CB360 - cleaned the carbs, it revs to redline and then dies

I have been trying to nail down why the left cylinder was running cool compared to the right. So I did the following:

- Set the cam chain tension
- Adjusted the valve clearances
- Adjusted the timing

At this point it started, idled for a bit at around 1200 RPM, but then died. I kicked it over again and it wouldn't even idle - just died no matter how much I feathered the throttle.

This afternoon I pulled the carbs, disassembled, cleaned (they weren't too dirty), put them back together using rebuild kits from Common-Motor, did my best to bench sync, and threw them back on.

Sprayed in a little starter fluid, and as soon as I kicked it over it went straight to redline without me throttling - and then it died. Tried it one more time and I got the same results. There was a slight tear in the right carb's diaphragm, but that wasn't the cylinder that was giving me trouble - so I put it back together just to see what I would get (getting good rise and fall when I blew through the carb).

I should have mentioned that before I set the cam chain, valves, and timing the left cylinder wasn't firing at all. It was running (although briefly) when I had it at idle.

Well it wont run right with a tear in the diaphragm. Are you running pods or stock air box? Float heights set? Make sure the pilot holes are clear, they are the 3 tiny holes under the throttle plate.

You have strong spark on both sides, and your timing is spot on? Don't use starter fluid. It should start right up with a few kicks if you have it set up correctly.

Once you get it running, you absolutely need to vacuum sync. It'll run on one cylinder and/or like complete crap if your even the smallest bit out.


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advCo said:

Well it wont run right with a tear in the diaphragm. Are you running pods or stock air box? Float heights set? Make sure the pilot holes are clear, they are the 3 tiny holes under the throttle plate.

You have strong spark on both sides, and your timing is spot on? Don't use starter fluid. It should start right up with a few kicks if you have it set up correctly.

Once you get it running, you absolutely need to vacuum sync. It'll run on one cylinder and/or like complete crap if your even the smallest bit out.


Sent from my iPhone using DO THE TON

Click to expand...

Thanks for the reply - my new diaphragm should be here today, along with an ignition rebuild kit. I am running pods - bike didn't have any thing in terms of filters when I bought it. I will check the timing again once the ignition kit is on there. But the float height for both carbs is between 17.0 & 17.4. I saw that some people suggest setting them closer to 16/16.5, but when I did they bottomed out (didn't have any play/bounce back).

I did notice a few small notches on the carb's butterflies (engine intake side). Is this something that I need to be concerned about? I did my best to get shots of it (if you right click on them to open in a new tab, you can really get zoomed in to see what I am referring to).

<img src="http://www.midnitegin.com/wp-content/uploads/2016/11/open.jpg" alt="" class="bbc_img">

<img src="http://www.midnitegin.com/wp-content/uploads/2016/11/closed.jpg" alt="" class="bbc_img">

If you look at the picture with the butterflies open, the tiny holes that disappear when you close the throttle need to be clear. Those are the pilot holes. Use a needle to make sure they are clear.

Are you running cheap pods or UNI/K&N? The cheap pods need to be modified to work correctly, there is a post here somewhere about it.

The pods I am running are from Common-Motor ($30 for the pair). The main jets that are in the carbs right now are 100s - but I did grab a re-jetting kit from CM.

Appreciate the reply.