1974 CB360 Engine Troubles (I think)

crazypj said:
You now need to vacuum sync carbs and run it for at least 200 miles.

So I followed this video when syncing my carbs https://www.youtube.com/watch?v=TAhhMMnfN7Q Is this not vacuum syncing the carbs?

And I'll definitely be riding now that she works! Just gotta wait for the rain to pass :mad: Thanks for the tip on checking the oil level, I'll be keeping a close eye on that.

See you all in 200 miles 8)
 
You got it. 8) Now you can dial in Air/Fuel mix adjustment to its happy place.
 
Back with an update! (Not a good one unfortunately )

One day while I was starting my bike up I heard something like air seeping through the right carb, so I decided to take it off and check to diaphragm, which has a few tears in it )

Since this is just in the carb, the only thing I would need to redo is the carb sync right? Now it's just time to wait for the diagpgram to come in
 
Stink! a torn diaphragm shouldnt effect sync. But its an easy thing to check.

Where is the new diaphragm coming from?

Also, its best to run pure gas, as ethanol is a powerful solvent it will dry diaphragms and o-rings.

You can find a source here.
https://www.pure-gas.org
 
The diaphragm was super hard to find, the only place I could find one (aftermarket) was from CMC.

And dang the closest gas station is about 50 miles in ever direction (living in Chicago) :(

What issue would a torn diaphragm cause then?
 
When the diaphragm is torn, the slide wont rise. So, she will go lean in higher rpms. Wont effect idle or lower rpm running at all.
for pure gas Im in the same boat. Down here in Champaign Illinois. (3 hours south of you)
Its about a 1.5 hour round trip for me to get pure gas. So I buy 10-15 gallons at a time. :mad:
Which reminds me its time for me to make the run.

Some guys claim to have good luck w aftermarket, I tried the JBM diaphragms once. They went directly into the trash can. $40 for the pair wasted. My 360 wasnt ridable with them. http://jbmindustries.com/Keihin_diaphragm.html
They were too soft and would allow the slides to rise to quickly. Making her run crazy rich around 2500 rpm.

I picked up new OEM Honda slides w diaphragms and springs. (Kit #7 at local Honda dealer). Runs like a champ now. 8)
I couldnt be happier w them. http://shop.sportlandmotorsports.com/OEMpartfinder.htm#/Honda/CB360TA_(76)_MOTORCYCLE,_JPN,_VIN%23_CB360-2200001/CARBURETOR/CB360T-76-JPN-A/2Y133871AE13387116A
 
trek97 said:
Down here in Champaign Illinois. (3 hours south of you)
Try a 1.5 hour drive (I drive down there alot to visit my gf at uofi)

Well hopefully the diaphragm I bought will work out, don't feel like spending $100 for the OEM one lol

So could that have been causing the smoke from the one side at higher rpms?
 
Heck we will have to get together sometime. I work in the University Elevator shop.
Its about 3 hours from my house to O'hare. I dont exactly live in Champaign but close enough.

I think maybe yes, ( Although, I dont recall mine smoking when it tore a diaphragm) its possible to think a torn diaphragm could cause some smoke at higher rpm.
Since she couldnt draw enough air through the carb. (slide being down) She may have been sucking air from someplace oily.
Vacuum is a very powerful thing.

Yeah, I noticed the price. :eek: They have gone up substantially since I bought mine. thinking I paid $140 for pair.
Fingers crossed. Hopefully the CMC diaphragm is just the ticket for you. :)
 
trek97 said:
Heck we will have to get together sometime. I work in the University Elevator shop.
Its about 3 hours from my house to O'hare. I dont exactly live in Champaign but close enough.

That would be cool! Especially since you're the one why pretty fixed my bike up ;D
And yeah normally its about a 2-3 hour drive down there, but with the right speed and an open road its easy to cut that time in half 8)

So most of what I've been seeing is that smoke is caused by bad rings/valves, but I've consistently been getting ~160 on my compression tests. Could you have good compression and still have bad rings/valves?
 
Did you change the blinker relay to electronic when you changed to LED bulbs?
 
Which bulb did you replace? Front or rear?
Those LEDs are single filament bulbs.
They will only work in the front blinkers, not rear.
For rear you need dual filament.
If you replace them all you will need to add diodes to work w the single indicator on gauge. (I get diodes from Sonrier at sparckmoto.com)

and as miller stated an electronic flasher.

When do you expect to have the new diaphragms installed?
 
trek97 said:
Which bulb did you replace? Front or rear?
Those LEDs are single filament bulbs.
They will only work in the front blinkers, not rear.

Well the bike has aftermarket turning signals, and they are all single filament. I plan on purchasing the electronic flasher from Sonrier, but if I don't have the gauge indicator I don't need the diodes right?

Will the electronic flasher work with the cb360? Or is there anything I would need? (I already updated the regulator/rectifier)

Also, diaphragm comes in today
 
If you have a stock type flasher the indicators won't flash unless you fit a load resistor.
Cheaper and easier to get relay suitable for LED.
Single LED may not work on front if it has double contacts for running lights?
You won't need diodes if you don't have warning light
 
The flasher he sells will plug right in. If it still doesnt work w new flasher, swap the two wires on the flasher connectors.
No, if you dont have a gauge indicator you wont need any diodes.

BTW, are you only replacing the one diaphragm? If so, I might think tuning the carbs could get a little wonky.
I wouldnt be surprised if the other diaphragm is soon to follow.

A sure sign of a torn diaphragm is one white plug and the other dark.
 
I only replaced one diaphragm, I didn't want to order 2 because I wanted to know if this aftermarket one would work.

But, as usually, I noticed another problem I put clear fuel lines on the bike, and I was going to warm the bike up before I did the carb sync, and saw that no fuel was going to the right carb. I took it out for a ride still, hoping something was just stuck, and after my ride fuel was in the tube, just none of it was going into the carb is this going to require the carbs to rebuilt?
 
The float may be stuck closed. Needing cleaned/cleared of debris.
Do you have inline filters? I never had any luck w them. I just count on the tap screens. But my tank is pretty clean.
I also keep a small magnet in tap bowl to help catch any rusty particles. It works well.
 
Well I did adjust the floats since they were about 6mm off. They werent stuck when I was adjusting them, could they have gotten stuck when I attached the bowl?

I'm having a hard time understanding where the fuel feeds from the tube into the carb, I dont see any paths from the fuel line.

And no, I dont have inline filters. Fuel line goes straight from the pet cock to the carbs.
 
I've done a load of 360 carbs, 6mm seems a lot to adjust but I have seen tem with very low float levels. Are you set at 19mm or 21mm?
 
You said the line had no fuel in it when you started, but it was full when you got back? That's normal. The float doesn't open until you start to drain it while running. If you have the lines off, or just installed them, then they'll stay empty until you use some fuel. If no fuel was going into the carb, then the tube would never fill up.
 
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