K&N RC-2362 install

[Luminoth]

I'm looking at a set of K&N RC-2362 clamp on filteres for my 1980 cb650c and am a bit confused about some of the left over bits when installing them. Specifically, the tube that goes to the container under the bike (for burning leftover hydrocarbons i think?) from the removed airbox and the connection that used to go from the air clear to the removed airbox. Are both of those supposed to be left open when the airbox is taken gone? What is the point of the air cleaner remaining if it's not connected to the engine anymore (or rather, did i waste money buying a replacement stock k&n filter that is no longer used before buying the clamp ons)?

Also, if I throw those clamp ons onto my bike without rejetting, what would the impact be? Just less power when the throttles opened up, or something worse? The dynojet kits are a bit spendy at the moment, so I'm just curious if I can put them off for a month or so without damaging anything.

Thanks in advance for any help.

[Pinhead]

Pod filters without a jet change? The bike probably won't run down the road (if you even get it to start). Especially if you have CV carbs...

[Luminoth]

Hrm, alright. They're not CV carbs from what I've read, but that probably doesn't change the prognosis much.

[Volker_P]

Welcome here!
The main engine vent on the center engine cover should not be plugged. I would expect that a hose with a (vented) container at its end is required. Check if oil collects there and drain from time to time if required. Or just guide a longer hose to the rear for automatic drive chain lubrication.
Pod filters are usually much less restrictive and tune the engine to the lean side. If running reasonably at all, overheating damage may occur. A jet change is recommended, keep an eye on your plugs to have an idea on your mixture conditions.

[old gringo]

+1 on the jetting. I would go up one size from stock main jet (richer) to start with. If you like pods then go with them. I, myself, use a K&N stock replacement filter with 122 mains. However, bike would sputter from lack of air beyond 5000 rpm. I took the cover off of the air cleaner housing and secured the air filter element with fender washers & the stock screws. No more air starvation. Nothing sweeter than a SOHC winding up toward the red line.

[Luminoth]

I was checking the dynojet site again and I guess their kit is only for the CV carbs, which I believe mine (pd50b) aren't. I guess the bike came with default #90 mains in it, and I'm only able to find a set of #95 mains online as a replacement. Is there somewhere specific you can go to find the larger jets I'd need to use those pod filters?

[cb650]

95's are 2 sizes bigger and will work.

[Pinhead]

95's are 2 sizes bigger and will work.

Really? I'm running 102.5's in my '79 and it runs great, maybe a tad lean still. All I've done is remove the airbox lid, open my exhaust by removing the rear baffles, and very slightly opened up the holes in the emulsification tubes. It seems that 95's would be pretty lean when running pods...

Edit: What about the idle circuit? Wouldn't the idle jets need to be larger as well? It seems with my setup, there is a slight stumble when going from the idle circuit to the main circuit; I think it's idling lean and getting closer to stoichiometric the mains.

[cb650]

run what u want

[Pinhead]

I didn't mean to come across as a know-it-all; I've just been wondering if my bike was somehow "different," as I've come across a few discrepancies with regards to performance and gas mileage. Sorry if the inflection of my voice didn't come across in my post.

[Luminoth]

Well, the paper that came with the filters recommends going about 15% bigger, which would be 103 from a 90, so the 102.5 is probably right where it should be. I just don't know where I'd be able to find them. Strangely though, it recommends running a leaner pilot screw for the style I have (backed out about 2 turns from seated) to fix the idle circuit.

[old gringo]

The 122s I mentioned were for my CV carbs which I guess your's aren't. I will defer to those running the slide carbs.

[Pinhead]

Well, the paper that came with the filters recommends going about 15% bigger, which would be 103 from a 90, so the 102.5 is probably right where it should be. I just don't know where I'd be able to find them. Strangely though, it recommends running a leaner pilot screw for the style I have (backed out about 2 turns from seated) to fix the idle circuit.

I bought mine online for relatively cheap. It's been a while, though; I'll see if I can fidn a link.

[Luminoth]

So I've finally got all of this together, using the dual pods and 102.5 main jets, but now I'm thinking either the jets are still too small or something else is wrong. I seem to lose power off and on in the 2k-5k RPM range and have killed it several times getting going out of idle. The idle itself feels fine with the choke open and closed, but the transition out of the idle requires about 5-10 miles of running before I can do it with the choke open.

I've thought that it might be the accelerator pump, but I guess Honda has stopped making replacements for the 1980 so I'm hoping it's not that. The diaphragm on it looks haggard, but there aren't any holes in it. Is there anything else that could cause what I'm seeing? Given that these are the old mechanical carbs and the pilot jet isn't adjustable, I'm somewhat at a loss for how to get things running smoothly.

[Pinhead]

These bikes are notoriously cold-blooded and most people report the same situation with what they would consider a well-tuned bike.

Personally I think it sounds like weak ignition. Check your charging system voltage.