Neil_Y
Well-Known Member
Anyone have some some maintenance details and maybe a coil for an old 2 stroke with points? It was running great but I suspect coil or ht lead problems and I'd like to confirm the points gap.
points gap for 2.5 mercury?
- Thread starter Neil_Y
- Start date
rotrax
Well-Known Member
If you clean the points and set them around 10-15 thou or 0.3-0.4 mm you wont be far out. For simple conversion 0.1 mm is about 4 thou. Many simple flywheel magnetos relied on the breaking of the contact points to set the timing, the gap not being too important as long as it had one. Severe wear of the heel can mean it is not possible to get the breaking point correct so the timing will always be out. I expect you will get a manual or handbook from EBAY or the internet. Good Luck.
30boat
N/A
My 2.5 which is now in bits has no provision for gap adjusting.If you need the manual pm me your email and I'll send it to you.
VicS
Well-Known Member
You do not give the serial number or the age. Fairly old I guess if it has points ignition.
You may be able to find an owners manual which may give the points gap in the Brunswick Marine Download Center
The ignition timing is dependent on the gap being set correctly so important to find what it should be. Most other small Mercuries have a gap of 0.020" so would be surprised if it is any different.
30boat
N/A
This is from a 1990 engine.No adjustment possible.
VicS
Well-Known Member
This is from a 1990 engine.No adjustment possible.
Looking at the picture I'd have expected that to be adjustable. Not by much maybe but adjustable to some extent.
I'd expect the rusty screw to pass through a short slot ( hidden by the washer) in the bottom plate to allow for some adjustment.
I expect to be able to slacken the screw and then move the bottom plate a little with the aid of a screwdriver in the notch to the right of the screw head, adjusting the position of the bottom plate/fixed point to give the correct points gap.
Is that not so?
The screw does not pass through a slotted hole in the bottom plate ?
Tugw
Well-Known Member
Absolutely correct,You will need to put a setting ring on the shaft to get the correct gap(this replaces the cam on the flywheel)
30boat
N/A
When I dismantled the engine I worried about the gap/timing but the workshop manual doesn't mention anything as far as I could find.I was expecting some way of adjusting the gap to compensate for wear and also a way of setting the timing but everything appears to be fixed.