1980 750 LTD colortune results...and questions

Picture in case I confused the heck outta you. I'm an engineer, so writing or common sense don't come natural to me :laugh:

These transition holes (called bypass on my manual) are labeled 5 in the diagram.

Alright, got an update.
I checked all fuel levels - good
took off carbs (going on 20 here) and checked pilot system on 2 - good.
Bench synch, put back on, quick and dirty vacuum synch.
put carbtune in #2. no firing at idle. wtf...
put carbtune in #1, same as yesterday, 5 turns out.

SO, I tracked down #2's issue. Leaky carb manifold. Pulled it off, it looked great, but the gasket maker someone used looked rough. Got some gas resistant stuff, slapped it on, now have combustion at idle

SO, I set all screws 2 turns out, start and do quick vaccuum synch. All seems good, on to carbtune...but when I put it in #1, the bike runs like crap. I put regular spark plug back in, purs like kitten. For some reason it doesn't run as well with the carbtune plug... It's getting good consistant spark because I can see it through the glass, so I can't imagine what the deal would be...any ideas?

So, carbtune hasn't helped me tune my carbs...yet...but it found that #2 wasn't firing at all. So, I'd say at this point, it's a handy tool.

5 turns out just sounds wayyyyyyyyyyyyyyyyy out

if I tune my pilots according to Colortune's universal instructions I might just have too much fuel causing the high idle?

I did find that having the mix screws at 2 turns or 3 turns out makes a surprising difference in the idle speed when warmed up. So........... you could be onto something.

A few weeks back I took off the pods and put an airbox on mine. Jetted down almost, but not quite, to stock and have been playing around with the mixture screws since. I would turn each a half or a quarter turn and run the bike for a few days. To make a long story short the bike seemed to take forever to warm up with mix screws at 2 turns out which is stock setting. And running just did'nt feel right at 3 turns out. It felt sort of rough. I ended up this afternoon at 2.5 turns out which feels good and I think I'll leave them there. After using tha Carbtune for a synch I was happy.

I might try a Colortune sometime. Sound like a good tool and a buddy use to swear by it for his car

JR wrote:

5 turns out just sounds wayyyyyyyyyyyyyyyyy out

if I tune my pilots according to Colortune's universal instructions I might just have too much fuel causing the high idle?

I did find that having the mix screws at 2 turns or 3 turns out makes a surprising difference in the idle speed when warmed up. So........... you could be onto something.

A few weeks back I took off the pods and put an airbox on mine. Jetted down almost, but not quite, to stock and have been playing around with the mixture screws since. I would turn each a half or a quarter turn and run the bike for a few days. To make a long story short the bike seemed to take forever to warm up with mix screws at 2 turns out which is stock setting. And running just did'nt feel right at 3 turns out. It felt sort of rough. I ended up this afternoon at 2.5 turns out which feels good and I think I'll leave them there. After using tha Carbtune for a synch I was happy.

I might try a Colortune sometime. Sound like a good tool and a buddy use to swear by it for his car

I got one unopened, still in the box i'll sell ya, let me know

stonemaster wrote:

JR wrote:

5 turns out just sounds wayyyyyyyyyyyyyyyyy out

if I tune my pilots according to Colortune's universal instructions I might just have too much fuel causing the high idle?

I did find that having the mix screws at 2 turns or 3 turns out makes a surprising difference in the idle speed when warmed up. So........... you could be onto something.

A few weeks back I took off the pods and put an airbox on mine. Jetted down almost, but not quite, to stock and have been playing around with the mixture screws since. I would turn each a half or a quarter turn and run the bike for a few days. To make a long story short the bike seemed to take forever to warm up with mix screws at 2 turns out which is stock setting. And running just did'nt feel right at 3 turns out. It felt sort of rough. I ended up this afternoon at 2.5 turns out which feels good and I think I'll leave them there. After using tha Carbtune for a synch I was happy.

I might try a Colortune sometime. Sound like a good tool and a buddy use to swear by it for his car

I got one unopened, still in the box i'll sell ya, let me know

stonemaster check your pms.

I didn't get to ride it really because it started to rain. Tomorrow I'm gonna put some miles on and see where I'm at. Heck, I've been riding around with no #2 (or intermittent) at idle, so I should notice a big difference with just getting that issue resolved. I think I might see if I can't send an email to the colortune folks asking them why my bike would run so different with their plug and if they have heard of this before/have any recommendations for it.

Since I tooled around with the colortune all day saturday, I think I might have trained my ear a little bit better for the "sweet spot"... so I have each of my around 2.5 turns out right now. I figure a bit rich is better than lean.

I really got the colortune for my 550... It's missing at WOT, and I don't know if it's too lean or rich, so I was hoping to figure that out. Also, I thought it seemed like a cool toy, so I had to have it. haha.

.

"i didn't say that it sucks just that it's overpriced"...
Never said you Timmy... :laugh:

Ok, something came to mind while reading this....

Questions:
When you had your carbs apart, had you noticed/recorded your jet sizes on each of the carbs?
I'm wondering if 1&2 have different jets in them....

"colortune folks asking them why my bike would run so different with their plug "....

Is the colortune running different when using in the Good cylinder/carbs as well or just #1 carb?

Are you running resistive plug wires?

Electrical (coils, plug wires, ignition I.E./points/condensers) checks/measurements good in comparing bad with good cylinder/carb combos?

Make sure the spak plug cap is making good contact for #1 for If I'm reading this correctly, #1 is pretty much the one giving you all the problems.... May be time for some new plug wires/caps....

Keep in mind all, this is a tool to help you jet your carbs as an aid in visually identifying issues, visually confirm the jetting/adjustments are correct for ideal combustion flames etc....

It's not going to do it for you.... :whistle: :laugh: :laugh: :laugh:

OMR to Plumm....
"Plum what you up to"

Plum to OMR:
"Re-jetting my Carbs"...

OMR to Plum...
"Oh, what's up with them"

Plum to OMR...
"Well I installed the colortune so drinking a beer waiting for this colortune to re-jet them carbs... Damn this is taking a long time for it's just sitting there... Not doing a damn thing..." :blink: :ohmy: :huh: :dry: :S :laugh: :laugh: :laugh:

gee OMR didnt think he was expecting the Colortune to do the work, or that he said such. My ? is wouldnt a simple reading of the plugs accomplish the same thing???

Not him where my joking reply was directed... I've had some PM's from various members on the Colortune recently due to concerns, if they got ripped off $$$, if the tool was worthless due to others comments...

Seriously speaking, I wouldn't promote a worthless tool.

The tool does what it's supposed to do... For those of us learning the art of carb jetting/tuning.... including me who don't/didn't have the experience or ear for tuning by ear.... taught me exactly what that meant as can be heard in the avi clip...

The tool also helped me identifying what was going on in my jetting (execessive carbon build up)... And yes as you have mentioned, Reading Sparkies Correctly is HUGE for that fact alone but doesn't really tell us what's occuring at idle for example or from idle to mid range....

Case in point, header pipe get's hot/warm but is it rich, lean... I screwed the pilot/air screws but carb still runs like crap/missing/carbon fouling etc... Or in T-shooting an issue such as this...

Watching as you turn you see no difference in combustion flame, well how much more easier can that be...

Ah well to each there own... worked for me and that's all I can report...

OMR, the bike ran differently on any cylinder with the colortune. I just worked with #1 the most, but they all did it. I don't have resistive wires or plugs, but resistive caps. I checked the electrical components not too far back and everything looked ok, but I can do that again. They all have the same jets in them too. Since I replaced the gasket maker on the #2 carb boot, all four carbs behave indentical, so #2 isn't a problem child anymore.

I realize it isn't going to do it for me
It just makes my wonder why it runs so crappy with the plug in.

Very weird indeed for I used mine on Gooses KZ1000 carb & sync tuning as well with no issues...

Another work bud used on his nova (Car) performance engine...

Definitely let us know what COlor-Tune replies with for others down the road....