Topic: Bike stored for 29 years - tips welcomed on oil flush and prep before startup

[lockeed]

Emulsion tu ABOVE the main jets?   

[b52bombardier1]

Yes, above each main jet.  I think you will get a better idea looking at the tube above #37 in the picture here:

http://www.cmsnl.com/honda-cb750k6-four-usa_model14380/partslist/E19.html#results

  Not sure exactly which "K" number bike you have but the link above is to a K6 USA bike.

Rick

[lockeed]

Yes of course, sorry I misunderstood while I was reading your comment on my phone...

These where properly cleaned.

Side note, I did take off the carbs this afternoon and cleaned the slow jets. They were if fact dirty. I also caught a mistake I did; while cleaning carb #1, I took out the needle and throttle valve to clean each of them and for some reason, I reinstalled #1 incorrectly. On the air box side, the valve are beveled, I put that bevel the other way around on #1... Don't ask me why. Now everything looks good and I know the accel pump works, I sprayed some gaz in my eyes   

Should be able to try it on tomorrow, should make for a much smoother engine!  Tips welcomed here, would it hurt if I didn't put on the air box just for a couple engine run tomorrow?

[ekpent]

I start them up all the time without an airbox when I am working on them.May run leaner but should do no damage.

[lockeed]

Thank you sir - we'll see what happens.

[lockeed]

Thanks to all for your inputs - carbs went back in the bike today- feels like 1977 all over again compared to last Friday Very smooth now.

Motor feels much much better, but its not perfect, here's why and maybe you guys can chime in:

1) Says in the manual the bike should idle @ 1K rpm +/-, mine idles great at 1400rpm (tach reading) and this is with the air box out. If I go lower and drop it at 1.1 or 1.2K it tends to drop in RPM and stall after maybe 10 seconds. Other than that, engine runs smooth at 1.4 to 1.5K idle.

2) Twisting the throttle quickly from idle, it'll stall for a second before it picks up. If I do it quickly but more gradually, it seems to work just fine. No backfire anymore though and engine feels strong.

Tips welcomed.   

[Desert-SOHC]

My K8 was the same way and I went 1/4 more on the air/idle screws and it calmed down a little more.  I can do 1K at idle but nothin lower than that.

[Stev-o]

I set my idle by ear not a 40 year old tach that is not super accurate. 

[Don R]

 Are the accelerator pump nozzles working?

[ekpent]

 Get it running as best as you can now but the real test will be when you drive it out on the road under a load. That will be the big test.

[lockeed]

Yes they do, accel pump seems to work great.

And I agree, the big test will be on the road, noting like a good ride.

[SOHC4 Cafe Racer Fan]

I ultimately found the culprit = looks like insulation from the exhaust... don't know how that could bundle up like that and clog the exhaust, maybe mice? Anyway, I took it off, so that's solved.

That looks like nesting material for a small mouse. 

[Mr. Mike]

Good progress.
Another "thing" about my 78 is, it seems to take a about a mile or two of riding before the idle settles down or settles up to about 1150rpm. It seems happiest there as anything near 1k tends to welcome a stall and I hate revving at a stop light just to keep it alive. But, like I said, after a short distance, no worries.
If it persists to cough at throttle on, you may yet have to get to the timing, points cleaned/gapped and get carbs sync'd up.
And that clutch clatter noise you'll hear...normal. It diminishes a tad when the clutch is pulled in.
Let us know how it idles/runs when good and warmed up.
Oh...you do have a fresh set of plugs in right?

[lockeed]

Yup, plugs are new. What's left on the to do list are:

-Carb Sync
-Idle screw adjustment
-Last oil change + new filter
-Clean and inspect points, replace if needed
-Replace air box to carburetor boots
-Repair front brakes. Brake fluid had leaked over time, ordered a set of diaphragm and rings. We'll see what happen.

[Stev-o]

Still not finished with that last list?!

[PeWe]

Just faaar idup an take off.

 The first 750 I got running after 25 years of no bike had a huge bog, I got mad and cranked it wide open, when it decided to go I was not ready and for 100 feet or so I was hanging on for dear life. I got a new respect for old 750's, drag strip launch, can't let off cause I'm hanging on for dear life, feet fell off the pegs, sliding back on a slick seat, yeow!

That's riding, cowboy style!! Typical CB750..it takes a while get used to how to twist the throttle!

[Phinn]

That looks like nesting material for a small mouse.

My son named my bike "Mouse" for that very reason. It had a nest in the airbox.