Topic: Mini project PD46C rebuild

[AlekStooge]

Ok, that clears it up. I can see now why they would call a IMS an air screw. By any chance do you know which brass intake tube leads to the IMS and which one to the pilot?

[Darren Jakal]

I’m not sure but I think the left one feeds air to both the pilot and IMS and the right one (centre) feeds the main jet. You can see on the carb body where the tubes lead by following the casting.

Doesn’t really matter, but what you want to see is that spraying carb cleaner down these brass tubes that it is coming out the other end. With the jets, emulsion tube and IMS removed the spray should come out of these holes easily if they are clean.

[AlekStooge]

Thanks DJ!

I contacted someone local about plating. He is a small shop that does restorations for antiques. I sent an email with a photo.

I want to make sure which parts are what material and what they are plated with.The steel and aluminum are obvious. What are the shafts of? Brass? What about the choke plates? Brass again? Please help thank you.

[AlekStooge]

For the carb fuel links. Does anyone know if this kit which I have included the o-rings for those link tees?
https://4into1.com/deluxe-carburetor-rebuild-complete-kit-honda-cb550k-1977-1978/

I sent about 28 parts to get plated today. Including the throttle and choke shafts, I think they'll be fine after plating.

[FourUsTry]

I think the 2 biggest o-rings in each set are for the fuel connectors (not technically T-s on these carbs). You end up with 2 extras. There is also another o-ring not needed for these carbs (maybe because the main jet has no o-ring). The OEM kit is the same.

Generally the brass on aftermarket kits is not good and you are better off cleaning up the original brass or getting Keihin replacements where available. If that is the case I'd just look for an o-ring + gasket kit or just make one up from the o-ring specs and get the gaskets. Oddly, the OEM kits have the wrong top gasket (one alignment pin hole is offset) so get the 4into1 top gaskets or another one that is correct.

[AlekStooge]

Yes, they are. 4into1 confirmed it. Sweet they offer two extras since our carbs use only 6. I'll be reusing my needle ciriclip. In what orientation does the IMS, washer and o-ring go in?

I already have the 4into1 kits I posted above. I was thinking the same thing. I don't see emulsion tubes available so, I'll polish up the old ones.

I dropped off carb 2 at a machine shop. The 5x10 flathead screw holding the push/pull, I had to drill it and the head broke off. My screw extractors are far away. He was saying he'll heilicoil it. Next door is a speciality fastener shop (how convenient) and I picked up a bag of fasteners I needed. Allen heads for the slide to throttle shaft retainer as well as the intake plate. I got a slightly larger head on the 3mm for the slide screw I mentioned earlier. It was bent. I did it the other way around actually, the machinest has the new flathead screw in hand.

[FourUsTry]

The IMS order is needle, spring, washer, o-ring. Here's a pic from the PD42C thread that shows it nicely:



If you already have the 4into1 kits that is fine: just keep the brass as emergency backups. If you need to rejet you may be able to get Keihin jets/needles from JetsRUs.com.

[AlekStooge]

Yeah I already got Keihin jets and needle valves from JetsRUs. Needle jets are not available there.

[AlekStooge]

I got back to my carb rebuild after my friend received his Amal carbs that were made for his R17. I'm like I got to get back to this after hearing that bike run.

Everythings back from plating. I installed the felt washers on the chock shaft. I can't get the two felts on the throttle shaft. Unfortunately after messing around enough with one of them tore. They won't go pass the lip into the grove. I've tried socket and hammer, even using the shaft itself.

Another thing is I'm looking at the replacement O-rings for the throttle shaft and they look too slim. See photos. I'm thinking could I just keep the old ones in. They look alright. Now I'm thinking.... would I be able to use a rubber O-ring instead of the felts for the outside carbs?