86 CB700SC jet/filter reccomendations?

[ryushi5]

As the title says, I have an 86 CB700SC. Right now everything with the carbs and air filter are stock. The previous owner did however install a 4-to-1 exhaust.

I would like to know if anyone has any suggestions for jet-kits and air filters that work well. If possible, I'd like to see if there are any functional clip-ons out there since I really dislike the air-boxes on these things.

[Option13]

No to pods. Just no.


Gammer has a well tuned setup with a K&N, 4-1, and rejetted to match, but he hasn't been on in some time. You could try a PM to get some info from him.

[ryushi5]

Thank you, sir.

[Option13]

Sorry I can't tell you more. Gammer is the only person I have heard say he actually tuned his jetting to suit the modifications he made. Just be aware, it's a lot of work for not a lot of gain (changing the air filter and tuning to suit). I think he said he wouldn't do it again if he didn't have to.

[Brittles]

gammer's using a Dyno Jet kit in his bike.

[ryushi5]

Do you think I'd be better keeping the carb and filter stock?  I just wasn't sure if the 4-1 exhaust would negatively affect the bike without changing the air/fuel too.

[Option13]

That depends on the manufacturer. Some claim that their exhausts don't require a retune. You could do a few plug chop tests to see if it's running normal or a bit lean, and go from there.

[ryushi5]

Sounds like a good idea. I'm used to working on old single cylinder bikes, and what we commonly did to test the mixture is to spray a little WD-40 on the intake of the bike. Depending on how the RPMs changed you could tell if it was running lean or rich. Do you know if this still applies with Nighthawks?

[Option13]

You'd be hard pressed to get equal distribution of WD-40 between cylinders with the airbox on, and you can't take it off to test a/f ratio. I would stick with an a/f ratio sensor or a plug chop test.

[ryushi5]

Right you are, everything is easier with one carb ;)

[TDodge7]

Are there any flat spots in the acceleration? Will it go full throttle without a hiccup? Does it Backfire or surge? Pop like hell on deceleration? Is it doing something that would lead you to believe it's out of tune ? How do your spark plugs look ? No point in jetting if it's already running right ya know? Pod filters are nothing but trouble on bikes with CV carbs (clip-ons are handlebars that clamp to the fork tubes) Besides, the 700s has those little velocity stack covers behind the carbs, all the looks of pods without all the problems involved with pods, it'll never run better than it does with that tuned air box.

[ryushi5]

I haven't had a chance to run the bike yet, it still needs some work. Just figured I'd probably be doing some tuning once i have it done. And clip-ons are many things ;) in this case I was referring to clip-on pod filters.

[TDodge7]

Well get it going before you worry about jetting, it might run fine. You could always pull the plugs now and see how it was running the last time it was running, that'll at least give you an idea.

[ryushi5]

Righty-o. I'm just excited about the project, you know? Looking forward into all the things that I want to do.

[TDodge7]

You picked a great bike. My 700s is almost 100% stock right now except I put in a tapered steering bearing kit in, the only other mods I would consider doing is stainless brake/clutch lines and maybe a better fork brace that actually braces instead of flexing on rubber grommets. I've been riding it for two years now and I love everything else about the bike, probably my all time favorite (and I've had more bikes than I can remember) Honda pretty much got everything right on these Nighthawks.

[ryushi5]

Sounds good, I love to hear ideas.

[Brittles]

I'm not even convinced pod filters would even fit on the #1 and #4.........not much clearance with the frame.

[ryushi5]

Yeah, I'd say you're probably right about that one.