Topic: '83 CB650z - rat cafe

[madsen5]

I'm a new member from denmark. I have been lurking for a while but now i want to show you what I'm up to.

First of all I have to tell you that this is a budget project. The main purpose is to have an excuse to leave the girlfriend and two kids in the house and 'escape' into the garage once in a while. But when I do I might as well try and get something out of it.

I bought the bike a couple of months ago for the equivalent of a 1000 dollars which is very cheap in a country that have 180% tax on new cars and bikes (I'm not kidding you). It was looking allright and was able to start and run though it was very rough. It has been crashed but I didn't think it was serious. You can see the before shot - it's the one with the blue tank and other blue stuff.

My goal is to make a very simple, clean and perhaps a little ratty Cafe Racer.

First thing to do was get the plated. In denmark this means the bike is looked over and checked in relation to safety and that it hasn't been modified to much. I only had to get new tyres, repair a few electrical problems and give the bike a general tuneup. And it passed the test.

In the last month I have been riding the bike and started to make e few changes:

• Replaced the front fender with generic glassfibre part
• Removed the instruments
• Replaced the bars with clipons
• Replaced front light with eBay light
• Replaced the tank with CX500 tank - I like the indents and the look of it when lying flat
• Made my own seat with a seat cowl of a Suzuki GSXR600 - it still needs some work
• Simple backlight and plateholder

I think its starting to take shape. Still have to do:

• Rebuild front end and place clipons under the upper fork clamp
• Mount electronic tach and bicyclecomputer in aluminum bracket
• Complete new wiring - very simple
• Free up the triangle behind the carbs, battery goes under the tank I think
• Mount K&N oval filters and re jet the carbs
• General cleanup and removal of excess parts, framebrackets etc.
• Hope to find something cheap for a rearset
• But most importantly - have fun as I go

There is a few pics of the bike at the stage that it's at right now. I will keep it in primer till the shape is finished. Please give me a lot of feedback and ideas, but keep in mind that its a budget project. I would love a tank/seat set from Benjie's and a completely rebuild engine, but I don't have that kind of money for this.

Hope my english is not all too broken

[madsen5]

And a few more pictures....

[scunny]

hi madsen, looks like a good start on the bike. as for rearsets I just cut the existing mounting plates down

[Hush]

Congratulations, you have made an ugly bike look good.
Your english is nearly perfect too.

[Pinhead]

I thought the 650 went to DOHC in '83 and the Z model was only in '79 and already had rearsets...

I like the looks of that tank. Did it take any modification to mount it to the frame?

[CBJoe]

Holy Crap 

What exhaust system is that?  I've never seen that on a 650 before.

Oh yeah    Looks good.

Cheers, Joe

[madsen5]

Thanks for all the compliments on the bike 

I think it's actually an '82 model sold in '83. Also the European models where a little different than the US ones. The z was sold all of the years here. But I'm not really sharp on model history.

Both the frame and the CX tank is unchanged, but i made a few very simple brackets to make it fit. The front mounting points on the frame has been moved down and forward a bit and the tank is lifted around 7 cm from the frame in the back. I have mounted it a lot flatter than it is on the CX. I think that gives it a more aggressive look. Also it gives me a lot of room between the frame and tank in the back. I hope to fit a battery in there.

The exhaust is a Marshall Deeptone and is very common here. It sounds fantastic but unfortunately it has been scraped in a crash. The idea is to repair the scrape, paint it flat black and wrap the headers.

Scunny - did you move the brake and gear arm on your mounting plates? Can you show pictures of what you did?

[manjisann]

Nice look! I like how you left the wheels unpainted.

Brandon

[Buber]

Unpainted wheels are standard on the european Z.. So you just kepp them clean.. And they are mounted with pressed dents "inward", if you know what I mean...

[scunny]

I left the brake and gear linkages as they were, soon as I can find my camera plug I'll post the pics

[scunny]

hopefully these pics will work

[cafeconleche]

what happened tp the cx500 tank? im interested if you want to get rid of it.

[madsen5]

Hey Scunny - thanks for the pictures. That looks fine with the cut down standart brackets, it lightens the hole thing up. I feel like I need to get my feet back a bit further though. May be I'll find the money for an aftermarket rearset sometime.

Cafeconleche I still have the CX500 tank on my bike. I think you are looking at the pictures of Scunnys bike. I found the tank on German Ebay and I only paid 60 dollars for it. There's lots of them out there. Also if I had more money I would probably use something else like an aluminium or proper racing tank that fits the frame a little better.

I hope I will find the time to remove the rear fender/airbox this week. I'm going to replace it with the K&N pods that you can see in the picture below. This probably means that I have to re jet the carbs as well. Right now the main jets are the standart size 95. Any of you guys have any idea what I should go for? I have the CV carbs with no extra groves in the needle but should I shim them?

Any help with this is greatly appreciated.

[sangyo soichiro]

I love your tail light.  But Denmark need to do something about those huge license plates.

[Edit:]  I love the rest of the bike too.  Especially the tail.   

[greenjeans]

That's too nice to be a "rat" cafe.....  looks like it's all busines.  Pipes really look mean.
I dig it, looks fast sitting still.

[madsen5]

So tonight I had the chance to remove the airbox and rear fender and put on the K&N filters. The original jets were 92's so i followed the advice of K&N to up them by 15%. 15% up is 106 but the closest I could find was 108.

Putting everything back together was a real struggle. I didn't expect that. These filter are supposed to fit the bike. I got the filters on but the carbs are not level and the filters are hitting the frame. I really hate stuff like that.

Next up was the test ride. From 1/4 throttle and up its bogging out. Its much better with the choke on which tells me that its lean. So what do you think I should do next? Up the jets even more or maybe try to shim the needles?

You can see in the picture how bad the fit is. Ideas?

[cb650]

With the cv carbs the stock jet should have been at least a 118.   The haynes manual lists the single cam 650's untill 84.  Try the 650 site.  Half the guys there are not US but is is a slow site.       http://www.hondacb650.com

[madsen5]

It seems that nothing about these carbs is like the book. The jets are different from from what I can find in the Haynes book also the needles are different, mine are labeled 80B. I can't find that in the book either. The carbs are labeled VB54D which also I cannot find in the book. The closest is the UK SC model which have VB54E carbs with 95 jets and 12S needles.

Unless someone knows more about these carbs I guess I will have to assume they were stock and just go from there. I will try and get some jets in the 120-130 range today.

About the fit of the filters I guess that maybe the VB44 range of carbs on the US models takes up less space than the VB54 range of carbs on the European models and that's why I don't have enough room. I don't know.

I will ask the question on the hondacb650 forum as well, thanks for the hint on that, maybe someone there knows more about it.

[madsen5]

So I just put in the 125 jets and the result is...... no real difference!?!

So I'm up to size 125 from size 92 and still very lean, doesn't that sound a little strange?

[cb650]

Something might still be pluged up in the carbs.    Dont know what else to say except good luck.  It takes some doing to figure out jets.

[madsen5]

I decided that I cannot live with the airfilters and carbs not fitting correctly in the frame. Also the carbs I have are not in a very good condition. I read Soos's thread about the kawasaki GPZ 600 carbs beeing a perfect replacement. Besides being a better carb with more adjustment options they are about 3 cm shorter so I think that will solve the problem with the airfilters.

Yesterday I found a set of GPZ carbs on Ebay and got them today for 20 GBP (30 dollars). The guy will mail them tomorrow and hopefully I will get them monday or tuesday. It will be really interesting to see how this goes.

[madsen5]

Monday I got back from Greece - warm weather, fabulous lamb, great scenery. Oh well - to the point.

When I got back the Ninja carbs had arrived. They are not as good looking as I had hoped for, but complete and functional. I spend the last couple of evenings tearing them apart, soaking, cleaning, boiling jets and putting everything back together.

It looks as if they have been run without a filter in a dirty environment. The slides were very dirty on the inlet side, but I got them cleaned up so they don't stick.

Best thing is the K&N filters fit the new carbs fine. If my measurements are correct they will fit the frame no problem.

Hope I get the chance to fit them tomorrow... I can then spend the night dreaming the bike will go perfectly with them.

Check out the pics!!!

[madsen5]

more pics...

[Hush]

You are gonna be in so much touble with someone when they see you have used the stove and their best pots for boiling bike bits ha ha, love it, can't wait to find out if the Kwaka carbs work for you.

[Nicolai]

Nice bike...

I'm also a sohc4 member from denmark but I will keep it in English so everybody can read along 

Where did you buy your seat (or just the back end of the seat)? I love the look of it I might buy it for my CB500 cafe.

And for whoever that mentioned the big numberplates in denmark....that we can live with, but a 180% tax on cars and bikes is much harder to accept

[madsen5]

You are gonna be in so much touble with someone when they see you have used the stove and their best pots for boiling bike bits ha ha, love it, can't wait to find out if the Kwaka carbs work for you.

If we are going to have anything to eat in this house I will have to make it. Actually I prefer it this way. My girlfriend cleans the kitchen afterwards and does the laundry instead. Anyway the stowe and pots are 'mine'. ;o) Put she didn't like the smell of gasoline from the carb parts for the two days they were lying in the kitchen.

Where did you buy your seat (or just the back end of the seat)? I love the look of it I might buy it for my CB500 cafe.

It's a seat cowl from a Suzuki GSXR600 and I got it of german Ebay. It cost me around 15 euro.

[madsen5]

The new carbs are on and working!!!!

It was so easy to put them on and they seem to have been made to fit this bike with this filter.
At first it was very lean but I have upped the main jets from 108's to 125's. The needles are the original non-adjustable items (i have checked all carb parts against the kwaki shop-manual). This means that the adjustable needles Soos have in his carbs must be part of a jet-kit or something. Anyway - I shimmed the needles with washers lifting them about 4,5 mm.

It feels about right now but I don't have enough experience to tell what changes to make from here.

All in all I consider the new carbs a big success well worth the effort.

I'll snap a few pictures asap.

[Nicolai]

Are you able to fit two people on that seat?

[madsen5]

Most of today was spent with the family but this evening I got away for a short ride. I belive it runs even better now than with the original carbs and air box. And it looks so much better without the air box. Next project is to hide the battery somewhere to completely free the triangle behind the carbs. I snapped a single picture of the setup just now. Its a flash picture taken in the dark but i guess you can see how well everything fits. I'm just so thrilled about this!

Nicolai - I made the seat for one person only but you can easily make it a bit longer. I'm putting rearsets on it later so mine will be a solo ride.

[madsen5]

By the way - I just won an Ebay auction for a rearset. It was 41 GBP which is about 50 dollars. Its being mailed from Australia so I will have to wait around 10 days for it. Here's the Ebay image...

[The_Crippler]

Is that carb switch something only works on the CB650z in '83, or does it work on others like an '80 CB650C?

[daewon774]

By the way - I just won an Ebay auction for a rearset. It was 41 GBP which is about 50 dollars. Its being mailed from Australia so I will have to wait around 10 days for it. Here's the Ebay image...

Nice thread.  I just went through the entire read.  Great idea on the tank and especially the GSXR seat cowl.   I might go the same route and use the cowl on my cafe project as well. 

How hard was it to mount the tank from the cx500?  Was it just brackets that needed to be fabricated? 
I just picked up a 81' CB650.  The stock tank is just horrible.  I've been looking for options, lol.   

BTW, any updates on your progress?

[madsen5]

Hi there

@The_Crippler - Try doing a search on the forum for Ninja carbs. You will find a few threads explaining exactly how things work with the Ninja carbs.

@daewon774 - It was real easy to use the CX500 tank. You just need to fabricate some very simple brackets to move the forward mounting rubbers down and forward a bit. In the back I used a 1" length of tube to lift the end a bit. That's it.

No progress in the last couple of months. I'm building a new kitchen, which includes new insulation, concrete slab, ceiling, plumbing, electricity, tearing down a few walls etc. So that will keep me busy for a while. Hope to be back on the project in a couple of months.

Thanks for your interest

/Mads