Sludge trap plugs

[Drew Back]

I know this maybe a silly question but when you run these plugs in do they need to be flush with the crank?? and thats why you peen them in because they are still loose??I have never had to replace these so forgive a newbie question please..

[muskrat]

G'day Drew. No such thing as a silly question (might be silly answers), if you don't know, ask.
The plugs go in till flush or a tad recessed to the web. They are usually a tight fit but are centre popped for added security.
Cheers

[vinver]

Possibly you have later sludge trap plugs for the short stroke engine? I believe they are different in thickness, but same diameters and thread?
Different part numbers too.
Vincent

[Rgs-Bill]

  You fellas that have to replace with new sludge plugs for your sludge traps, make sure and get what you took out.  The newer ones can be thinner, and have a larger allen head fitting, which reduces the weight of the plugs, and of the crank shaft and affects where the balance factor is.  So theroetically you could have a lower speed vibration, or a higher speed vibration.  If you liked the balance factor of what you had before removing the sludge trap plugs, get the same weighted ones again, or possibly have to re-balance the crank..  This is what an old time Brit  bike mechanic told me, so just be aware that it can have an effect.  Some of the new replacement ones are much thinner in depth, and some have a huge allen head fitment on the top, which reduces the plugs weight, and changes the balance factors.  Musky would know much more about this than I would, because he had to do balancing for the race motors.  What say you Musky, please add to this, I am pretty sure I have some in-acuracies here , because it was 2nd hand info, and hearsay  .

[fido]

Must do my sludge traps some time, I've had my longstroke for 20 years and never had it apart

[muskrat]

I would be interested to know the difference in weight, new hex type v old slotted. I would imagine it to be only a few grams. This would alter the balance but I think for road use it would be insignificant, high speed road racing or land speed records might need to be tweaked.
 I replaced the originals in the A7 with hex type and didn't re-balance. No perceivable difference to comfort.
Cheers

[Billybream]

This got me thinking about effect on balance, but if both replacement plugs were identical the overall result would be close to original state, and for normal road use acceptable.

[bsa-bill]

Am I right to think that  whatever the difference is in weight between new and old  it will be doubled in how it affects balance as it's a minus at one point of the crank and plus at a point 180 degrees across the crank.
Probably will have less affect to most of us  than the potholes we encounter

[Drew Back]

I compared originals to the new ones and they were identical so I should be fine..I found original strait slot ones..

[East_Coast_BSA]

  You fellas that have to replace with new sludge plugs for your sludge traps, make sure and get what you took out.  The newer ones can be thinner, and have a larger allen head fitting, which reduces the weight of the plugs, and of the crank shaft and affects where the balance factor is.  So theroetically you could have a lower speed vibration, or a higher speed vibration.  If you liked the balance factor of what you had before removing the sludge trap plugs, get the same weighted ones again, or possibly have to re-balance the crank..  This is what an old time Brit  bike mechanic told me, so just be aware that it can have an effect.  Some of the new replacement ones are much thinner in depth, and some have a huge allen head fitment on the top, which reduces the plugs weight, and changes the balance factors.  Musky would know much more about this than I would, because he had to do balancing for the race motors.  What say you Musky, please add to this, I am pretty sure I have some in-acuracies here , because it was 2nd hand info, and hearsay  .

I call nonsense on this one.  A few grams of weight close to the center-line of the crank is probably unmeasurable from a balancing point, especially considering the total weight of the crank.  You're going to remove at least 5 times that amount of weight from your sludge trap (if it's full).  If this weight concern was true, when your sludge trap became full, the bike would vibrate itself apart.  We used to balance two-stroke race motors so they ran like a Swiss watch.  They didn't produce any more HP or last any longer than motors that weren't perfectly balanced.  It's not as critical as everyone thinks.