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By Dez
#7005
Hi all.I am trying to reduce the slack in my mag chain. The manual says loosen three bolts in timing chest and move casing backwards slightly to achieve correct tension. Problem is the the holes are holes, not slots so centres seem fixed with no adjustment possible without some serious drilling and filing!!any ideas gratefully received. Happy 2017 all. Dez
By Dennis C
#65288
I have not as yet found one that won't adjust, it seems strange that it has got through 50ish years without being adjusted, are you sure it's not just stuck with gasket sealant?.
By Mark M
#65291
I agree with Dennis, something isn't right. It may be stuck with gasket cement. You are loosening the bolt heads INSIDE the timing chest? (sorry for emphasis, I'd do it in italics if possible!) They are partly hidden by the sprocket. The 3 nuts on the outside just secure the magneto to the adaptor plate. The holes should already be slotted to allow adjustment to take place by the way.


REgards, Mark
By Dez
#65293
Thanks all. Three bolts in timing chest pass straight into three tapped holes in housing behind. Don't know if it is relevant but someone has fitted boyer electronic ignition so has something been removed with the magneto?..definitely not just stuck with gasket goo, and centres are fixed!
By vince
#65294
Hi, what size bolts hold the boyers system on? I,m thinking its bigger than original hence no adjustment in the holes. Vince
By Dez
#65305
Hi Vince. Three 1/4in bolts hold it on. Presently got about 1in slack on bottom run!! Accurate timing not possible. Have ordered new chain from our hosts as I suspect mine must but 50 yrs old with that amount of wear. Will fit new chain and see, but suspect may have to operate on rear of timing chest to get any future adjustment. Will let you know. Thanks again. Dez
By Dez
#65306
Hi Vince. Three 1/4in bolts hold it on. Presently got about 1in slack on bottom run!! Accurate timing not possible. Have ordered new chain from our hosts as I suspect mine must but 50 yrs old with that amount of wear. Will fit new chain and see, but suspect may have to operate on rear of timing chest to get any future adjustment. Will let you know. Thanks again. Dez

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