Topic: How does the engine perform between rich vs lean?

[juntjoo]

I have two situations where it struggles a bit,

1, before engine warms up, and

2, in particularly warmer, 70+ farenheit tempuratures, as I've noticed when it's colder I barely notice any performance issues...

which come down to hesitations with higher rpms or rapid throttle action. If I turn the throttle slow enough no issues but one day I might need to outrun the cops.

In general I'm trying to understand what of the fuel/air mix can be determined by the engine's performance if anything at all.

I'm planning to take a closer look at the plugs immediately after(shutting off engine) symptoms occur, but I also want to understand better what different behaviors indicate If anything in particular.

Thanks!

[Scott S]

 What did you end up doing about filtration? Are you still running open carbs?

[Don R]

 

[juntjoo]

What did you end up doing about filtration? Are you still running open carbs?

I've got pod filters, 1 over 2 carbs k&n type behind about a foot of hose which sort of simulates the stock air box and I've read where the t-vents aren't connected back into the air box someone had similar problems, two conditions I'm sure have some sort of an effect on performance but I'm just trying to first better understand the general question of my post. When I had no filters it ran like, what do you guys say? A raped monkey?

[juntjoo]

Here's a pic

[Scott S]

 That's....interesting. What are the red key looking things?

 Your plugs will tell you a lot. Bogging at upper RPM's usually indicates a rich condition.

 Swear to heavens man, if your carbs are clean now, and with the stock exhaust, just get the correct boots and put the air box back on it. It'll be the last time you'll ever have to remove it as long as you keep the gas tank clean and use non ethanol fuel (or a fuel stabilizer).

https://www.ebay.com/itm/81-82-HONDA-CB650-CARB-AIR-CLEANER-BOX-DUCT-BOOTS-SET-4BOOTS-21-CB650BINAB/142959435125?_trkparms=aid%3D222007%26algo%3DSIM.MBE%26ao%3D2%26asc%3D20131003132420%26meid%3D0f99ebc3d8d64ebb8665c7d45742f972%26pid%3D100005%26rk%3D2%26rkt%3D9%26sd%3D143003064347%26itm%3D142959435125&_trksid=p2047675.c100005.m1851

[juntjoo]

That's....interesting. What are the red key looking things?

 Your plugs will tell you a lot. Bogging at upper RPM's usually indicates a rich condition.

 Swear to heavens man, if your carbs are clean now, and with the stock exhaust, just get the correct boots and put the air box back on it. It'll be the last time you'll ever have to remove it as long as you keep the gas tank clean and use non ethanol fuel (or a fuel stabilizer).

https://www.ebay.com/itm/81-82-HONDA-CB650-CARB-AIR-CLEANER-BOX-DUCT-BOOTS-SET-4BOOTS-21-CB650BINAB/142959435125?_trkparms=aid%3D222007%26algo%3DSIM.MBE%26ao%3D2%26asc%3D20131003132420%26meid%3D0f99ebc3d8d64ebb8665c7d45742f972%26pid%3D100005%26rk%3D2%26rkt%3D9%26sd%3D143003064347%26itm%3D142959435125&_trksid=p2047675.c100005.m1851

Thanks... My plugs look good I think. And I have been tempted, like the other day riding in the rain, to go back to stock, and at some point I'm sure I will like def if and when I sell it, but for now I'm just enjoying playing with it and learning how it works.

So my plugs look leaner than stock, richer than when I was running bare, no filters. Rich huh? Hmm.. Interesting, and that's why I thought I'd try to learn more before I bored out my extra set of jets. Maybe I should give these k&n's a cleaning? I wonder if I route my t-vents into one of the filters housings..

I wish I knew how it ran when it was stock, but all I remember was how it ran the way I rode which was very slowly lol. I've since morphed into my bike a bit, and the road. It's getting fun and even though I ride faster and maneuver about more I feel a lot safer. Of course I'm all about safety and riding like they're trying to kill me and keep extra aware of my surroundings, but I feel a lot safer. Um, so yeah, I bet when it was stock it was perfect. No biggie tho. It's actually like a governor keeping me safer, but of course, I want to option to outrun the cops. Anyway, just fishing for knowledge on the rich/lean subject. Doesn't sound like it's so straight forward and simple.

Oh, and thanks anyway, but I don't need those boots last I checked. It's just tight in that area no matter how you squeeze the carbs in.

[juntjoo]

The red things are little handles on the hose clamps. They're a buck extra at O'Reillys. Make it easy to get filters off if need be, and provide a post to anchor the ties I use to hold the filters in.

[juntjoo]

What I notice most besides high rpms struggles, if it's not the same problem is this cooler(SWFL temps) starting stumbling /stalling upon rapid throttle action. Check out my plugs though. I thought they'd be darker but apparently I'm running lean. I checked these right after a cold start condition a couple times(10+/- seconds) to try to ensure the plugs would show the immediate signs.

Tell me, a carbureted engine that's struggles/stalls upon rapid throttle action can be due to either a rich or lean condition or would it be more likely one or the other? Again, besides the various mods from stock here that complicate the situation I just wanna understand the mechanics /physics here better whatever anyone can offer. Thanks!

[PeWe]

Make sure that ignition is properly set.
If not, it will trick the carb jetting and even make you to think that carbs need to be re-synched when engine runs uneven rattling a lot at idle and start.

[juntjoo]

Make sure that ignition is properly set.
If not, it will trick the carb jetting and even make you to think that carbs need to be re-synched when engine runs uneven rattling a lot at idle and start.

Hmm, thanks. So you're referring to timing right? I'd guess that would be since last time I did that as it seems to idle fine, not perfect, and besides symptoms from cooler temps it runs good. ENGINE temps I should specify since cool climate temps improve overall performance,.