Reply
 
Thread Tools Search this Thread
 
Old 22 March 2018, 10:23   #1
Member
 
Country: UK - England
Town: Bournemouth
Make: Avon
Length: 3m +
Engine: Merc 25hp 2stroke
Join Date: Nov 2014
Posts: 107
Lower unit bolts

Maybe a stupid question so apologies! however are the bolts holding the lower unit on just straightforward marine grade stainless?

My Towatsoo lower unit was held on with x4 metric sized bolt heads and x2 imperial (weird) and all were showing signs of being rounded by previous attempts (not me!) to remove so I was planning to replace them all with A4 grade stainless bolts but just wanted to check in case? TIA
__________________
mattwarner is offline   Reply With Quote
Old 22 March 2018, 12:16   #2
Member
 
Country: UK - England
Town: Retford
Boat name: Spy-sea-one
Make: Excel 435
Length: 4m +
Engine: Suzuki Outboard/25/4
Join Date: Oct 2011
Posts: 7,441
RIBase
replace with the correct bolts Matt, sounds like someones been using open ended spanners or a crap make hence different bolts originals damaged too much. problem is imperial might have damaged the thread on the metric insert but that can be replaced.
__________________
jeffstevens763@g is offline   Reply With Quote
Old 22 March 2018, 12:51   #3
Member
 
Country: UK - Scotland
Town: north ayrshire
Boat name: charlie girl
Make: S/R5.4/regal3760
Length: 10m +
Engine: Suzukidf70 2x6lp 315
Join Date: Jul 2009
Posts: 3,716
Possibly a different hardness to a standard a4 or a2 stainless bolt there pretty soft so its possible the manufacturers used a special to hold a critical component
__________________
beamishken is offline   Reply With Quote
Old 22 March 2018, 20:56   #4
Member
 
Country: UK - England
Town: Cullompton Devon
Boat name: SeaKnight
Make: bayliner Capri 20'
Length: 6m +
Engine: Yam V4 130hp
Join Date: Oct 2011
Posts: 359
hi guys ive just brought a4 marine stainless steel bolts, would you recommend to use another type ? i only got them as i thought they would be the best for marine environment
__________________
arkamelis is offline   Reply With Quote
Old 22 March 2018, 23:31   #5
Member
 
Country: UK - Scotland
Town: north ayrshire
Boat name: charlie girl
Make: S/R5.4/regal3760
Length: 10m +
Engine: Suzukidf70 2x6lp 315
Join Date: Jul 2009
Posts: 3,716
Check the hardness marks on the head of the origionals and get the same grade if you can.
Stainless bolts are often much weaker than a high tensile carbon steel bolt
__________________
beamishken is offline   Reply With Quote
Old 23 March 2018, 09:46   #6
Member
 
Country: UK - England
Town: Bournemouth
Make: Avon
Length: 3m +
Engine: Merc 25hp 2stroke
Join Date: Nov 2014
Posts: 107
for a lower unit surely they cant be made from anything over than stainless?
__________________
mattwarner is offline   Reply With Quote
Old 23 March 2018, 10:38   #7
Member
 
Country: UK - Scotland
Town: north ayrshire
Boat name: charlie girl
Make: S/R5.4/regal3760
Length: 10m +
Engine: Suzukidf70 2x6lp 315
Join Date: Jul 2009
Posts: 3,716
Quote:
Originally Posted by mattwarner View Post
for a lower unit surely they cant be made from anything over than stainless?
Different manufacturers use different methods of corrosion resistance. Yamaha bolts are fully magnetic indicating high tensile steel,suzuki and mercury are none magnetic suggesting stainless but there are differing grades of stainless to achieve different hardnesses, standard 316 or 304 are both soft in comparison to hts
__________________
beamishken 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




All times are GMT. The time now is 08:45.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.