1978 KZ650 Cafe Racer "Jellybean"

Teaser... :)

Carb_teaser_2.jpg
 
I really hope that the paint used for those carbs is resistant to gas. I know you stated it was dupli High Heat I believe. Please let me know how it goes.
 
Carb Rebuild: Reassembly - plus a few final touches

Well Gents and Ladies, I finally finished the carbs! I lost count of the hours invested, but I'm happy with the results. Before I could start reassembling the carbs, I had a few things I had to do, such as replace some of the hardware, and finish polishing the float bowls.

IMG_0122.JPG


The float bowls weren't bad but it was rather difficult getting into the hard to reach areas with the Dremel. I ended up using a pointed polishing bit that came in the small kit I purchase for the Dremel tool (shown earlier in the build). It didn't get everywhere, but it did a decent job.

IMG_0125.JPG


All done, fingerprints included.

The next thing I had to do was replace the screws that hold the carb cap and float bowls to the carb bodies. They were rusting and stripped out. I went to, what I think is the best place to get quality hardware - quickly, McMaster Carr! I went with the Socket Cap screws to avoid the stripping issue, as well as their clean look. Here is the spec for the screws:

Stainless Steel Low Head Socket Cap Screw
M4 Size
16mm length
.7mm pitch

IMG_0131.JPG


Two packs of 25 plus shipping was less than $15! Good investment!

IMG_0153.JPG


You'll have to get some lock washers as well because the stock ones do not come off the old screws without hassle.

Ok, on to assembly! I went ahead and replaced all the hardware I could that came with the rebuild kits. Here's a little bit of a walk through of the process I performed for each carb.

NOTE: feel free to use assembly oil on the slides, it can only help. I used bike chain lube.

Build-2.jpg


Here is where the parts go with the carb sitting on its top.

IMG_0135.JPG


All in.

Build-1.jpg


This is the remainder of the parts and their locations.

IMG_0137.JPG


Before I put the slide in, I swapped out the needles, and made sure the c-clip was in the right position. Here's all the parts laid out in their order.

IMG_0139.JPG


Placing the c-clip on the middle slot is a safe location. It's a good starting point for tuning the carbs, and typically you shouldn't have to adjust the needle height in order to get them running right. When I pulled the needles out the first time, the had it set to the lowest slot which could have been compensating for another issue... not sure. Anyway, all better now.

I did encounter an issue with the slides in two of the carbs. They were binding on the base of the carb bore. This freaked me out at first because it wouldn't budge once it got to a certain point. I decided to take a toothbrush to the bottom area of the bore to make sure there wasn't any dirt causing the issue, and sure enough, once I brushed it out, (and with a little lubricant) it slid right it.

IMG_0142.JPG


Here's is the slide getting stuck and not closing all the way.

IMG_0143.JPG


After the toothbrush and a little lube, it was in. Shows how tight the clearances are.

Alright, time to put it together! Have a manual with you to help. If you don't have a manual, go on BikeBandit.com and print out the part diagrams they have on their website.

IMG_0154.JPG


Getting there...

IMG_9584.JPG


DONE!!!

IMG_9585.JPG


IMG_9586.JPG


IMG_9587.JPG


IMG_9588.JPG


IMG_9582.JPG


I'm really happy with how they turned out. Now on to fire up the old girl and move on with this build!!!
 
Very nice job on the work writing up and doing the carb rebuild! I bookmarked it. Have two sets of the same carb that I've been putting off doing this to. Inspiring, really makes me want to get mine finished. Did you go up a few steps with the jets for those pods?
 
canyoncarver said:
Very nice job on the work writing up and doing the carb rebuild! I bookmarked it. Have two sets of the same carb that I've been putting off doing this to. Inspiring, really makes me want to get mine finished. Did you go up a few steps with the jets for those pods?

Thanks! Yeah, it's in the write up on page 1...

11) 4 Pilot jets - 17.5 (based on research for a KZ650 with pods and a mild exhaust) - JetsRus.com
12) 4 Main Jets - 115 (based on reseach for a KZ650 with pods and a mild exhaust) - JetsRus.com


I put in several hours of research and consulting resources to find those numbers. I'll let you know how they work for me when I get it running.
 
Getting ready to do the same thing, great work. I am also curious about the paint, i want go black on the main portion of the carb bodies. Haven't decided between paint and powdercoating. I don't know if you use kz650.info, but they have a thread just dedicated on what people are using for jets based on environment and modifications to the bike. The site is great resource for the bike.
 
bowman41 said:
I really hope that the paint used for those carbs is resistant to gas. I know you stated it was dupli High Heat I believe. Please let me know how it goes.

Getting ready to do the same thing, great work. I am also curious about the paint, i want go black on the main portion of the carb bodies. Haven't decided between paint and powdercoating. I don't know if you use kz650.info, but they have a thread just dedicated on what people are using for jets based on environment and modifications to the bike. The site is great resource for the bike.

Here is the paint I'm using, which is gas and oil resistant. In regards to powder coating or paint, I would definitely recommend paint. This is because you can avoid the baking process required for powder. I'm not sure how the different types of metal that are in the carbs would respond to the heat. Since the enamel resists oil, gas and high heat, I see no added benefit to using powder coating, except a higher level of durability, but hopefully, your carbs don't "need" to be that durable. :)

photo.JPG
 
I will be curious to see how the paint holds up, I used that to paint my engine. I would love to paint my carbs black and the local powdercoater wanted $150 to do it so if the paint holds up it would be great alternate.
 
Nice work, and great documentation! I know all too well that stopping to take pictures and getting them organized/posted is project in and of itself!
 
Thanks for all the compliments guys!

Well, I finally got her started. I finished up assembling the carbs, RTVing the fuel connections between each carb, and hooked up the new battery. I also had to get new fuel line because the old one had rotted away. The fuel line, and nice braided plastic piece from Dime City, was too hard, and wouldn't flex enough for me to get it on the fuel port. So I grabbed one of my wife's candles and held the end of the line over the flame until the outside was slightly tacky, and it went right on. That was the easy part.

IMG_0190.JPG


It worked like a charm, and the garage smelled great too! :)

IMG_0192.JPG


All hooked up and ready for me to jump on it for a while...

Finally, after almost three years, its up and running. It only took a few kicks and a lot of choke to get going, but I could tell things were working much better than the last time I had it running. That was the good news. The bad news is, it's having the same problems it had as well. Backfiring out of the left side of the carbs, and smoking out of both exhaust pipes. I'm slightly stuck on where to go from here. I remember being stumped the last time, and that sucked. Here's a video of it running. Let me know what you guys think. I'm going to look into timing for the moment. I'll keep you posted!

http://www.youtube.com/watch?v=OASawkT7Jyk&feature=youtu.be
 
It's lean... you didn't answer your phone when I called. ::)

Wait... you have checked carb sync and ignition timing first right? Those would be priority #1 before determining lean/rich.... but i still think that "sounds" like a lean backfire
 
I would have to agree on being lean since it required a lot of choke, but I had a similar problem with mine and ended up being timing.
 
Re: 1978 KZ650 Cafe Racer "Jellybean" - TIMING ISSUES

After adjusting the timing several times, it looks like the advance mechanism isn't working properly. The "F" line is lining up with the "high" rpm timing mark way before the recommended RPM. BSully and I have been diagnosing this, and we think it's the springs. Apparently they do not make replacement springs for my bike so I have been scouring ebay for replacements. Here's my question... Was this ignition advance unit used on other models like the 550 or the 750? I ask this because there are several units for sale for the the 550 and the 750, but few for the 650. Thoughts guys? Thanks!
 
A quick look at kawasaki.com says that 1977 through 1980 kz650 share the same advancer. Check this link out it discusses using other advancers http://forums.kz650.info/index.php?topic=7449.0
 
Thanks a lot Jeff! That definitely answers my question! I'm going to share this info for the DTT members.

Ignition Advance unit Guide:

kz750
advancer 21148-1013 from 10 degrees BTDC @ 1050 rpms to 40 degrees BTDC @3650 rpms
Model (12):
KZ750-E1 (1980)
KZ750-E2 (1981)
KZ750-E3 (1982)
KZ750-F1 (LTD Shaft) (1983)
KZ750-H1 (LTD) (1980)
KZ750-H2 (LTD) (1981)
KZ750-H3 (LTD) (1982)
KZ750-H4 (LTD) (1983)
KZ750-L3 (1983)
KZ750-N1 (Spectre) (1982)
KZ750-N2 (Spectre) (1983)
KZ750-R1 (GPz) (1982)


kz650
advancer 21148-1022 from 10 degrees BTDC @ 1000 rpms to 35 degrees BTDC @ 3200 rpms
Model (3):
KZ650-H1 (CSR) (1981)
KZ650-H2 (CSR) (1982)
KZ650-H3 (CSR) (1983)
(Would assume this part was also used on the other 81 and later models)


kz1000 and 1100
advancer 21148-1020 from 10 degrees BTDC @ 1000 rpms to 40 degrees BTDC @3400 rpms
Model (40):
KZ1000-J1 (1981)
KZ1000-J2 (1982)
KZ1000-J3 (1983)
KZ1000-K1 (LTD) (1981)
KZ1000-K2 (LTD) (1982)
KZ1000-M1 (CSR) (1981)
KZ1000-M2 (CSR) (1982)
KZ1000-P1 (Police 1000) (1982)
KZ1000-P10 (Police 1000) (1991)
KZ1000-P11 (Police 1000) (1992)
KZ1000-P12 (Police 1000) (1993)
KZ1000-P13 (Police 1000) (1994)
KZ1000-P14 (Police 1000) (1995)
KZ1000-P15 (Police 1000) (1996)
KZ1000-P16 (Police 1000) (1997)
KZ1000-P17 (Police 1000) (1998)
KZ1000-P18 (Police 1000) (1999)
KZ1000-P19 (Police 1000) (2000)
KZ1000-P2 (Police 1000) (1983)
KZ1000-P20 (Police 1000) (2001)
KZ1000-P21 (Police 1000) (2002)
KZ1000-P22 (Police 1000) (2003)
KZ1000-P24 (Police 1000) (2005)
KZ1000-P3 (Police 1000) (1984)
KZ1000-P4 (Police 1000) (1985)
KZ1000-P5 (Police 1000) (1986)
KZ1000-P6 (Police 1000) (1987)
KZ1000-P7 (Police 1000) (1988)
KZ1000-P8 (Police 1000) (1989)
KZ1000-P9 (Police 1000) (1990)
KZ1000-R1 (Eddie Lawson Replica) (1982)
KZ1000-R2 (Eddie Lawson Replica) (1983)
KZ1100-A1 (Shaft) (1981)
KZ1100-A2 (Shaft) (1982)
KZ1100-A3 (Shaft) (1983)
KZ1100-B1 (GPz) (1981)
KZ1100-B2 (GPz) (1982)
KZ1100-D1 (Spectre) (1982)
KZ1100-D2 (Spectre) (1983)
KZ1100-L1 (LTD Shaft) (1983)
 
Back
Top Bottom