Stuck/Seized Mag Housing... Any Tips??

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cartmel808
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Sat Dec 17, 2016 9:29 am

My 1st foray into lammie engines so this may be something of my own doing... but I've started to strip my GP 150 engine and when I've come to removing the Mag Housing it won't budge!
I tried 1st with the T spanners which progressed to instantly strip the threads in the extraction holes...
I then tried applying a bit of heat around the casing with blow torch & tapping around the housing with rubber mallet but still wouldn't budge... Ive even tried hammering the crank through from the sprocket side to drift the mag out - this got it to move but only by about half a mil & it's still well solid!
Any suggestions please??


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LI150
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Sat Dec 17, 2016 9:37 am

Lots of heat and hammer the crank, this has worked for me.

cartmel808
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Sat Dec 17, 2016 9:54 am

Thanks for the reply... I'm just a bit reluctant to keep banging away on the crank in case I end up cracking the casing... should I be applying the heat to the mag housing - or the crank case - or both?
Cheers - Graham.


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Scooterdude
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Sat Dec 17, 2016 10:13 am

All you'll do by hammering the crank from the drive side is damage it (which has probably happened all ready as they distort very easily) and yes possibly split the casing.
Lots of heat on the casing and around the flange area and maybe now you've got a small gap a good squirt of plus gas and leave overnight then try again.

Tractorman
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Sat Dec 17, 2016 10:43 am

Could try re-taping the holes to m8.

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LI150
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Sat Dec 17, 2016 10:54 am

Yes you will damage the crank. I heated up the casing, I like the idea of if you have got a gap to try get some type of lubricant inbetween

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coaster
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Sat Dec 17, 2016 11:01 am

Heat the casing, not the flange. Apply the plus Gas as suggested but don't be frightened of hitting the crank although you should factor its replacement into the rebuild ;)

Whatever you do, don't hammer on the outer part of the flange as it WILL break as I know to my cost :oops:

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HxPaul
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Sat Dec 17, 2016 11:06 am

LI150 wrote:Lots of heat and hammer the crank, this has worked for me.
This is the best way,especially if its an engine thats been stood for a few years.You will knacker the crank,but its the best way.

Scooterdude
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Sat Dec 17, 2016 11:27 am

So if all else fails your down to sacrificing either your crank or mag flange, think I'd go for saving the mag flange as you'll probably upgrade your crank anyway to the GP type.

hendy
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Sat Dec 17, 2016 4:02 pm

If you're going to hit the crank make sure you rotate it otherwise the housing 'tips' and jams in the casing.

Give the crank a couple of good whacks, rotate it 180 then another couple of good whacks. It'll come out in the end and your crank will be scrap metal. But as someone already said you'll be putting a new one in anyway.

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