1990 Zephyr 550 Project

I picked this bike up back in August not even two weeks after buying a 750, the previous owner wanted to make a scrambler so it has oversized tires and some other questionable modifications(blue gauge lights).  I got it cheap because it does not run(two cylinders), supposedly the timing is off.  It smokes a ton of oil if you do start it. It does have a lot of powder coated parts that look nice, the paint is not original.  I am going to bring it back to the stock look. 

Right before I started tearing it apart the other day.

I've put on a stock rear fender, turn signals(K&S aftermarket) and removed the eBay parts(fender, rear light with integrated signals) that were on there. Going to get the signals wired up later today.  I have a bunch of parts on order like OE sized tires, brake lines that are the correct length, Renthal bars, spark plugs. Some new intake boots from webike Japan are on their way, I have a nice grab handle for it and some air box covers that were already delivered. 
 

I can’t see your photos, but I’m looking forward to seeing your progress. 

You might have an adblocker that blocks the shortened link type.  I will upload them to this post so you can see. 



 

 

 

that should keep you out of trouble for a while, looking forward to seeing it progress

Not a lot of visible stuff done today, I removed the whole rear fender to look inside of the frame and I am glad that I did.  There was a bunch of surface rust, hosed it down with various oils and cleaned them out.  Turn signals wired in(Deutsch DT plugs are nice), grab handle mounted.  I had to tap the mounting holes because when the frame was painted they didn't put a plug in.

     

Cold compression test.
#1: 172.7 PSI
#2: 166.5 PSI
#3: 141.5 PSI
#4: 168.7 PSI

I pulled the carbs off, like the Zephyr 750 I have it was held together with multiple types of screws and homemade brackets.  The float levels are completely off, tilting it slighting resulted in gasoline pouring out of the front.  The worst thing?  The previous owner pulled the engine apart to paint it, used WAY too much RTV to put it back together.  Instead of buying a 60 cent o-ring for the carb boot, he just used too much RTV, stupid. Spent the time to pull the whole bike apart to paint it, spent time making homemade airbox brackets to hold it together, 3d printed adapter rings for the carb but draws the line at buying an o-ring. 

   

Four new intake boots from Japan $78.69, import tariffs $66.66.  Awesome!

Carbs torn down to individual throttle bodies, cleaned and rebuilt.  Fuel rail o-rings were nasty. 
 
Picture is before ultrasonic cleaning and tearing them apart completely. 

Does anyone know the factory setting of the pilot screw for a ZR550?  The FSM and the Haynes manual both do not tell you.  I have them set 2 turns out.  I am going to be using the stock airbox and filter, jetting is OE.  I do have a full Kerker exhaust for it, any jetting suggestions(sea level)?  

Clutch cover removed, clutch disassembled and inspected.  Way, way, way too much RTV used by the previous owner.  I found a ton of liquid RTV sludge in the cover itself.    

Oil and filter changed, previous owner torqued the drain bolt with an impact and smashed the copper washer paper flat. 

Engine timing is completely off. 



Engine is set to TDC on #1 in the picture.  How likely is it that a valve is bent?  I am going to put the cams in the correct position and do valve clearances tomorrow. 





 

I believe the default for the pilot screws is 2-1/2 out, but I’m just going off memory.
A Kerker exhaust, I’m assuming is more “open” so you might need to go with one to two up on your jets, as well as a high flow air filter, such as a K&N. 
I love that you are doing your due diligence, and rectifying the sins of the previous owner. 

Is the pin count on the chain correct, don't forget when you fit the cam cover with the tensioner removed the inlet cam will rotate slightly "clockwise" as the guide pushes down on the chain between the cams

Stereordinary wrote:

I believe the default for the pilot screws is 2-1/2 out, but I’m just going off memory.
A Kerker exhaust, I’m assuming is more “open” so you might need to go with one to two up on your jets, as well as a high flow air filter, such as a K&N. 
I love that you are doing your due diligence, and rectifying the sins of the previous owner. 

Thanks, I will get mine set to 2 1/2 and up the main jet to #110/112.  

The cam caps have worn the camshaft enough that I can feel a groove with my finger nail, it's bad(looks bad too).  I should have taken a picture but my hands were covered in oil so I will do it later when I check the valve clearance. I have ordered a used head off of eBay. 

Wookie58 wrote:

Is the pin count on the chain correct, don't forget when you fit the cam cover with the tensioner removed the inlet cam will rotate slightly "clockwise" as the guide pushes down on the chain between the cams
 

The pin count is now correct, and I am glad you said something about the inlet cam because it is pointing slightly clockwise now.  I am about to fit the cylinder head cover, followed by the tensioner then I will take the cover back off after rotating it several times and check the valve clearance. 

The cam chain tensioner cap bolt just stripped out at 7nm, so the engine side of things is going to be on hold until I can get a new one.