Crack and damage in the crank case

toler85 · L Plate Warrior Joined: 28 May 2017 Karma :

https://i.imgur.com/mwwMrG8.jpg
https://i.imgur.com/YaoZ6zO.jpg
https://i.imgur.com/t0G8IUD.jpg

What should I do?

V2 · Nearly there... Joined: 06 Feb 2006 Karma :

a) Leave it be
b) Get it welded up
c) Buy new engine

Thumbs Up

Mentacycle · Borekit Bruiser Joined: 09 May 2017 Karma :

d) replace castings

Polarbear · Super Spammer Joined: 24 Feb 2007 Karma :

Is this historical and you just noticed it or have you just dropped the bike?

If it's historical and not leaking oil I'd just leave it. If it's new, I'd ride it and see how bad the oil leak is.

Edit - After saying that, what's going on in the second picture under the insulation taped cable. Is that broken crankcase as well?
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Triumph Trophy Launch Edition

Pete. · Super Spammer Joined: 22 Aug 2006 Karma :

I'd paint over that and forget about it.
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a.k.a 'Geri'

132.9mph off and walked away. Gear is good, gear is good, gear is very very good Very Happy

Chris45 · Nitrous Nuisance Joined: 23 Oct 2016 Karma :

MCN · Super Spammer Joined: 22 Jul 2015 Karma :

It looks like the long crack is only the weaker side of the big long bolt hole.
The force that blootered the chunk out of the other piece was possibly responsible for the big long crack.

Ride on.
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Disclaimer: The comments above may be predicted text and not necessarily the opinion of MCN.

kramdra · World Chat Champion Joined: 28 Oct 2010 Karma :

Its not on an engine mount and its on the top of engine, however it is right next to the top end oil feed bolt.

As proximity to the front sprocket, Im assuming a chain has snapped in the past and taken the sprocket cover with it, hence the bodge and tape.

Paulf · Nova Slayer Joined: 24 Jan 2017 Karma :

Looking at the photos things will get worse due to engine vibration. I am not sure which honda engine this is going on the name on the crankcase. Choices are ride it and monitor the cracks on a daily basis or change the engine. To repair will mean mechanically gouging out all signs of cracks then tig welding and perhaps some machining afterwards. And if you have no access to the equipment it can work out expensive. You cannot just weld over the cracks same as papering over cracks does nothing. Also some alloys requires post heat treatment to relieve stress of welding. Which will require stripping the engine. Please note crack propagation (growing) is not linear in alloys and can grow at alarming rates if the condition are right. My experience comes from being involved in the repairing aluminium bodied railway vehicles that have suffered stress cracking.
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Past bikes simsom mofa 1s, suzuki hustler 250 (£35 in 1973), suzuki ts125k, mz150, yamaha yb 100, honda pc50, honda vision 50, all 2 stroke - then cars - honda pcx 125 (sold) own honda fes 125 and Mrs 125 spares or repairs. Started 1972 all accidents walked away no insurAnce claims

Pete. · Super Spammer Joined: 22 Aug 2006 Karma :

The damage lower down is obviously the result of a bunched chain and it's possible that the long crack is related to that but equally possible its from casting shrinkage. It's certainly no reason to cry doom, gloom, disaster and going by the state of the gear lever I'd say the bike isn't in the sort of condition that warrants spending out on new cases or engine anyway.

If it's leaking oil badly then you might want to do something but if it's just getting a bit of oil mist on the dirt leave it alone and top up as necessary. It's not going to explode on you.
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a.k.a 'Geri'

132.9mph off and walked away. Gear is good, gear is good, gear is very very good Very Happy

Paulf · Nova Slayer Joined: 24 Jan 2017 Karma :

Having reviewed the photos again I tend to side with last post Pete it looks old damage especially near the sprocket cover. One old idea to stop the crack growing is to drill a small diameter hole at end of crack. But I would ride it and watch what happens. If is gets worse drill end and put metalset on to keep it oil tight.
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Past bikes simsom mofa 1s, suzuki hustler 250 (£35 in 1973), suzuki ts125k, mz150, yamaha yb 100, honda pc50, honda vision 50, all 2 stroke - then cars - honda pcx 125 (sold) own honda fes 125 and Mrs 125 spares or repairs. Started 1972 all accidents walked away no insurAnce claims

Chris45 · Nitrous Nuisance Joined: 23 Oct 2016 Karma :

MCN · Super Spammer Joined: 22 Jul 2015 Karma :

The crack is most probably only the outside of the 'bolt hole'.
The inside of the 'bolt hole' will obviously still be hail or the pressure from that long bolt would split the case open.

De-grease it and spray it Lada Stratus Silver.

Get on with your life. Smile

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Disclaimer: The comments above may be predicted text and not necessarily the opinion of MCN.