Topic: The stuff BETWEEN the carbs.....

[JakeLee]

I have done the searching part for my 78  750K on carb parts and not come up with the answer I needed.  I can get kits of course for the individual carbs, but what about the stuff between the carbs?  Not that they leak now, but I sure the fuel tube o-rings are gonna leak if I do not replace them.  I did not see them in the kits on the sites I looked at.  I am also looking if anyone has the size specs as well as good sourcing on the air/vacuum tubes between the carbs as well.

[mick750F]

  You might want to check the Honda carb kits if you haven't already. I'm pretty sure that they include those o-rings.

Mike

[Clyde]

There are 8 o-rings altogether (K0 has 4). The last time I tried to buy some, I had to go to David Silver Spares in the UK. Honda in Oz did have any in stock and said they were unavailable.
The part number is 16173-044-004. The size is 7.7 by 1.9
Good Luck
Clyde

[eldar]

As long as it is fuel resistant and fits, an o-ring is an o-ring. Same with tubing. As long as it fits and is fuel resistant.

[Clyde]

Typo Correction!!!!
The size is 7.8 by 1.9
BTW The 7.8 refers to the ID and the 1.9 is the width of the o-ring section
This is a standard Japanese (JISB 2401)  o-ring Type/size P-8
Try this website http://www.usseal.com/Oringdim.htm
or this one http://www.rocketseals.com/files/WebORings_Metric.pdf
Close matches are AS 568A No 011 which is a standard imperial o-ring 5/16 by 1/16 (maybe a little too small in cross section width) or No 109 whch may be too thick at 2.5mm, but I would try to get the correct size.
Good Luck
Clyde

[Bodi]

At least try Honda. There should be a seal kit that includes the top gasket, float tank O-ring, and O-rings for all the fuel feed tubes, drain screws, jets, and the float valves. These are surprisingly still available for many older bikes. About $20.00 a carb I think.

[markpeddle]

Hi guys, because we're on the topic......I've just picked up some kits for my '78 550. Of course I can't find any diagram or description to help me tear these apart and put 'em back together. Maybe my lack of knowledge in general should concern me but I'm of the mind that I'd prefer to give it a go and then pay someone AFTER i mess it up. Can anyone direct me to an exploded diagram or something that can help me with this project? Thanks in advance.

[pwright]

Mark,

I got the exploded diagram from somebody here on the sight. However, it's on my computer at home and I won't be able to get to it until tomorrow... if nobody's posted it by then I'll throw it up here.

I also had some questions on these carbs as none of the Clymer manuals covers the later models. I just rebuilt them a week ago (had them apart twice) and can answer questions if you have any... what kind of shape are yours in? I decided not to pull the slow jets (pressed in) the first time I took them apart, and it ran like crap. Took 'em back apart, pulled the slows to clean, and now it runs excellent.

Later,
-Pat-

[JakeLee]

I decided to pull the carbs apart completely.  If you plan to do this, run out and get your M3 x .5 tap to chase the threads after you remove the screws from the choke plates. Don't forget 8 new screws.  (Carburetor engineer:"OH YEAH, lets damage the ends of the screws so that they will never back out and also f#$k up the threads when you need to remove them ") Never heard of thread locker evidentally.

Are you certain about that measurement on those orings?  My crummy calipers showed about 5.5mm O.D. on the groove on the fuel tube and about 9.5mm on the I.D. of the fuel inlet on the carb passage.  I believe the 1.9mm thickness, but not the ID of 7.8mm as stated on earlier posts.

I did not disassemble the link arm assembly to the throttle slide.  The jet needle was clean on all four carbs.  Any reason to tear this assembly down??

[Clyde]

JakeLee,
Apologies, my mistake, I was thinking that you were referring to the earlier 750 carbs. I should learn to read the question properly (I have been saying that since my school days).
The earlier carbs are 7.8mm ID and the carb inlet is about 11.3mm. This gives a crushed o-ring ratio of 90%
I have checked my parts books and can find no reference to any part numbers or sizes for the K7/8 or F2 carbs.
My only suggestion is to look for 5.5mm ID o-rings with about 2mm thickness,or try to find an American AS568 equivalent (possibly a 107 which has an ID- 5.2mm and CS 2.62mm)
Sorry for the confusion
Regds Clyde

[hcritz]

Hey Guys...
I just got a set of gaskets(o-rings) for my 77 750 from Honda...the Atlanta warehouse had them in stock and I got them in a few days. I need to replace the float bowl o-rings as mine tend to ooze a bit when on the side stand. It appears to include the o-rings
for the fuel tubes etc. also new gaskets for the slide adjustment caps. really didn't need all of that...but the only way they were sold. A bit expensive at 16 bucks per carb though...
Oh Well...should stop the mess on the starter cover.

[JakeLee]

After much searching, I managed to find a good source for the JAS (Japanese Automotive Standard) orings that I needed.  Unfortunately I had to buy 100 of them, all I need is 6.  I am going to assemble them this weekend, put my gas tank in the rafters to simulate 3 times the normal pressure on them and make sure they do not leak.  If all goes well, I will graciously off them to the members of this site who have a K7/K8/F2 who may need them.

BTW:  Honda actually still sells the part or I should say assembly of the o-rings on the tubes, $35 each.  I am a cheap and I want to get away with the $12 I have spent.

[canttuckmyshirt]

Sorry to bring back old topics...

Any one have the size for the Fuel-T Orings for a 72 CB500/4? Mine are too trashed to meassure.

Thanks!

[flatblack]

Honda should still have the kits that include the o-rings, bowl gasket (another o-ring) and slide cover gasket. Don't have the part number handy.

I just bought a bunch of o-rings from McMaster-Carr <www.mcmaster.com>.

Try this page: <http://www.mcmaster.com/nav/enter.asp?partnum=9262K121&pagenum=3277>.

This guy sometimes has the o-rings for the 400/F: <http://motors.search.ebay.com/_W0QQsassZhonfours>. He might have something for your bike.

HTH...

fb

[Kevin400F]

I have some O-rings on hand for the CB500/550 fuel tubes.   E-mail me.

Thanks,
Kevin

[bryanj]

500/550 are the same size as the 750, or at least the same part number according to my VERY old parts book. So that makes em 7.8 x 1.9