Huge thanks Daves79x: It's the little things ^.^

[RJ CB650]

Massive thanks to Daves79x

It started with asking about a carburetor issue. Here is a link to the posting in the carbs section:

viewtopic.php?f=20&t=9093

To short note it, I had a bad stutter, couldn't tune it in, was behaving as though it was super lean.

Dave made mention about how cbxes are unique in their ability to idle on 5 cylinders, but that was sort of past and we went on to talk about carburetors. Well, I had thought jokingly that it could run on half the engine so decided to do the check to see if all cylinders were warming equally.

Turned out 1 and 3 were stone cold.

Okay, carb issue, what can it be. Well, I decided to check spark. Yup, spark at the wires. I had to go out so didn't pull the plug to check for lean/rich/etc. or make sure the plug itself was getting spark.

Get home, and okay, lets check the spark on number one.... hrm.... that came out very easy. Oh look, the crush washer gasket wasn't even compressed! Boy is that plug clean, is like new! Number 3 had been firing in past, but in my runnings, it just got a nice, wet coating of fuel.

Every plug, was only in hand tight.

I am going to point out, every used vehicle I have ever gotten, I always buy new plugs. But the CBX had clean and new NGK R high grade plugs so I didn't concern myself with pulling them out. I was pulling carbs off anyways, so did my checks and cylinder fogger treatment into it from the intake ports. This is the only used vehicle ever that I didn't touch the plugs by default XD

So, tightened plugs, got it running on all six cylinders, got the mix re-set properly and did some run/adjust/repeats for a while. Clutch on the CBX is definitely a trick to get dialed in compared to my 450 or 650. Sat a while so needed re-adjust as it got itself deglazed, etc. It had a slight stutter at 3000, but that went away in short order. Probably a little buildup or some slight grunge in a passage that cleaned out. Will find out when I get a proper full tank and some fuel system cleaner through it.

So on final note and summation:

I spent three days getting it tuned in without addressing the issue. Daves79x, if you hadn't made comment about "Make sure it is running on all six" It might have been another three days til I got to checking the plugs, and most likely resulted in me pulling the carbs off again and recleaning them and after I ripped my hair out when that didn't solve the issue.

[RJ CB650]

Thinking now. I was right on my running super lean theory and/or having a vacuum leak. I guess loose spark plugs would constitute a vacuum leak...

[daves79x]

Glad you're getting it sorted.

Dave