collapse

www.dimecitycycles.com


www.restocycle.com

www.CITYLIMITMOTO.com

www.jadusmotorcycleparts.com

www.bisonmotorsports.com

www.speedmotoco.com

www.cognitomoto.com

www.townmoto.com

www.sparckmoto.com

www.Moto-Madness.com

www.pistonsociety.com

www.steeltowngarage.com

QUESTIONS ABOUT THE SITE? TROUBLE REGISTERING? ADMIN@DOTHETON.COM

Author Topic: AUXILIADORA 1981 HONDA CB750K BUILD  (Read 2631 times)

Offline PRIMEWORKS

  • Posts: 18
Re: AUXILIADORA 1981 HONDA CB750K BUILD
« Reply #30 on: Sep 01, 2017, 23:50:48 »
Dumb question but are they leaking from the overflow or could it be very bad gaskets, cracked bowls or if they have drains, from leaking drains?

They were leaking from the bottom of the bowls where that nipple is for a hose.

So, do you have a stock airbox? If so then your simplest plan will be to keep it.  If not, getting it to run well with pods may not be too dreadful (some bikes are evidently).  Replacing the carbs altogether will be dreadfully expensive unless you get used, and whether stock replacements or from an alternative bike, you either are where you are now (you already have stock used carbs) or will likely see plenty of jetting work to get it to run properly - of course you could get very lucky - but it's not usually how it goes.  The vacuum valve itself is not a bad thing.  If it works, it's fine.  If it has issues (this is not your carb leaking problem) then fix it.  Just because others say it has problems does not mean it is terminal.  Of course you can simply eliminate it as long as the petcock works properly manually so you can turn off the fuel when you are parked.  If you bought aftermarket rebuild kits it is very possible that this is an issue.  If you kept your old parts put them back in.  The assembled height of the needle/seat assembly is CRITICAL, and aftermarket assemblies often are not correct.  You can "fix" that problem by adjusting the tang that sets the float height, but you trade one problem with another, which is screwing up the kinematics of the float mechanism by having the tang not meet the needle's tensioning pin at 90o when the fuel level is correct.  While you're thinking about this, make sure you have the correct washers under the seats as this will hugely affect the resulting assembled height of the parts.  Another reason to have the OEM factory gasket, seat and needle.  For the record, these parts almost NEVER need to be replaced unless mechanically damaged by corrosion or stupidity.  I've seen some wear on 2-stroke race motors, but otherwise consider them to be lifetime reliable only needing cleaning and polishing to be good as new.  As previously mentioned, it would be good to know EXACTLY where the leaks are.  I reckon everyone is presuming it is from the bowl overflows.  Assuming that to be the case, you should take off the bowls and fill them up with gas on the bench almost to the top of the overflow tube.  If no leaks, you can go back to troubleshooting the floats, mechanism and need/seat assembly.

I do have the stock air box and I'll likely be using it. Maybe I'll try out the pods and fiddle around with carbs to see if it can run half decently but we'll see. Luckily regarding the carbs, I still have all the original parts I replaced so before reinstalling the carbs I'll put the OEM parts back in and see if I have any issues. (Sigh never did I realize how big of a pain these were but I guess that comes with the glory of owning this beauty).


Dude I'm totally enjoying reading through your build - anyone working on '81 CB750K is cool as f*** as far as I'm concerned.  Might be a bit biased, but hey.

If you're still having issues with your carbs, there's a dude called Mike Nixon (he has his own website, you can google the guy) - he knows a ton about Honda carbs.  I got a ton of help here on the forum with mine, and spoke to Mike a load as well. Got mine running like champions, yours will too mate. 

Keep on keepin' on, high fives from Montreal

Thanks man! I really appreciate it ! Appreciate the tip. Hopefully I can get her done before winter comes but I live in Winnipeg so you never really know when the snow is going to hit around this time.

Current list of things to do:
1. Order a braided brake line. Old one was filled with a bunch of gunk and I don't want to fill my new master cylinder with any of it. Also the old brake line was to long so I need a shorter one.
2. Wire (You better Believe Im going to have a million questions). I got a Motogadget M unit and the only thing I feel like I'm really confused about is wiring in the components that orignially came with the bike aka spark generator, reg/rec, etc).
3. Install carbs with some new gas and see if she starts!!
4. All the other shit thats just for looks aka a seat and a colour for the rear cowl and tank

Offline PRIMEWORKS

  • Posts: 18
Re: AUXILIADORA 1981 HONDA CB750K BUILD
« Reply #31 on: Sep 07, 2017, 00:02:05 »
Small update!

ordered a new front braided brake line



Also got a new ignition to replace the old massive one and relocated it to the side of the tank where a side cover would normally attach for a super clean look (in my opinion atleast)







Offline PRIMEWORKS

  • Posts: 18
Re: AUXILIADORA 1981 HONDA CB750K BUILD
« Reply #32 on: Sep 11, 2017, 09:44:46 »
So close yet so far.

Got the controls wired. Now just to install them and run them to th m unit. Also stripped my clutch leveer and polished it to match the front end of the bike (pics of it later).

Here's a bit of a teaser

Sent from my SM-G935W8 using Tapatalk


Offline CB MIKE

  • Posts: 91
Re: AUXILIADORA 1981 HONDA CB750K BUILD
« Reply #33 on: Sep 11, 2017, 18:48:32 »
Man that rear end is low... no bumps lol. She looks great though keep it up!

Sent from my SM-G930V using DO THE TON mobile app

81 CB750C

Offline PRIMEWORKS

  • Posts: 18
Re: AUXILIADORA 1981 HONDA CB750K BUILD
« Reply #34 on: Sep 11, 2017, 19:43:35 »
Man that rear end is low... no bumps lol. She looks great though keep it up!

Sent from my SM-G930V using DO THE TON mobile app

I'll forsure be avoiding as many bumps as I can hahahaha