Topic: Patina Hyena - 550/650 674cc Hybrid Cafe Build

[SOHC4 Cafe Racer Fan]

I like the metal fab work. The upholstery is very impressive - you may try to tighten some of the corners so it takes in some of the small slack areas. Better than anything I could do!!

Thanks! Yeah I know it's a little baggy in some areas. I've upholstered things before but with less "shape" than this. My old seat was pretty plain. A learning experience for sure.

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1978 Honda CB550K

I hope that didn't come off the wrong way.  The form of the seat is excellent.

No, not at all! Thanks for the compliment!


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1978 Honda CB550K

Excellent.  I really appreciate the work that you put into that seat. 

[arogers88]

Seat looks killer... Have you been enjoying this great CT riding weather?

[DaveBarbier]

Seat looks killer... Have you been enjoying this great CT riding weather?

Definitely, today was pretty perfect. Open jacket with t-shirt, very comfortable.

Thanks man!


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1978 Honda CB550K

[DaveBarbier]

From riding around lately I've noticed that my bike will often stall when coming to a quick stop or a normal stop that's down hill. All other stops don't make the bike stall. I'm guessing my float height is a little low (momentum sloshing the fuel in the bowls forwards too much enriching the pilot circuit). With the clear tube method my bowls are all the same. About 4mm below gasket surface.


Should I raise the level another mm or so? Could something else be causing this? Doesn't matter if the motor is hot or cold, and I have a full tank of fuel.


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1978 Honda CB550K

[Tews19]

I had low floats. Adjusted last night but even being lower than that I never had the bike stall. I'm at about 200 miles since the build was completed.  Maybe your idle is to low?

[calj737]

My opinion: you don't want the fuel ANY higher than that. In fact, I'd probably lower it.

[DaveBarbier]

I had low floats. Adjusted last night but even being lower than that I never had the bike stall. I'm at about 200 miles since the build was completed.  Maybe your idle is to low?

RPM is about 11-1200. I had a stalling issue when I'd come to stops randomly but I raised it and it isn't a problem anymore. Maybe these problems are related and me raising the idle is just masking it but I don't know.

My opinion: you don't want the fuel ANY higher than that. In fact, I'd probably lower it.

Still could be a mixture issue or a fuel level issue I guess. Maybe I'll try lowering fuel level a millimeter or so.


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1978 Honda CB550K

[Tews19]

What size slow jets? Also maybe do only 1 turn out on the air mixture screw?

[DaveBarbier]

What size slow jets? Also maybe do only 1 turn out on the air mixture screw?

IMS is 1 turn out. Slow jets are 45. Stock is 42. Also, they're Keyster jets because the PO drill out the originals. That could be an issue but it doesn't feel or smell rich and plugs aren't black, they seem pretty good. I'm also a novice at diagnosing lean/rich conditions, haha.


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1978 Honda CB550K

[seanbarney41]

My opinion: you don't want the fuel ANY higher than that. In fact, I'd probably lower it.

+1, that is too high...from your pic, looks like fuel level is right at the gasket

[DaveBarbier]

My opinion: you don't want the fuel ANY higher than that. In fact, I'd probably lower it.

+1, that is too high...from your pic, looks like fuel level is right at the gasket

Really? To me the picture seems like it's below the seam. Anyway, I'm out with the bike right now and am measuring all levels again. They are all exactly 3mm below the seam. I will lower the level (raise the float height) by 1mm across the board. Giving me 4mm from the seam.
After a test I'll come back with results.


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1978 Honda CB550K

[seanbarney41]

I guess I dunno...could be a tricky angle or I am not familiar with those carbs.  Anyway, I would definitely try a lower level before higher.  That is the benefit of the clear tube method...gives you a visual guide to what is actually going on inside the carb...but this also makes me miss working on Holley 4 barrels...external  screwdriver float adjustment with a sight glass/plug would really kick ass on these!

[calj737]

...external  screwdriver float adjustment with a sight glass/plug would really kick ass on these!

say that again!

[seanbarney41]

...external  screwdriver float adjustment with a sight glass/plug would really kick ass on these!

say that again!

easy to do on the internet

[DaveBarbier]

I guess I dunno...could be a tricky angle or I am not familiar with those carbs.  Anyway, I would definitely try a lower level before higher.  That is the benefit of the clear tube method...gives you a visual guide to what is actually going on inside the carb...but this also makes me miss working on Holley 4 barrels...external  screwdriver float adjustment with a sight glass/plug would really kick ass on these!

Yeah after you guys said to lower it I can see what you mean after looking around on other posts. And besides, if I suspected the pilot circuit being enriched by the forward slosh of a hard braking bike, the raising of the fuel level in the bowls would be counterintuitive. Lowering would make much more sense.

And as far as the sight glass and external float adjustment...my god, that would be so helpful. But then I wouldn't become a pro at removing and installing my carb rack...


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1978 Honda CB550K

[DaveBarbier]

Ok, now they're all like this, which is exactly 4mm from seam. Would you guys still say it's too high or is this satisfactory?

Edit: a picture would help...


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1978 Honda CB550K

[calj737]

Certainly better IMO

[seanbarney41]

That's right where I would put them...real and only test is how it runs now...

As far as I know the 3-4mm below the bowl gasket spec was strictly only for early cb750 carbs, although I, and many other have used it successfully on many other carb sets...even Mikuni's

[DaveBarbier]

That's right where I would put them...real and only test is how it runs now...

True, but considering it ran fine before except the stalling when coming to a quick stop or a stop down hill. That problem might not even be fuel level related. We'll see. Thanks guys


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1978 Honda CB550K

[DaveBarbier]

Been doing some tests and it seems like that solved the issue. I've been doing some hard stops down hill and it won't stall. Thanks guys, I'm going to keep an eye on it. Now to track down a buzzing between 6500-7250 rpm. Probably cables vibrating against the headlight bucket but when I play with them it doesn't help, oh well. Minor problem.


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1978 Honda CB550K

[Tews19]

Check the fender. Sometimes they become loose from the rivets. Nothing jb weld can't fix under the fender. I had this problem one time .

[DaveBarbier]

Now on to another idea. There's been a few posts I've been following of people getting 650 cams or big bore kits and such. I've been entertaining the idea of getting a full 650 motor, tear it down and rebuild it, maybe get a .5mm overbore or something or 1mm, still have to do more research. But then put it in this winter.

I found an '82 650 about an hour and a half from me.
"hasn't been started in about 5 years but ran before parked. excellent parts bike. Good engine/tranny."

http://images.craigslist.org/00Q0Q_ijWgIu7qOAP_600x450.jpg
http://images.craigslist.org/00t0t_8UYX6RkddG5_600x450.jpg
http://images.craigslist.org/00n0n_jr2Mq0WPdgx_600x450.jpg

You guys think this could be an option? He wants $430 for it.


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1978 Honda CB550K

[DaveBarbier]

Check the fender. Sometimes they become loose from the rivets. Nothing jb weld can't fix under the fender. I had this problem one time .

Thanks Tews, I chopped it earlier and drilled out the rivets and replaced with nuts and bolts. I'll make sure they're tight.


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1978 Honda CB550K

[SOHC4 Cafe Racer Fan]

$430 isn't bad for an entire bike, especially if you can sell the parts you don't need to pay for the motor.

Check out Dynoman's 674cc kit.  It works with stock 650 sleeves. 

[DaveBarbier]

$430 isn't bad for an entire bike, especially if you can sell the parts you don't need to pay for the motor.

Check out Dynoman's 674cc kit.  It works with stock 650 sleeves.

That's what I was thinking. I wish it was closer so I'd feel less invested if I went there. Is it frowned upon to go there and drop the pan or verify that it turns over? No kick start so I'd have to remove the points cover and bring a wrench or something. Anything else I should check? If/when I go to check it out?

Thanks, I'll definitely check out that 674cc kit.


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1978 Honda CB550K