Topic: The only thing SCREAMING now is the bike on the highway!

[medic09]

Idle mix screw adjust.  It escapes my puny mind why there would be any advantage to starting with #2.

[upperlake04]

Yeah, mine too

[TwoTired]

For adjusting carb idle, the manual recommends starting with #2.  I know that's our index carb; but would it make much difference?  When I set the idle today, I started from one side and worked across.  Started at #4, actually.

Is this the Honda Shop Manual?  Pg 257?
My Honda Shop Manual doesn't specify any order for the pilot screw adjustment.
It does, kinda, under the "Synchronizing Carburetors" heading noting 1,3, & 4 being addressed.

I see no reason to adjust pilot screws in any order besides random, in which any sequence of numbers fit.

BTW, the 77-78 CB550 has the same arrangement as the 750 carbs, both with Sync and pilot screw.  The instruction read like they were written by the same person.

For rebuilding the carbs, they recommend not to remove the slow jet ("The slow jet must not be removed..."), since it is pressed in.  Hmmmm.....

Oh, they were just trying to impress the authorities that they had tamper proof carbs that wouldn't polute the environment by parts changers/ experimenters.

I don't think they ever offerred the pilot jets for sale on these carbs either.  Next highest subassembly, please. The whole carb.

Cheers,

[medic09]

The manual is the "Official Honda Shop Manual CB750 K8  CB750 F3" printed in Japan by Honda in Dec. '77.  This must be the last one, eh?  I think they sold these to owners who wanted a shop manual, as a part?  Pages 4-11, 4-12.

[medic09]

 

So, TT's idea of starting the bike with a little throttle has worked great.  Once started, it will warm up with a little throttle to keep it running till it gets there.  It takes a few minutes, but it's not so bad. Still have to idle kind of high (about 1200-1400) indicated on the bike's tach, but it sounds happy enough.

On the road, the engine works just great.  Maybe it could be a little better dialed in, but I sure can't tell anythings's lacking.    Gas mileage is reasonable.  Mid to high 30's if I cruise at 80+; mid 40s to almost 50 mpg if I tool along at 60+ on back roads.  Hit 110 mph escaping a maniac on the highway, and I wasn't even near redline.  Bike sounded happy as can be.  I'm pretty happy, too.   

Headed out in the dark this morning.  All the electrics work fine.  I didn't have gauge lights or a taillight when I started.  Now I've got a bike I can get on and go.  Temps were in the mid 30s, and there was no problem starting and warming up.  When temps are below freezing it takes a bit more to warm up, but TTs advice gets it going.

Brake service probably in the foreseeable future.

Thanks again to all of you for talking me through all the steps along the way.  Lloyd, I especially appreciate your analytical tutoring.  I hope to work on my Triumph later this year.  Do you tutor on British bikes, too?   

[TwoTired]

Glad it's all working out for you.  And, congratulations on work well done.  If there is no one local to pat your back, consider this the internet equivalent.  Your bike wouldn't be running this well without you.

Had a 62 BSA 650 non-unit twin in 72 when I was still a young pup.  Wish I could have kept it.  Had it running pretty good when I sold it off, having brought it back from the basket case it was.  Even Brit bikes comply with the laws of physics...mostly.  Haven't worked on a brit bike since, though.  You could post questions in the "other bikes" forum.  PM me if I don't notice it, as I don't alway peruse there.

Cheers,

[mrbreeze]

Glad to hear you're all sorted out there medic..........damn...those carbs sure work better with the floats right side up don't they?? Don't sweat it ......you aren't the first and won't be the last to do that!!!!

[medic09]

Glad to hear you're all sorted out there medic..........damn...those carbs sure work better with the floats right side up don't they?? Don't sweat it ......you aren't the first and won't be the last to do that!!!!

 

[andy750]

Well done Medic and Im sure many of us will be wanting to follow your lead! Enjoy the ride 

cheers
Andy

[gregimotis]

Fantastic thread all the way through.



Was especially fun hearing the weather reports from medic and looking out the window to confirm.