UNI pods are definitely better, but...

[griennehornette]

5twins explained that on CV carbs, foam is better than pleated, in the pod department. When 5twins speaks, I listen. Also, there are numerous posts on the forum from dudes installing UNI or other foam pods, and experiencing an amazing improvement.

So I installed UNIs, and took the bike for a spin this cold Canadian morning. Yes, there was a noticeable improvement. Bike idled pretty good and didn't stall out once at a light. Don't think it was just in my head that throttle felt smoother. (And even if it was just in my head, it still makes me happy.) Less spluttering and popping at random moments.

Here's the "but." I still found that after the bike warmed up, idle speed at stops ran high. Better than with the K&N filters, for sure; but I was hoping it would disappear.

When I first start up the bike, idle is low: around 1200; maybe less. (I installed those little chrome speedo and tach units when I fixed up the bike 15 years ago, and somewhat regret that decision. They ain't the most sensitive and/or accurate things in the world.) Anyway, low idle for the first while. That's where I was experiencing stalls at stops.

Then, after either zipping out on the highway or just giving it time to really warm up, idle seems to go up and stay up. With the K&Ns, it was up over 2000 rpm. With the UNIs, it hovers under 2000; but not back down to the recommended 1200-1500.

I don't comprehend this phenomenon. If any of you fine fellers do understand - and care to share your wisdom - I'd be most appreciative.

Gracias, Amigos!

 

[Tomterrific]

If you still have a mechanical advance it most likely is due to the springs losing tension. The lack of tension allows the timing to advance at idle. Try clipping off the loop/hook on the end of the spring and using the top coil to form another loop. The increased tension on the flyweight will keep the timing retarded at idle.

 

[weekendrider]

If you adjust the warm idle down to 12 - 1300 what happens?

 

[griennehornette]

Hmmmm.

Well, I tried adjusting down with the K&Ns; not yet with the UNIs. I have a memory like a sieve, and adjusting down got frustrating, as I quickly lost track of which side I had adjusted how, and pretty much just threw off sync. But near as I can tell, adjusting down did reduced the RPMs; but once the bike cooled off again, it was really hard to start, as initial RPMs were so low. I'd end up tightening the idle speed screw again.

So I'm gonna investigate Tomterrific's idea about the mechanical advance springs. I do still have the original points ignition setup. Seems logical that the springs have loosened up. I'll report back!

 

[TwoManyXS1Bs]

Carbureted engines need to have their idles set on a fully warmed up engine. This means that they need a hi-idle setting during warmup. The stock BS carbs have an enrichner system (the choke) that provides a high idle rpm. Sometimes the choke needs to be turned off before the engine reaches full temperature, and that would require temporarily bumping up the idle setting during that final warmup. The guys have cooked-up a simple idle thumbscrew to help with that.

Have a look in here.

http://www.xs650.com/threads/gggarys-carburetor-mod.47867/

 

[fredintoon]

.
Well, I tried adjusting down with the K&Ns; not yet with the UNIs. I have a memory like a sieve, and adjusting down got frustrating, as I quickly lost track of which side I had adjusted how, and pretty much just threw off sync. But near as I can tell, adjusting down did reduced the RPMs; but once the bike cooled off again, it was really hard to start, as initial RPMs were so low. I'd end up tightening the idle speed screw again.
So I'm gonna investigate Tomterrific's idea about the mechanical advance springs. I do still have the original points ignition setup. Seems logical that the springs have loosened up. I'll report back!

Hi Chris,
us old guys got worse memory sieves than you, eh?
Whyncha build your bike's model & year into a signature line so I wouldn't have to dig into your post record to find out that your bike is a '77D?
Don't that bike have a single throttle cable that works both carbs?
If so there's a spring-loaded balancer thing between the carbs that you set to synchronize the carbs and never mess with afterwards.
And a throttle stop that limits how nearly the carb butterflies will move towards fully closed.
The throttle stop is what adjusts the slow running.
Yes, the throttle cable adjuster will do that too but it ain't the best way.

 

[CoconutPete]

Now I'm curious. When 5Twins, gggGary and Fred in Toon speak I also tend to listen....

So I bought a set of the UNI pods just to see what all the fuss was about.

They have arrived, but the oil for some reason ended up in another shipment and isn't here yet.

Now you done' gotten me curious!

 

[5twins]

You shouldn't use the regular foam filter oil, it's too thick. It's for their standard green foam filters. These black foam pods use a finer foam. Use a 50-50 mix of gas and motor oil.

I don't think the pods, UNI or K&N, are responsible for the idle problems. I've run both and never had idle issues. The K&Ns mostly cause their problems higher up in the rev range, from the upper midrange into the main circuit. I think this just may be a case of tuning or fine tuning (or lack there of). Before you can do this successfully though, you have to know and understand what the various screws you're turning are doing, lol.

 

[TimeMachine]

Uni Pod converted from pleated myself ! Had success with appropriate jetting and stumbling symptoms were resolved easily ! Agree that whether its pleated or foam the pods are not affecting the idle . -RT

 

[MaxPete]

The other thing to check with respect to a high idle is the routing of the throttle cable. I had my tank on and off so many times that somehow, I muffed the routing and got a situation where if I turned the handlebars lock to lock, the idle would race. Not very nice in traffic (nearly rear-ended a city bus).

Check that cable GH - it may just be hung-up somewhere.

 

[CoconutPete]

You shouldn't use the regular foam filter oil, it's too thick. It's for their standard green foam filters. These black foam pods use a finer foam. Use a 50-50 mix of gas and motor oil.

I ordered a can of their own since it was right next to the 2-pack of filters and I was in a shop happy mood. Should be delivered Wednesday, so I know what I'm doing then!

 

[griennehornette]

Many thanks for all the replies, gents. Yep, there was a reason my nickname on that long-ago XS650 list-server was "chimpy." I was a totally non-mechanical guy who decided to refurbish an old bike in order to learn. While the bike was stored for 11 years, I seem to have forgotten much (most?) of what I learned. I know the left hand (when sitting on the bike) screw - the one that gggGary set up for easier turning by hand - controls idle speed. Somehow I surmised that the link screw (buried deep within to make it really hard to adjust... possibly because it's not supposed to be adjusted) had to be adjusted every time the idle speed screw was adjusted.

I'm not saying it makes sense. Just that I got it stuck in my head that way, somehow.

Anyway, I did clip the mechanical advance springs, and made new hooks to set them in a bit tighter. After a blatt on the highway tonight, idle returned *almost* to what it was on start-up. Oh, and I did tighten the idle screw up a bit. Yeah, I know that's not very scientific, messing with 2 variables at once. But let's be honest; I barely know what I'm doing. Careful adherence to scientific method ain't gonna compensate, when I'm still fuzzy on some real basics.

Nevertheless, I press on! Perhaps I wasted my hard-earned dollars on the UNIs, expecting them to accomplish something they just aren't intended to accomplish. But I had fun doing it! And the Hornette looks real snazzy, as I kept the outer, red foam sleeves on.

BTW, I could only find one brand of filter oil in town. Lucas high-performance foam filter oil. It's blue, which is kinda nice. Makes it easy to see where it's been applied, and where it hasn't. It *is* fairly tacky, and I *did* get enthusiastic about making sure every square millimeter of the pod foam got saturated. So if it's anything like the too-thick UNI product... well I may have caused myself a whole new problem. I guess we'll see.

Whatever! That's how I roll. Learn by mistakes! In theory... I make so many of them; I'm honestly not sure which mistakes to connect to which lessons. Which makes the learning bit fairly challenging at times. That's pro'lly why I have no problem making the same mistakes over and over again.

But let's not get hung-up on a few mistakes! I'm riding again for the first time in way-too-long! It's making me grin. Yeah, maybe I'll destroy the bike in my cheerful ignorance. But dammit; I'll have fun doing it ;-)

Thanks again muchachos. I go to adjust something which may or may not require adjusting.

 

[weekendrider]

For you I wish many miles and tons of fun.

 

[MaxPete]

Atta boy GH - that's how I learn too!

Hey - where did you get those Unipods? Were they local in Sarnia?

Pete

 

[nj1639]

Note....the idle speed adjustment screw on the left controls both carbs throttle plates.
The adjustment screw in the middle, between the carbs, adjusts the right carbs throttle plate only.
Bench synching is getting both sets of carbs throttle plates opening the same amount. Once the carbs are bench synched and remounted, you shouldn't have to revisit the adjustment between the carbs. Key word is shouldn't.....not 'never', but I'll note that once bench synched I've yet to have to make any adjustments in the middle, just on the left side idle adjustment screw.
Figuring your method of bench synching is up to you, there are threads about using light, paper, straight pins and I even recall where somebody mentioned using popsicle sticks.......I use the straight pins.

 

[griennehornette]

Atta boy GH - that's how I learn too!

Hey - where did you get those Unipods? Were they local in Sarnia?

Pete

Yep. I went to the local powersports store. They sell jet-skis and ATVs, and have a decent parts department. The parts guy looked them up, scratched his head, and said, "Wait a minute." He emerged from the back with a surprised look and the right pods. Just happened to have 2 in stock. No more expensive than ordering online. The parts guy and I agreed that it ain't often; but once in awhile, things work out like that.

 

[griennehornette]

Note....the idle speed adjustment screw on the left controls both carbs throttle plates.
The adjustment screw in the middle, between the carbs, adjusts the right carbs throttle plate only.
Bench synching is getting both sets of carbs throttle plates opening the same amount. Once the carbs are bench synched and remounted, you shouldn't have to revisit the adjustment between the carbs. Key word is shouldn't.....not 'never', but I'll note that once bench synched I've yet to have to make any adjustments in the middle, just on the left side idle adjustment screw.
Figuring your method of bench synching is up to you, there are threads about using light, paper, straight pins and I even recall where somebody mentioned using popsicle sticks.......I use the straight pins.

Heh. I'm a smart enough guy; but sometimes I can be - as my father-in-law says - about as smart as a sack of hammers. When you describe it Paleo, it makes perfect sense. I dunno how I got it into my head that I had to adjust both the screws separately. Ah well. Live and learn.

Thanks for clearing the fog in my understanding!

 

[5twins]

A good bench sync will get you very close, maybe even right on, but after the carbs are installed and the bike is running, you can check the sync with a manometer if you want. Like I said, it should be very close but may require a small adjustment to get it perfect. Then you should be good for several thousand miles at least before it needs to be checked again. The linkage set-up on these holds it's adjustment very well.

Idle speed adjustments with the screw on the left carb moves both butterfly plates together through the linkage so sync is not changed. I find my bike usually needs a couple setting tweaks during the season. Once the weather gets consistently hot, I usually need to turn it down a little bit. For the cooler spring and fall I have to turn it back up a bit. We're not talking much adjustment here, maybe 1/8 turn of the screw.

 

[griennehornette]

Roger that 5twins. That was a big mistake I was making; thinking the 2 screws needed to both be adjusted (not cluing in that once synched, I only need to bother with the left speed screw). The idea hs finally made it's way through my thick skull. When I get some time this weekend, I'll get it sufficiently warmed up, use the manometer to re-adjust sync, and then leave the linkage screw alone for a good long time!

 

[griennehornette]

Question about UNI pods and the sticky oil making them bung up. It may be just in my head; but I kinda feel like the Hornette is a wee bit sluggish from a stop. I did get pretty enthusiastic with the oil, so I'm wondering if the pods are choking the engine. I guess I could slap the K&N's back on for comparison sake...