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Motorcycle Repair/89 honda 250nx

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Question
I have just recently bought a nx250 that was in
Pieces and now have it all put back together except
Setting the timing I have the piston at tdc but need
To know where the loabs on the cams need to be
If there suppose to be up down facing each
Other or pointing away from each other

Answer
Mark, on a single cylinder engine, the cam timing is set so that the cam lobes are down, leaving the engine at the top of the compression stroke.

I haven't worked on an NX250, but generally there are some marks on the camsprocket that either indicate that the correct position should be at 12 o'clock (usually a dot) or sometimes there are parallel marks on the sprocket indicating that they be parallel with the top surface of the cylinder head. On some bikes a notch on the end of the camshaft is located on the split between the cam bearing surfaces.

A quick search on the web found this...

http://img4.fotos-hochladen.net/uploads/meinenixev9d0gbty3z.jpg   among a number of other images that came up in a search for HONDA NX250 cam timing....  This image has a note mentioning that this is the way they found the cam timing and after it was adjusted, the bike ran much better... so if that is correct then it looks like the notches go UP and the parallel lines go even with the head.

http://www.bcmtouring.com/forum/motorcycles-f13/attempt-replacing-valve-seals-wi

http://www.bcmtouring.com/forum/attachments/100_9042.jpg-480470d1391874051 seems just right.


Bill Silver  

Motorcycle Repair

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Bill Silver

Expertise

Need help with vintage Hondas from the 1960s? I am an expert with 250-305cc bikes in particular and most all of the other pre-91 models, in general. I do NOT claim to have a great deal of experience on Gold Wings, Cruisers, ATC/ATVs and dirt bikes.

Experience

I have owned/ridden/maintained Honda motorcycles for 35 years. I have written five books on Honda repairs and collecting. I was a service manager for two Honda shops back in the 1980s.

Organizations
VJMC (Vintage Japanese Motorcycle Club) of North America

Publications
VJMC newsletter, as editor for two years and as contributing editor currently.

Education/Credentials
3 years auto shop in high school, teacher's aide in Automotive Technology in Jr. College, Diesel mechanic course in college, self-taught mechanic and automotive writer.

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