resources).

You know - I'd love for a o/b repairman to chime in and tell what the part compatability is between the two for 2007 models. If the sticker on the outside is the whole difference, then its an easy decision.

But I suspect the marketing guys got their fingers in the stew and ensured that there was the odd sized codder pin or a bolt that only produced in northeast Thailand that makes up the difference between the two.


Last edited by Shack; 09-10-2006 at 02:03 PM.
Reply With Quote Quick reply to this message Share with Facebook
  #16  
Old 09-10-2006
Canibul's Avatar
Banned
 
Join Date: Aug 2006
Location: Land of MakeDoo.
Posts: 107
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
Canibul is on a distinguished road
having just rebuilt my first two-stroke outboard I gotta say I am not sure why anyone would declare a 2 stroke "on its last legs". (unless you just need a good reason to buy a new motor). 2 strokes are simple, and as long as the reason one isnt running isnt because someone ran it without oil and ruined it totally, everything on it is pretty much easy to replace. No valve train, cam, etc. Four strokes are definitely quieter, and more efficient in terms of miles per gallon. Way more complex and costly to fix, a lot more parts. Less horsepower for the displacement. heavier. Takes more moving parts to operate them valves. 2 strokes just have about three moving parts, pistons, rods, and crankshaft. Reed valves last forever and are easy to replace. No crankcase oil to deal with. I still like the 2 strokes. simplicity is important.
Reply With Quote Quick reply to this message Share with Facebook
  #17  
Old 09-10-2006
Member
 
Join Date: Aug 2006
Posts: 34
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
catalyst27 is on a distinguished road
as this motor was with the boat when it was brought i can not confirmed or deny any abuse to the engine the motor part you are correct it is the cheapest item to rebuild but the upper and lower part of the engine are the more expensive items to repair and replace the transmission needs alot of attention the lower housing is cracked and the zincs have been gone for a long time the mounting bracket is broken so the engine will not lock down that assembly is roughly 400 bucks alone the motor is a 1976 model so parts available is also a issue the mechinic and i spent about an hour on the internet before we found about 35% of the parts needed and as he said the parts issue is only going to get worse as time goes on... the engine parts and rebuild is roughly about 450 bucks as the starter and flywheel will need to be replaced the starter is kaput and the flywheel is missing teeth and eroded badly the pump we have assumed also needs to be replaced as well as low water flow from the pump (we were be both impressed that the engine would even run) no amps from alt. so it may have to be rebuilt...
so considering everything i believe that a replacement engine would be better in order than repairing this one but maybe i am wrong
Reply With Quote Quick reply to this message Share with Facebook
  #18  
Old 09-10-2006
sailingdog's Avatar
Telstar 28
 
Join Date: Mar 2006
Location: New England
Posts: 43,290
Thanks: 0
Thanked 14 Times in 12 Posts
Rep Power: 13
sailingdog is just really nice sailingdog is just really nice sailingdog is just really nice sailingdog is just really nice sailingdog is just really nice
Catalyst27-

I would definitely upgrade to a new OB motor if I were in your shoes. Investing more in the old one is probably throwing good money after bad.
__________________
Sailingdog

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Telstar 28
New England

You know what the first rule of sailing is? ...Love. You can learn all the math in the 'verse, but you take
a boat to the sea you don't love, she'll shake you off just as sure as the turning of the worlds. Love keeps
her going when she oughta fall down, tells you she's hurting 'fore she keens. Makes her a home.

óCpt. Mal Reynolds, Serenity (edited)

If you're new to the Sailnet Forums... please read this
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
.

StillóDON'T READ THAT POST AGAIN.
Reply With Quote Quick reply to this message Share with Facebook
  #19  
Old 09-10-2006
Member
 
Join Date: Aug 2006
Posts: 34
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
catalyst27 is on a distinguished road
yes sir my thoughts also Thanks to all of those who gave an opinion
Reply With Quote Quick reply to this message Share with Facebook
  #20  
Old 09-10-2006
Shack's Avatar
Senior Member
 
Join Date: Sep 2006
Location: Annapolis
Posts: 199
Thanks: 6
Thanked 0 Times in 0 Posts
Rep Power: 9
Shack is on a distinguished road
My 5hp o/b is doesn't have cooling water running through it!

I inhereted it with the boat recently.

I've flushed it.
A mech looked at it twice (only charged me once).
Impelar in the books does not fit the motor. (Tohatsu 1997)
Kind-of a mystery right now on how to get the water pump fixed.

Gear shifter handle is broke off at the base, and motor now requires a body twist and a "trick" to get it to shift into F-N-R.

Handle for strbd mounting bolt is broke - needs "vice-gripe-adapter" mechansim. This upgrade also useful on broker gear shifter!

Starts real well, though! Water pump issue has me befuddled. Seems like all I need is little rubber impellar. I guess I am adding up problems in order to make an excuse for getting new motor.

. . . but its alot of work trying to leave the Marina under sail. Tacking out a 100' wide channel against a stong wind . . . those darn pilings keep poppi
ng up everywhere!!
Reply With Quote Quick reply to this message Share with Facebook
Reply

Quick Reply
Message:
Options

By choosing to post the reply above you agree to the rules you agreed to when joining Sailnet.
Click Here to view those rules.

Register Now

In order to be able to post messages on the SailNet Community forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
Please note: After entering 3 characters a list of Usernames already in use will appear and the list will disappear once a valid Username is entered.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

 
Posting Rules
You may post new threads
You may post replies
You may post attachments
You may edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On


Similar Threads
Thread Thread Starter Forum Replies Last Post
1981 Honda 9.9, 4 stroke o/b, Idle problem randj65 Gear & Maintenance 4 06-19-2002 11:59 AM


All times are GMT -4. The time now is 12:58 PM.

Add to My Yahoo!         
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2015, vBulletin Solutions, Inc.
SEO by vBSEO 3.6.1
(c) Marine.com LLC 2000-2012

The SailNet.com store is owned and operated by a company independent of the SailNet.com forum. You are now leaving the SailNet forum. Click OK to continue or Cancel to return to the SailNet forum.