Arwen's meanderings

Hi everyone and welcome to my dinghy cruising blog about my John Welsford designed 'navigator' named Arwen. Built over three years, Arwen was launched in August 2007. She is a standing lug yawl 14' 6" in length. This blog records our dinghy cruising voyages together around the coastal waters of SW England.
Arwen has an associated YouTube channel so visit www.YouTube.com/c/plymouthwelshboy to find our most recent cruises and click subscribe.
On this blog you will find posts about dinghy cruising locations, accounts of our voyages, maintenance tips and 'How to's' ranging from rigging standing lug sails and building galley boxes to using 'anchor buddies' and creating 'pilotage notes'. I hope you find something that inspires you to get out on the water in your boat. Drop us a comment and happy sailing.
Steve and Arwen

Friday 8 May 2020

carburettor woes

I am a life log learner, curious, inquisitive and always ready to learn new things. Always was as an education professional and always tried to encourage these qualities in those I taught. It is important to take learning risks. Making mistakes is good learning, so long as you don't repeat make the same type of mistakes. 


So, part of me thinks "It is time to learn how to extract a sheared off bolt in a hole". 
I have the drill bits and the bolt extractors. New bolts have been ordered. 

I was given a whole host of tips from kind, generous people on various Facebook forums which I've outlined below:

"You have inadvertently bottomed the bolt in the hole and it has twisted off. Its not uncommon in a blind threaded hole". 


So I proposed drilling a small hole in the bolt after having gently tapped a centre point with a punch, then inserting a bolt extractor and extracting it carefully. I got this advice back:

"Give it a try but after you have drilled it soak it in CRC6-66 marine spray for a couple of days. Then very gently warm the ally casing before using the bolt extractor. The aly will expand more than the bolt which makes things much easier". 

"File the ragged end as flat as you can, centre punch the middle of it so the drill doesn't drift out to the edges and damage the aly, then very slow drill speed. Left handed drill bits work well, tending to unwind the bolt rather than wind it in further"

"Use easyouts - the size marked on them tends to refer to the best drill size in mm for the pilot hole. the hole needs to be a little deeper than expected for the extractor to bite".

"Could try welding a blob with oxy acetylene on the bolt and unscrewing it with locking pliers whilst it is still hot"

Other suggestions included super gluing the broken bolt and trying that. Or, using a dremell to cut a slot for a screwdriver in the sheared off section and then trying to unscrew it.



What worried me most though was that three people for whom I have huge respect - all started their advice with "take it to a small engineering shop and let them do it" .

I was told that there was a real risk that the drill bit might break off in the sheared off portion and then things would be well and truly stuffed. 



So, a life long learning dilemma. Do I follow my heart and give it a go myself, holding to the principles of its OK to make mistakes as long as you learn from them and learning new skills is important in life.

Or, do I follow my head which says "on this occasion Steve, be sensible, take up the kind offer from a real generous gent, who specialises in this kind of thing and who has offered to do it for you if you send him the offending piece".


This hurts my educational principles but I think we all know the sensible thing to do is go with the latter option. Take the knight in shining armour on white horse rescue package. 

Now, I just have to get the inlet manifold off without doing any further damage.

In future, perhaps I should just pay out the £100 to have the outboard serviced each year!



5 comments:

Wayne Johnson said...

Were both carb bolts the same length? It looks like one of the bolts is a through-hole and the other one (with the now-broken bolt) is a blind hole. Did they use a longer bolt on one side than the other? When doing things like this, try to turn the bolts in with your fingers until the flange is seated. If it stops wanting to turn before it fully seats, don't force it.

Look at the bright side: You are only trying to take off the intake manifold. Exhaust components are much worse (LOTS of heat locks fasteners rather impressively).

This was a mistake that should be easy to avoid in the future. I would take the offer to un-bugger the hole and learn from this.

Honestly, your worst case scenario (assuming you can remove the intake manifold) is to replace the manifold. That is a far cry from an entirely new outboard. If you hadn't done this yourself, you would not have located the misplaced bearing and gotten the very generous out-of-warranty replacement from Tohatsu.

We live, we learn, and we make mistakes. I have heard it said that good judgement comes from experience. Experience often follows bad judgement.

Best regards!
Wayne

steve said...

Words of wisdom Wayne - thank you - yes it was a blind hole. I did finger tighten them in as far as possible and it was literally that last half turn that sheared it. As you say - you don't learn if you don't make mistakes and once made you learn never to do it again :)

Literally the very last turn of a bolt, the very last action on the outboard to be performed this year.......soooooo frustrating. But I have managed to extract the manifold, just, and it is parcelled up and ready to be dispatched.

I took lots of photos of the disassembly - I'm just hoping I can get it all back together again in a fortnight's time!!

Wayne Johnson said...

Steve,

Ouch! So close...

Here's hoping it is smooth sailing from here.

God bless!
Wayne

Bursledon Blogger said...

Steve, take the offered engineering shop help, I've used easy outs and they have/can work but an engineering shop have better equipment and skills it doesn't matter how good you are at diy.

steve said...

thanks wayne.

Hiya Max - already done so - I'm occasionally brave/foolish but I know my limitations as well - I know it would end in disaster. So,the mainfold is off and already in a parcel to be dispatched down south on Monday. I'm just hoping I can reassemble everything when it arrives back :)