Topic: 1972 CB350F First RestoMod

[sbeckman7]

I did a quick search for 3 piece oil rings as well before buying the eBay set.  They just don't seem to be out there for these little engines.

[zammykoo]

Progress has been slow due to life  (yeah I know) but I've been looking at different abrasives and polishes to test on some covers. I just attached a spiral buffing wheel to my drill press with white compound and looks like it's working quite well! I used a brass wire wheel first, but looks like it might be too abrasive. I'll have to go back and use something with finer grit and repolish.



What it looked like before:


Then started carb disassembly. It got late so I didn't get to finish, but I noticed something very worrisome. One of the main jet posts are chipped at the end.
It doesn't appear to go as deep as the gasket, but still want to ask for your thoughts. Do I need a replacement body?   

[zammykoo]

Oh god, what did I get myself into... getting ready to do a deep cleaning. I need to get a rebuild kit too. If the jets are good, is this what I need? Honda part #16010-333-315. Looks like I can get 4 sets for $60 shipped.

Looks like the kit includes:

Float bowl O-Ring gasket
Float needle valve seat o-ring
Float bowl drain screw o-ring
Air mixture screw o-ring
o-rings for the line that connects the carburetors
Top Cover Gasket

And for the vent tubes (that links from one carb to the next) would I find that at a local hardware or auto parts store?

[zammykoo]

I may have lucked out because it seems like the previous owner began doing a rebuild but never finished. They installed fresh top and bottom gaskets (or appears to be new). They popped off with ease upon unscrewing the bowls/covers. I can probably go ahead and use these, which leaves me with needing new o-rings.



Trying to look at all of my options here. I can place the order the kits posted above and wait a week to receive them... or run to the local HF and try one of their assorted o-ring packs. http://www.harborfreight.com/225-piece-metric-nitrile-o-ring-assortment-67609.html

Based on forum member danfr's post, the pack contains all the needed sizes (close enough in measurement). Maybe they will work? It's only $5 for the pack - I'll give it a try and report back.

thanks for the reply Bryan.

I did some more digging around and I think I found the sizes although I'm not too sure how credible the sources are. I figure I'd post my findings in case someone with a 350F or 400F is looking....

Main jet O-ring:
1.2mm cross section x 3mm I.D. Quantity 4

Float Valve Seat Seal
1.5mm cross section x 5mm I.D Quantity 4

Fuel Connect
1.9mm cross section x 5.8mm I.D Quantity 12

I think I remember Hondaman stating that most metric O-rings range by 0.5mm so I may need to do some rounding. Also I think he mentioned Buna fits a bit bigger than Viton or Visa Versa...??

I still need one top gasket. Maybe I'll search the salvage yard this weekend.

[sbeckman7]

Let me know if you decide you do want to get OEM rebuild kits.  I have 4 of them unused as I was going to rebuild my carbs and then found my insides to be beyond repair.  Yours for $50 shipped! 1 set was opened, the other 3 are still sealed.

[zammykoo]

Let me know if you decide you do want to get OEM rebuild kits.  I have 4 of them unused as I was going to rebuild my carbs and then found my insides to be beyond repair.  Yours for $50 shipped! 1 set was opened, the other 3 are still sealed.

I appreciate that, Spence! If I can't get the o-ring set to work, as previously mentioned, then I may go for that. What rebuild kit did you get?

[zammykoo]

Playing with some polish. Took about 5 mins on the polishing wheel for these nice results

[sbeckman7]

Looking good   The rebuild kits I purchased are Genuine Honda

[zammykoo]

Looking good   The rebuild kits I purchased are Genuine Honda

Good to know! I'll definitely let you know if my o-ring idea doesn't work out. I'll have a better idea this weekend when I can swing by HF.

[zammykoo]

Well these carbs are full of surprises! I had an "oh snap" moment (literally) with one of the fuel connectors tonight. If anyone knows where to get one of these I'd appreciate it. If not maybe I can rig one up somehow...



And got more goodies today!

[sbeckman7]

I have the connectors along with my full set of spare carbs

[zammykoo]

I have the connectors along with my full set of spare carbs

Cool thanks, I'll keep that in mind. I'll see if I need anything else after checking out the local dude's spare parts.


A side question for all. Feels kind of like a dumb question but I'll ask anyway (I couldn't find a definitive answer). Do I need to split the cases and rebuild the bottom end while I'm working on the top end? This bike has not been running for at least 25 years. The kick starter spins the crank smooth as butter after I removed the stuck piston. There has been oil sitting in it I believe this whole time, and I feel no resistance while shifting through the gears. Maybe the seals need to be replaced anyway?

[Bankerdanny]

The definitive answer is maybe. LOL

On the one hand the SOHC's are pretty robust and so chances are good that the bottom end is in fine condition. On the other hand you already have the engine partially disassembled, so there is an argument for splitting the cases and inspecting the mains and gearset. If they look good you can button it back up.

The obvious downside of choosing to believe that the bottom end is in good shape is that if you are wrong you have to pull it apart all over again.

[zammykoo]

The definitive answer is maybe. LOL

On the one hand the SOHC's are pretty robust and so chances are good that the bottom end is in fine condition. On the other hand you already have the engine partially disassembled, so there is an argument for splitting the cases and inspecting the mains and gearset. If they look good you can button it back up.

The obvious downside of choosing to believe that the bottom end is in good shape is that if you are wrong you have to pull it apart all over again.

Ah,  word of the wise.  I was in the fence but this is the push I needed.  Hopefully I can get to it this weekend!