• Required reading for all forum users!!!

    Welcome!
    Register to access the full functionality of the GSResources forum. Until you register and activate your account you will not have full forum access, nor will you be able to post or reply to messages.

    A note to new registrants...
    All new forum registrations must be activated via email before you have full access to the forum.

    A Special Note about Email accounts!
    DO NOT SIGN UP USING hotmail, outlook, gmx, sbcglobal, att, bellsouth or email.com. They delete our forum signup emails.

    A note to old forum members...
    I receive numerous requests from people who can no longer log in because their accounts were deleted. As mentioned in the forum FAQ, user accounts are deleted if you haven't logged in for the past 6 months. If you can't log in, then create a new forum account. If you don't get an error message, then check your email account for an activation message. If you get a message stating that the email address is already in use, then your account still exists so follow the instructions in the forum FAQ for resetting your password.

    Have you forgotten your password or have a new email address? Then read the forum FAQ for details on how to reset it.

    Any email requests for "can't log in anymore" problems or "lost my password" problems will be deleted. Read the forum FAQ and follow the instructions there - that's what we have one for...

  • Returning Visitors

    If you are a returning visitor who never received your confirmation email, then odds are your email provider is blockinig emails from our server. The only thing that can be done to get around this is you will have to try creating another forum account using an email address from another domain.

    If you are a returning visitor to the forum and can't log in using your old forum name and password but used to be able to then chances are your account is deleted. Purges of the databases are done regularly. You will have to create a new forum account and you should be all set.

Need help identifying the mechanical advance unit

  • Thread starter Thread starter DrDoot
  • Start date Start date
D

DrDoot

Guest
I can't tell if this is a Nippon Denso mechanical advance, or a Kokusan brand. Marking should be either ND or KD, and I can't tell which. Any of you experts out there think you can tell?

Pics are posted at:
http://img.photobucket.com/albums/v490/gs1327/80%20GS550L/GS550advancerotherside.jpg
and
http://img.photobucket.com/albums/v490/gs1327/80 GS550L/GS550advancercloseup.jpg

and
http://cgi.ebay.com/ebaymotors/ws/e...e=ADME:L:RTQ:US:1&viewitem=&item=250035582654


Can't find any conclusive identification in old threads. Thanks much.

-RAY
 
Last edited:
Yes, all three links are for the same unit, just need to know whether it's Kokusan or Nippon Denso.
 
I dont think there were any kokosan advance units. They were all ND.
It would not matter anyhow as all crankshafts had the same indent slot for the advance unit to mate into, so they would have to be the same. The KD vs ND ignition question only applies to the breaker plate. The mount holes for the point sets are different spacing on KD and ND setups. Either plate will fit the mechanical advance unit.

E.
 
service manual should say

service manual should say

Check the book for a 550, but in the Clymer manual for the 650s, it says the chain drive models use Kokusan ignition while the shaft drive models (of the L model is one) use Nippon Denso.
 
While it seems the mechanical advance units from older 550 bikes would be compatible with the '85 model, would larger engine sizes have the same mechanical advance size as smaller engine sizes? Most likely? Such as from a GS850... I found one that looks identical but I don't know if the size would be different.
 
SqDancerLynn1 said:
Their is a difference as to where the timing marks are
Click to expand...

Thats interesting. Yeah really. :-) Not having measured the timing marks on all GS models, I can only speculate. Considering all four cylinder GS models have the same crankshaft throws, then the only viariable for timing marks would be rpm range. Some models do have a slightly higher redline than others, so technically, the full advance marks could be slightly different. The static timing marks should not be since advance required is a function of rpm. (and yes heat and load, but to keep it simple :-) ) Anyway, considering the narrow range of upper rpm variance between GS models, the difference in max advance marks (if any) should be slight to nil. I will hazard a guess that if you set any GS four cylinder to 32 deg max advance, it will run just fine. 32 deg BTDC BTW, is the point at which the firing sequence is initiated, not the crankshaft position when the air/fuel mixture explodes and exerts a force on the piston pushing it downwards. If combustion was completed at 32 deg BTDC, the engine would stop......ABRUPTLY. :-)

E.

Earl
 
All of the advance units are interchangeable, as i said timing marks are different. Checked my parts bin difference is weather the advance unit is for points or elect ign setup
 
SqDancerLynn1 said:
All of the advance units are interchangeable, as i said timing marks are different. Checked my parts bin difference is weather the advance unit is for points or elect ign setup
Click to expand...

Ahhh, the difference then would be due to lag time between points and electronic systems. Shouldnt be much.

E. :-)
 
On most newer GS bikes the initial timing is not adjustable anyway. For example a 650 is 10 degrees before with 34 degrees of advance between 3400 and 3800 rpm. So the real issue would be does it naturally start out at 10 and will it advance the proper amount at the proper rpm. IF you have springs you could move them over to this unit and test it.
 
You must log in or register to reply here.
Back
Top