distributor

[ronnie]

hi , ive stripped down my distributor 25D for a general clean and check. Im needing some advice on the mechanical advance.The 2 springs that are fitted are slightly different , one having about 7 turns to the spring and the other which is a stronger spring having only 5 turns . The heavier spring is not as tightly fitted from pin to pin as the weaker pne , looks like its stretched , bit loose on the pins ,do you think that will have any bearing on the performance
ronnie

[bmcecosse]

That's exactly how it should be - the advance is in two stages. What advance number is stamped on the bob weight nose ???

[ronnie]

hi bmc
the number on bob weights is 13 , but what about the spring that seems stetched ?? do you think thats ok

[bmcecosse]

Thanks for that - so that's 26 degrees mechanical advance. And yes - one spring should be loose - it only comes into play at higher revs.

[ronnie]

thanks bmc , i was convinced one of the springs was knackered and would have changed it had you not put me wise
cheers ronnie

[bmcecosse]

Check the vacuum advance is working too! When 'upgrading' a dizzy - most will cut ~ 3/16" off the end of the tip of the nose of the bob weight, thus allowing more mechanical advance. Generally - a modified A series wants about 34 degrees total advance - as your dizzy sits now, you have to set 8 degrees static advance - which is far too much. So - cutting the tip to allow 30/32 degrees mech advance means ~ 4/2 degrees static advance which is much better....

[M25VAN]

This site has some info on how the distributor all works....

http://www.starchak.ca/tech/pdfs/lucastuning.pdf

There is also lots of mini stuff for Mr BMC.

[brucek]

Could also try this one too

http://simonlacey.com/pages_new/content ... ebuild.htm

[ronnie]

cheers guys