Reply
 
Thread Tools Search this Thread
 
Old 07 July 2013, 13:40   #11
Member
 
Country: UK - England
Town: Sheffield
Boat name: Touch Bottom
Make: Avon
Length: 4m +
Engine: 50 hp Merc Power t&t
Join Date: Jul 2008
Posts: 239
Not had much success with this 4hp Yamaha, I suspect there is more crud in the water jacket, but not having a manual I don't know how to get to the water galleries around the cylinder. Does any one know if this is a blind bore? I could maybe take the end plate off to see if I can unclog it.
__________________

__________________
Mercury is offline   Reply With Quote
Old 10 July 2013, 16:47   #12
Member
 
Locozodiac's Avatar
 
Country: Other
Town: Lima-Peru
Boat name: Nautile
Make: Sea Rider Boats
Length: 4m +
Engine: Tohatsu 18 /30 HP
Join Date: Sep 2007
Posts: 1,706
Mercury.

If the crankcase's back has several bolts securing the cylinder head, it's completely removable, just remove all bolts, with a rubber mallet hit upper cyl head. Most times stays near solded between them and needs some vigorous hits to become dislodged.

Once cyl head is removed rub mechanically with a small screwdriver, Chineese wooden stick all crankcase and head waterways of salt layers, salt crusts, whatever is finally found obstructing inside water flow. Will ned a new head gasket, torque to specs when assembling back.

Don't need a manual, just take pictures while disassembling parts, once done with work, put them back together.
__________________

__________________
Locozodiac is offline   Reply With Quote
Old 10 July 2013, 17:49   #13
Member
 
Country: UK - Scotland
Town: wormit
Boat name: lots of them
Make: various
Length: no boat
Engine: all types
Join Date: Dec 2004
Posts: 388
Grip the drive shaft support tube in a vice and start the engine and run it with your finger on the block until it hurts. Remove the 4 bolts on flat plate nearest the spark plug, this is the head cover, your engine has a blind bore. Start it again to get more heat into the block. Remove the plate with the 8 bolts on the opposite side from the spark plug. You will find the thermostat in there but it's the small slot in the sandwich plate that will be choked with a bit of weed. If its a 6 bolt cover its an early model and there will be no thermostat. When you order the gaskets make sure you order an inner and an outer as they are not the same.
__________________
Davie is offline   Reply With Quote
Old 11 July 2013, 14:20   #14
Member
 
Country: UK - England
Town: Sheffield
Boat name: Touch Bottom
Make: Avon
Length: 4m +
Engine: 50 hp Merc Power t&t
Join Date: Jul 2008
Posts: 239
Quote:
Originally Posted by Davie View Post
Grip the drive shaft support tube in a vice and start the engine and run it with your finger on the block until it hurts. Remove the 4 bolts on flat plate nearest the spark plug, this is the head cover, your engine has a blind bore. Start it again to get more heat into the block. Remove the plate with the 8 bolts on the opposite side from the spark plug. You will find the thermostat in there but it's the small slot in the sandwich plate that will be choked with a bit of weed. If its a 6 bolt cover its an early model and there will be no thermostat. When you order the gaskets make sure you order an inner and an outer as they are not the same.
Many thanks for the help. I shall have a go first chance I get, where do I get the gaskets from?
__________________
Mercury is offline   Reply With Quote
Old 11 July 2013, 15:46   #15
Member
 
Country: UK - England
Town: Sheffield
Boat name: Touch Bottom
Make: Avon
Length: 4m +
Engine: 50 hp Merc Power t&t
Join Date: Jul 2008
Posts: 239
Just had a look, It's a 4 AC. Serial No. 6EO S 054298.
There are 4 bolts on the end, & 9 bolts on the side. I dont know what year it is, maybe someone on here will know.
__________________

__________________
Mercury is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off





Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -5. The time now is 22:49.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.