|Sea Pub Magneto timing question
Post Number: 3
|Posted on Tuesday, June 05, 2007 - 05:22 pm: ||
In 1976, I installed the Kermath into my Tumlaren 28' sailboat.
I sold the boat in 1984 but the new owners called me early this spring to clear up some issue with the registration of the vessel and we became sort of friend with them living and sailing nearby.
Yesterday, I tried to bring to life, the old Kermath and low and behold, after 3 hours I got her runnning very nicely.
However, at speed, it sounds like the timing is not right, e.g. it doesn't quite come up to the RPM's it should.
On the Magneto there are some marks (4 or 5) representing some degree of advance or retard, how many degrees does each marks represent and where should it be adjusted to?
I got it on the 1st mark in the advanced position.
Lawrence T Wolfe
Post Number: 245
|Posted on Tuesday, June 05, 2007 - 07:01 pm: ||
The magneto turns at 1/2 the speed of the crankshaft so normally the distance between marks are 1 degree. It takes a big move at the mag to get the same change on the crank. You could just turn the mag while its running and find the best spot.
Lawrence T Wolfe
Post Number: 246
|Posted on Tuesday, June 05, 2007 - 08:00 pm: ||
Oops a small move at the mag makes a big change on the crank. Which mag do you have.
Post Number: 4
|Posted on Wednesday, June 06, 2007 - 11:56 am: ||
thanks for your reply.I am not sure of the make of the Mag but I know it's
origional. The Kermath was sold new to me 35 years ago as an Atomic 1. I
will ask the present owner of the boat to have a look at it and see if he
can make our the MFG of the Mag.
Adjusting it while it's running seems a good way of getting it right enough.
Next time I visit the owner I will experiment with it; it is a bit of a bear
to get at the bottom nut that holds the mag. Prently the mag is in the
advanced position on the first mark before TDC and the motor starts and
idles fine, only at higher RPM it sounds to me that it is not coming up to