Snapped bolts on ali outboard block

[slimtim]

An update...

I have not done anything on the engine for a few days because I have encountered trailer brake issues

Anyway, I need to take the block off which doesn't look like too bad a job. I have already successfully loosened the block bolts so I know they'll come out.

At the moment I am not holding out much hope of saving the engine so am seriously considering buying another one (90hp) and then selling all the tohatsu parts which I think I could get decent money for (maybe even nearly as much as selling the engine complete, just a lot more hassle!). Only thing is, I'm jobless which means I can't justify outlay for another engine until I secure a job

[codprawn]

I remember some people laughing at me when I said it wasn't good engineering practice to put steel bolts straight into alloy without hardened steel inserts. What the hell were these engine makers thinking - especially in a marine environment???

[Jono]

Originally Posted by codprawn

I remember some people laughing at me when I said it wasn't good engineering practice to put steel bolts straight into alloy without hardened steel inserts. What the hell were these engine makers thinking - especially in a marine environment???

Your memory's hazier than mine.... what they said was "cobblers" to your statement that "..Ali was too weak to take a thread and they used hardened steel inserts"...

[9D280]

Originally Posted by Downhilldai

Provided the lower unit bolts come out ok.......

Good call, but realistically the impeller is likely to have been changed more recently than the exhaust plate was removed, making it slightly more likely to come apart! - My old yam the gearbox almost fell off (figureitively, I hasten to add!), and you know what happened "up top".....

Other way of looking at it, if you have proved you can get the head off easily & in a proper workshop, the dirilling accuracy you can get with a bench drill (as opposed to hand drilling while you lean on the transom with a Black & Decker) may make a rebuild feasible again. Have a trawl round t'internet- somewhere out there will be a pic of a stripped block to show you how much margin for error you have. Had mine not turned to shortbread (previous owner(s) not replacing anodes while it lived on a mooring), the helicoils would have worked a treat.

[adrian c]

Hi Slimtim

Had similar problems with my ageing Yamaha 90 last year but she back running with a new crankshaft and piston, if I can be of any assistance as I see you are also on the iow please pm me (two heads are better than one )

regards
Adrian

[Nasher]

Originally Posted by slimtim

At the moment I am not holding out much hope of saving the engine so am seriously considering buying another one (90hp)

Come on now Tim, what you actually mean to say is that you WANT a 90HP engine to make the boat go faster, and you've found a half decent excuse to justify it.

The thing is you've only yourself to fool, where as I've had to use this type of excuse on Mrs Nasher so many times when I've wanted to buy something that just can't be justified with anything other than 'I want it'.

I remember for example, all of a sudden the gearbox really was about to give up the ghost in my Volvo. Strangely this problem occured on the same day that I test drove the 280BHP Subaru Legacy GT Estate I ended up buying to replace it

Nasher.

[chris123]

Originally Posted by slimtim

At the moment I am not holding out much hope of saving the engine so am seriously considering buying another one (90hp)

Just because of a few broken bolts?

If you want an excuse to buy a bigger engine fair enough, but seriously, (at the risk of repating myself from 6 pages ago) take it to a decent machine shop and they will sort it for peanuts (the bolt with the eazi-out in it will need spark erosion or similar so will cost a bit more).

Cheers

Chris

[slimtim]

you got that about right nasher

You did however mis-quote my smiley face effectively making out that I am sad at the prospect of an extra 20hp and 40+knot top speed whereas the truth is that I am sad at the fact I don't have a job yet and so can't justify said outlay

That may well change in the next 2 days though

[JSP]

Originally Posted by Nasher

Come on now Tim, what you actually mean to say is that you WANT a 90HP engine to make the boat go faster, and you've found a half decent excuse to justify it.

The thing is you've only yourself to fool, where as I've had to use this type of excuse on Mrs Nasher so many times when I've wanted to buy something that just can't be justified with anything other than 'I want it'.

I remember for example, all of a sudden the gearbox really was about to give up the ghost in my Volvo. Strangely this problem occured on the same day that I test drove the 280BHP Subaru Legacy GT Estate I ended up buying to replace it

Nasher.

You sound like me.

[slimtim]

hey chris, I am still going to give it a go and as a result of your advice I have found out about a good machine shop over here that may be able to help if I don't have any success.

I don't know how much a machine shop would charge though, its got to be a few hours work and I don't think it would be worth spending too much on an engine of this age.

cheers,

Tim

[Bigmuz7]

Originally Posted by chris123

they will sort it for peanuts (the bolt with the eazi-out in it will need spark erosion or similar so will cost a bit more).

On this topic I researched this as an idea way back in the early posts, and realised after some research that there are several different types of spark erosion, but did wonder if this was a feasible method ? but since the bolts are so small I never followed it up .. so .. is it possible ? Cos I thought if the metals are dis-similar, maybe it wouldnt work?

[Downhilldai]

Originally Posted by slimtim

.. I don't think it would be worth spending too much on an engine of this age.

A 1996 70hp motor would be worth putting right for the sake of a couple of hours labour (even a Twatsoo), provided it's otherwise in decent order and doesn't need any more spending on it.

[Jono]

Originally Posted by slimtim

hey chris, I am still going to give it a go and as a result of your advice I have found out about a good machine shop over here that may be able to help if I don't have any success.
Tim

Might I suggest that you get it to them now before your do anything else that might make it harder. .therefore more expensive.. for them to sort out for you?

[bedajim]

Originally Posted by Jono

Might I suggest that you get it to them now before your do anything else that might make it harder. .therefore more expensive.. for them to sort out for you?

What and kill this thread I think it could be padded to another 10 pages maybe even include an angle grinder to trim the bolts and re fix with Sikaflex

[Dirk Diggler]

Originally Posted by Bigmuz7

after some research that there are several different types of spark erosion,

Multi Spark in Poole will do it for you, ask for Dave.

[Downhilldai]

Did you sort this out, Tim?

[slimtim]

yes!

I disassembled everything which went well. I then drove around the isle of wight trying to find someone who would attempt to sort it out for me.

Lots of machine shops wouldn't touch it, were a very high price (£25/bolt) or wanted me to completely disassemble the powerhead (I had the flywheel and head still on there). Spark erosion was either too expensive or it wouldn't fit in the tank.

Eventually I came across Lake Precision Engineering (not in Lake, in Fishbourne!) who have drilled and helicoiled it for only £120. I have not seen it yet but apparently they have done a really good job. I would highly recommend these people as they were the only ones that were keen to do it at a reasonable price and were willing to cope with the powerhead being only semi-disassembled. I will be using them again I think as they also do stainless fabrication.

Hoping to put it all back together today so I can get out on the water this weekend!

(oh, by the way, tried to use a blow torch and mole grips but had no success, the bolts were well stuck in there.)

[Downhilldai]

Good news.