Ross’ 1975 CB750

[Steve G.]

   The story of the CB750 Honda.

https://www.youtube.com/watch?v=s6SzJsHOR9o

[Galactica]

My BS side cover repair.  Drywall mesh and epoxy.

[Galactica]

As clean as it’s gonna get by me until the day when I pull the motor.

[Galactica]

One parts order from PartsNMore (Ontario) should arrive Monday.  Another order from Dave Silver Spares (Pennsylvania) might arrive end of next week but probably the week after.  It’s shipped via USPS and left yesterday. 

I leave on a motorcycle trip day after tomorrow.  Heading down the coast for four days (short days) then heading east and returning via the volcanoes. Eight day trip. 

But OMG, the exchange is f-ing brutal.  I went into the bank today to get $100USD cash.  It cost $140.13CDN. 

[Galactica]

So, there was a small package of parts from PartsNMore waiting when I got back from my motorcycle trip to Oregon.  I installed new spark plug caps.  Now I have good resistance through both ignition coils.  New spark plugs.  A bit of effort to install the new roller steering head bearings.  Had to grind out the upper head stock and sand off the lower steering stem.  Oil filter & o-rings.  Signal flasher.  And a bunch of of other stuff that has to wait until I get my order from Dave Silver Spares.  

Interesting when you order stuff from Dave Silver.  Some stuff is in the US warehouse, and some stuff is in the UK.  They ship the stuff from the UK to the US then ship the whole package here via USPS for $20.  Waiting for things like fork tubes, fork seals, aftermarket seat, tire rim tape (couldn’t get it at Bby Kaw), grips, and more.

Picked up tires (Shinko) and tubes at Bby Kawasaki today.  Manny offered to let me bring my wheels and tires in and get help and advise in spooning them on myself, now that things are slowing down in the shop.  

Set the carb float levels (they were way off) and did a bench sync.  Put in new side cover grommets (side covers slip on and off like butter).  

Done lots of other little stuff.  Cleaning and rough painting of black bits like the chain guard and triple trees, front rotor centre.  Rough and dirty cosmetic work.  Much of it may well get redone if and when I really tear it down.  

Probably a bunch of other sty I don’t remember just now.  But it’s coming along nicely.  My order from Dave Silver will hopefully arrive late this week.  Might be ready for start up in a couple of weeks.

[Galactica]

Dang!  Looks like the carbs have to come apart.

Figured I should check that the fuel tees were tee-ing and not leaking (I re-used the o-rings), and that the needles were needling.  Everything was going swimmingly.  Had the carbs clamped in the workmate with fuel source jury rigged.  When I went to drain the bowls, only #4 had fuel.  Took the bowls off and made sure the needles weren’t sticking.  Maybe they were.  Checked fuel flow with the bowls off and fuel flowed just fine.  Put the bowls back on.  No fuel in them.  Pretty sure the needles and floats are working fine.  Only thing I can think is that the vent passages are plugged.  I’ll take them apart again and vibrate in in the ultrasonic cleaner again.

Dang!

[Steve G.]

 Carbs, the new nemesis, with 10% ethanol our new reality.

[Galactica]

Took the carbs off the rack.  Soaked each one in acetone for an hour, blew them out, vibrated them for another hour, rinsed, blew em out.  I’ll reassemble the rack tomorrow and try a gasoline test again.

[Galactica]

It seems the needles are hanging up.  I’ve ordered new ones.

[kilowop]

I had the same sort of carb issues when redoing my '81-550 Suzuki.  Carbs were a REAL mess.  After several attempts and hours of work, I ended up ordering a good used set from the Salvage yard in Williams Lake.  Good Guy, and very helpful. Prompt service too. Bike runs OK now.

[Steve G.]

  Getting back to my years old rant, regarding fuel/carburetor management,,,,,now with minimum 5% corn maise, …..,,
 I will tell you that use of good gasoline and very careful with our 4-5.5 month off season storage, my Laverda, and my BMW Airhead have not had their carbs rebuilt, 32 + yrs. They seem to run fine, no leaks.
 

[magpie]

Regarding needles and seats, best to order Honda ones. In my experience non-OEM have leaked. I clean up the seats with Brasso and a Q-tip. It cleans and polishes them up nicely. So far no leaks. Cliff.

[Galactica]

Regarding needles and seats, best to order Honda ones. In my experience non-OEM have leaked. I clean up the seats with Brasso and a Q-tip. It cleans and polishes them up nicely. So far no leaks. Cliff.

I totally get what you’re saying about OEM needles and seats.  The problem I have isn’t that they’re leaking, although I have yet to determine that, it’s that they don’t seem to unseat once the bowls are installed. 

[Galactica]

I got my aftermarket seat today.  When I went to put it on, I couldn’t find one of the hinges.  I’ve looked everywhere, it’s lost.  Hoping someone here has one, or maybe Bent Bike.  An aftermarket set costs over $50 plus shipping. 

Here’s a picture of it.

[Twisted_Twin]

Are they rubber tipped needles and plastic seats or metal needles and metal seats.

If they're metal, you can use a little bit of valve lapping compound and lap the needle to the seat to remove whatever burr is making it hang up and make it seal better.