Big end bearing

[SimonStDavids]

Just starting to think about the winter months and the things that need to be done for next year and thinking about something the outboard servicing place said last year about the big end bearing. Namely that it was starting to make a bit of a noise!

At the time I couldn't hear it, but after the seasons use I am sure I can or at least I am paranoid enough to think I can

At the time I asked how much to replace the bearing and although he didn't give me price he said it would probably cost a fair bit as it quite a tricky job! And a used powerhead would probably be a cheaper option. The engine is a mariner Yamaha 40 6e9. Engine is neither young nor pretty but otherwise seems ok (famous last words

Option one- new powerhead, seen one on fleabag for £225. Is it simply a case if in bolting one and bolting on the new one? Or in other words can a novice with some spanners do it?

Option two- new bearing or complete crankshaft, no idea on price and I am guessing out of my skill set.

Option three- new engine, saw a loverly yam 50 ptt go for 1500 recently, but I guess most 2 strokes are also getting on in years now!

What do people think would be the best way to go?

[Sandy]

I have a complete power head available still. It's pretty straight forward to refit if you are removing one.

http://www.rib.net/forum/f10/yamaha-...der-57720.html

[Locozodiac]

To change the big end bearing located on crank's shaft extreme you need to disassemble the whole crank case apart, that can be a costly time demanding work, could take advantage to change all of crank's shaft main bearings too for engine to work even.

Happy Boating

[9D280]

The other option could be to get someone to reassemble the crank for you- dropping the assembly in is reasonably easy if you have a clean, clear work space.

Can also replace rings, gaskets etc and clean out the cooling passages while its in pieces...

[SimonStDavids]

Thanks Sandy, but I am not sure that powerhead would fit under my cowling, although 10 more horses would be good

Are there many places that reasemble the crank shafts? I quite like the idea of cleaning out the inside a bit as long as i don't manage to wreck it!

[9D280]

I found a place up here. Bound to be somewhere round your neck of the woods.

I was recommended a place by a friend who used to kill car engines They were doing the re-bore of the cyls and volunteered to reassemble it with the new +0.30" pistons.

A crank is a crank if you are in that line of work.


I can give you a couple of names, but both up in Sunny Scotland.