Rogue's NC30 Project

Nasty fuel tube rings.

 

Looking at the diagrams I cannot tell where these would go. Any thoughts?

 

Maybe some super thick pilot screw o rings?

 

Rick is a solid source of information on these machines, and he is super quick to respond. He is arguably the best person to know, when it comes to tuning and setup. Mike Norman is also very helpful, but Rick has done me more solids than anybody I have dealt with. Rick also has a huge advantage....He actually has the parts!

 

They are the choke plunger seals.

 

I will investigate location. I replaced those already (red arrow).
I have not found a seal removed from the carbs that look like these red seals. I went through the images of carb parts, but I couldn't see a good match.

 

Guide to Fitting Choke Plunger Seal (litetek.co)

 

ahhhh. I guess I need to inspect closer. I am in a hurry too much. Thank you for finding that.

 

I've never even seen those mentioned as needing replacing on 700/750 carbs, that's cool that someone makes the seal.

 

Interesting about the choke plungers. But on my 86 700 I seem to have 2 different sets of Main Jet Holders (emulsion tubes) but parts fisch is telling me there is only one part number, I wonder...

 

Needs carbs sorting would be my theory!

Idling has almost nothing to do with any of the jets.

Idle is controlled by the mixture screw (although some crossover with the pilot jet).
Idle to ~15-20% throttle is pilot jet
20-80% is needle
80%-100% is main jet.

The mistake you are making is reading the UK manual...for a JDM bike!

Standard jet sizes are: 1989 Jap model (4 x 110), all other year Jap models (2 x 115f, 2x 118r), all UK bikes (2 x 120f, 2 x 122r).

If you've got an aftermarket exhaust on then I'd go 118f/120r, if you've got a full system then go 120f/122r, if it was an 89 then I'd bump them up as well. If it's stock then I'd leave alone.

No point in changing pilots on a road bike.

 

In the U.S. there is a point. It's called the EPA and bikes made for this market often had the pilots reduced and changing them back to what Honda intended could make a big difference in drive-ability. Not to mention the ridiculous U.S. only "Idle Drop Procedure".

I know these bikes never were officially imported into the U.S. but "Sometimes there is no point changing the pilots on a road bike."

 

It was an NC30 specific comment. To clarify, no point in changing pilots on a NC30 road bike (ie without substantial modifications) that has the standard pilot jets.

 

Sorry. Not trying to jump your shit. A lot of people don't realize the changes that were made to U.S. models and there can be some confusion. It all depends on the application... like you clarified.

Also, "road bike" might not have the same meaning over here. I have some fairly modified "road bikes". We do not have inspections here.

 

Captain, what jet combo do you run in your 86 headered street bikes?

 

PM'd

 

^^^ TOP SECRET!! Don't ask those kinda questions here! lol

As for jet theory. Rick Oliver set me straight earlier. I am back to original jetting since that is what most recommend and the bike is a 1991 from Japan in original form.
The carbs have been through a sonic bath, vapor honed, and followed with another super clean sonic bath. Carb cleaner for all ports. and most small components run through separate isopropyl sonic bath. All o-rings save the sneaky little carb plunger seal have been replaced post cleaning.
I am, however going to Japan soon, so all is on hold until I get back. Already had my son pick up a locally sourced NC30 fuel tank relief valve from Crooober. Maybe I can make it to some moto shops while over there.

 

I just didn't want to dilute your thread with irrelevant info. But I go up 5 sizes on the pilot.

Have fun!!

 

Now that is a sweet patch!!

 

Last time I was over there, Ueno bike town was only a shadow of its former glory. Bummed me out.