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Simple decomp mod. Comments?

PostPosted: Sun Mar 17, 2013 7:52 pm
by edfmaniac
I read about an easy way to fix the problem of losing oil pressure in the cam when removing the decomp parts. Once you have removed everything from the camshaft, thread the 5mm hole where the decomp pin used to be with a 6.0mm x 1.00 tap, reinsert the small cam that operates the decomp pin with the flat surface facing the threaded hole, and lock in place with a 6mm x 12mm set screw. You may have to take 1/2mm or so off of the socket end to countersink it slightly. Voila! Oil flow problem solved. Just make darn sure that you clean and thread lock that set screw.

Using this method, you can easily restore the cam to original operating condition. I don't think the threads will do any harm to the pin once reinstalled. I'll post pics once my batteries recharge and if there is any interest, but it's a pretty simple concept.
threads.JPG
plunger.JPG
setscrew.JPG

Re: Simple decomp mod. Comments?

PostPosted: Sun Mar 17, 2013 9:53 pm
by edfmaniac
And here's the final product. As soon as I make sure there aren't any surprises with my head work, it's getting sent off to Megacycle for an X4 profile. :D
voila.JPG

Re: Simple decomp mod. Comments?

PostPosted: Sun Mar 17, 2013 10:48 pm
by DAVID THOMPSON
some one makes those little screws with a nylon lock piece in the side of them to make it stay in
i have seen my father in the machine shop using them
i think there still some there on the shelf some where
will see if the box has a name on it
do thread lock that thing or you will have a mess on your hands.

dave

Re: Simple decomp mod. Comments?

PostPosted: Mon Mar 18, 2013 2:47 am
by breakwellmz
Hi

You may be familiar with Loctite 638.Brilliant stuff,it`s what i would use,and have used many times over the years.
An alternative would be to peen with a punch.

http://www.ebay.co.uk/itm/Loctite-638-H ... 5d3403712c