Crushing
New Member
I have a 1967 merc 110 9.8hp how do u set points with out special equipment mine had grease on them
1967 merc point setting
- Thread starter Crushing
- Start date
VicS
Well-Known Member
Resurface them as necessary. Its not practical or necessary to remove deep pits but the "pips" must be removed in order to measure the gap. clean all traces of oil or grease from the contact surfaces. ( I'd say replace if necessary but I have just looked up the price 
) make sure there is plenty of pressure in the spring, bend it a bit if necessary as by now it could be relaxed a bit
Adjust the gaps to the specified setting ( 0.020", I beleive ) when at their widest open with a feeler gauge. Be sure to tighten the screws firmly and recheck the gap after doing so.
The setting is correct when you can feel a gentle drag on the feeler gauge as you draw it between the contacts.
Draw a piece of paper between them too to ensure all oil and grease is removed.
I hope that helps I cannot find any specific instructions in the owners manual or any decent diagrams.
there should be no major differeneces from setting the points in an old motor car distributor except for the fact that there are two sets
) make sure there is plenty of pressure in the spring, bend it a bit if necessary as by now it could be relaxed a bitAdjust the gaps to the specified setting ( 0.020", I beleive ) when at their widest open with a feeler gauge. Be sure to tighten the screws firmly and recheck the gap after doing so.
The setting is correct when you can feel a gentle drag on the feeler gauge as you draw it between the contacts.
Draw a piece of paper between them too to ensure all oil and grease is removed.
I hope that helps I cannot find any specific instructions in the owners manual or any decent diagrams.
there should be no major differeneces from setting the points in an old motor car distributor except for the fact that there are two sets
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Crushing
New Member
Did as u discribed the spark plugs nkg b7hs I set to .030 it seems pistons changed the gap to .012 what should gap be or are these the wrong plugs
VicS
Well-Known Member
Unsuitable plugs.
According to the manual a 1967/8/9 model should originally have had Champion L4J plugs gapped at 0.030"
but a 1966 model had J7J gapped at 0.025"
L4J are 1/2" reach plugs but J7J are only 3/8" reach !
Both are now obsolete
B7HS are 1/2" reach but the electrode may project further than the old Champions
You may have to change to a shorter reach plug
EDIT
found the equivalents table I was looking for
The NGK equivalent of Champion J7J is B6S ( 3/8" reach)
and of L4J is B7HS so ought to be correct ! ( the sealing washers are in place ??)
I think I would try B7S, or B6S which is one grade hotter but it would be wise to consult an authorised Mercury dealer
According to the manual a 1967/8/9 model should originally have had Champion L4J plugs gapped at 0.030"
but a 1966 model had J7J gapped at 0.025"
L4J are 1/2" reach plugs but J7J are only 3/8" reach !
Both are now obsolete
B7HS are 1/2" reach but the electrode may project further than the old Champions
You may have to change to a shorter reach plug
EDIT
found the equivalents table I was looking for
The NGK equivalent of Champion J7J is B6S ( 3/8" reach)
and of L4J is B7HS so ought to be correct ! ( the sealing washers are in place ??)
I think I would try B7S, or B6S which is one grade hotter but it would be wise to consult an authorised Mercury dealer
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Crushing
New Member
Yes seals are in place on plugs
Crushing
New Member
The merc dealer said I have right plugs someone must have dun some type of mod to engine. What can I use to mesure the the clearance for pistion ands cylinder head for correct spark plug
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