1979 KZ 650SR White puffs on decel.

So, i picked this bike up a couple months ago. it had 11k miles on it, and the story is that it had sat in a barn for a good 15+ years, was rebuilt about 2 years ago at 8k miles from the ground up. i've put about 1000 this month.

It looks like it was pretty well gone through. PO put on pods, a V&H 4-1 exhaust and rejetted. even has a beautiful fresh paint job. The bike runs great with two caveats:

1) she is a real bear to start if shes not already warmed up. Always have to be on full choke and nurse it gently till i can have the throttle rolled on and drop the choke while keeping the RPMs up. I have no experience with these motors, so perhaps its normal, but its unlike anything i've experienced before.

2) once shes waremd up, particularly if the motor has been running hard at all, i get what looks like oil burn off when the motor is decelerating. Most noticeable when rolling up to a stoplight or if i rev the engine. I believe this may be a valve seal issue, but having never worked on a motorcycle engine before, i'm not sure how big of a PITA this would be to fix, or if its really crucial that it gets attention before winter. thoughts?

Also this is my first bike, and i'd like to do all my own work on it, but i'm not a super hardcore mechanic, i have basic set of tools and a good understanding of the theory and i'm not afraid to get my hands dirty, though till now i've only worked on cars. Should i be concerned about doing my own work on this bike? I understand valve adjustments sound like a real bear of a task. Any advice on things to look for would be great.


oh, one other thing... the exhaust is blued pretty heavily, while aesthetically it doesnt bother me, is it indicative of something i should be concerned about?

from_dust wrote: 1) she is a real bear to start if shes not already warmed up. Always have to be on full choke and nurse it gently till i can have the throttle rolled on and drop the choke while keeping the RPMs up. I have no experience with these motors, so perhaps its normal, but its unlike anything i've experienced before.

Not normal. Hard starting can be a lot of things: usually carb problems, can also be ignition problems or valve clearance as well.

from_dust wrote: 2) once shes waremd up, particularly if the motor has been running hard at all, i get what looks like oil burn off when the motor is decelerating. Most noticeable when rolling up to a stoplight or if i rev the engine. I believe this may be a valve seal issue,

Maybe. Could also be rings. I would do a compression check (cold and hot) and see what it is.

from_dust wrote: Also this is my first bike, and i'd like to do all my own work on it, but i'm not a super hardcore mechanic, i have basic set of tools and a good understanding of the theory and i'm not afraid to get my hands dirty, though till now i've only worked on cars. Should i be concerned about doing my own work on this bike? I understand valve adjustments sound like a real bear of a task. Any advice on things to look for would be great.

You need a factory service manual.

from_dust wrote: oh, one other thing... the exhaust is blued pretty heavily, while aesthetically it doesnt bother me, is it indicative of something i should be concerned about?

No, they all turn blue.