1974 CB360 - first bike/build

I grabbed the float height tool specs from Trek and printed out a few - they came out perfectly. I printed 19.5, 20.5, and a 21.5 heights.


 
You won't need 21.5 unless your 6,000ft or more up or use E85.
21mm is my recommended float height for E10 or modified carbs although 20.5mm is very slightly richer everywhere if you need it due to exhaust length/modifications
 
huck_finn said:
I grabbed the float height tool specs from Trek and printed out a few - they came out perfectly. I printed 19.5, 20.5, and a 21.5 heights.



Those look familiar! ;)
 
Here are a few shots of the corrosion I was talking about. The other carb is in good shape, but I am not sure if I will be chasing my tail trying to get this one working the way it should.








 
No need to worry about the corrosion as long as nothing is 'pin-holed' I've worked on much worse that worked fine
 
If nothing else, just Be careful tightening the jets into those corroded castings. A Yamaha I recently sold had similar corrosion and the main jet had been over tightened and cracked the casting.


Sent from my iPhone using DO THE TON
 
Pretty sure Mikuni use a 'stock' zinc based alloy which does seem to be more brittle than the Kei-Hin stuff.?
I've done XS400's with less corrosion but more damage plus a few XS650's and Kawasaki's have needed at least 1 'new ' carb.
Maybe Kei-Hin use a different 'proprietary' zinc alloy? It does seem more 'malleable' when I've been doing carb mods compared to the Mikuni's I've done (only GS and GSX-F air / oil cooled range, everything else is 'too new' ;D )
 
I put the new friction plates & springs on last night (after soaking the plates in oil for 24hr). I also bolted on the new stator. There isn't a whole lot more to do with the engine right now since I am not going to bore it out. Anything that needed replacing/fixing was done while still on the frame.

My frame and a few other pieces are in the shop for paint - having the paint/bodywork program at the community college where I work do it for me. All I needed to do was pay for the paint. They do a good job, but you just can't be in a hurry to get things back.

I think I remember seeing some pictures (can't find via search) on how to dremel out the metal oil guide (right crankcase) to help with oil flow. Do I need to watch out for anything if I give it a go?
 
Just check there is enough support for the spring inside it and make sure you don't lose spring tension on retaining clip when it's time to re-assemble.
 
Printed out a test plate to make sure my measurements were good for my air box/filter. I was thinking of creating a design that is similar exactly like <a href="https://cognitomoto.com/products/cb750-air-intake-box-sohc-and-dohc?variant=11585137601">ones I have seen for 750's</a>.

Where the plate mates up with the intake is a really snug fit, but I have no idea if it will leak any air. I will have to wait until I get everything back together. Frame will be back from paint next week.

If anyone has done something similar for their 360, I would love to hear how it turned out.








 
That's kinda cute.
You really want a radius on edge though, 3/8" seems to be about minimum for good flow. ( there are other radii and angles for max flow rate)
Sharp edge acts as a restrictor at high airflow
 
crazypj said:
That's kinda cute.
You really want a radius on edge though, 3/8" seems to be about minimum for good flow. ( there are other radii and angles for max flow rate)
Sharp edge acts as a restrictor at high airflow

When you are referring to the edge, which edge do you mean? My thought behind going this route is to reduce the amount of space the air box takes up, while maintaining the same amount of filter surface area.


Sent from my iPhone using DO THE TON
 
The edge where tube meets plate. As your 3D printing it, it should be simple enough to make the 'tube' 7 degree internal angle to carb mouth and radius onto plate. Make one of those and I'll try it (or send file and I'll get it printed)
 
Someone on here has done this very setup in the past. (I thought it was bucky685, but I cant find anything about it.)
He found a "ready made" filter to fit his custom base perfectly. Volkswagen Maybe???

I will keep searching.
 
Yup. Radius the point where the intake tract meets open (or airbox) air. A raise bellmouth that sits inside the airbox is effective.
 
Yep, that would be even better but way more difficult to print. What filament are you using as temps can easily get around 200f
 
I am not sure what the standard filament is, but I do know they have ABS plastic, carbon fiber, kevlar, and onyx. The onyx produces the most finished look out of them all. The carbon fiber and kevlar filaments use nylon as a binder.

I haven't had a chance to work on the design in a while - work has gotten busy and I haven't been taking lunch to head down to the lab.

I did get my frame back from paint. Everything I got back looks good, with the exception of the rear brake cover, which came out with a run on it. The kid working on everything repainted it three times, but just couldn't get it to come out. I suppose I got what I paid for. More than anything I am glad rust won't be a concern for the foreseeable future.









When I get back from visiting in-laws I will need to put on the new steering bearings before reassembling, and taking final measurements for the air filter and seat pan.
 
Back
Top Bottom