colortune, colorblind or just dumb.

ok i bought one. when you do ajustments to the carbs are you using the synch screws to do it? or is there other screws that i'm so blind or stupid i can't find.

 

you do not use the sync screws. The adjustment screws are located on top of the carb, next to the outlet to the motor. If you have a "virgin", then they'll have metal plugs covering them.

 

Pilot adjust screws are on the top front of each carb. There may be a plug inserted on top of the screw(rubber or other) where you cant see it.

 

In this sectional view the pilot mixture screw is blue. The plug is yellow.

If the plugs are in there you need to remove them. Carefully drill a small hole off-center. By going off center you reduce the risk of damaging the screw.

Thread a coarse self-tapping screw (a drywall screw works well) and pull and wiggle until the plug comes out.

Factory setting of these screws on the 81 was about 1 3/4 turns from bottom.

 

Underneath the screw are (bottom to top):

O-ring
Washer
Spring

If you think you cleaned your carbs and you did not remove the screws and associated parts then your carbs are not clean.

 

(gulp) lol guess i never cleaned mine right, thanks MiCarl. i'll be pulling my carbs then. lol i sure missed up my synch now.

 

My statement WAS a bit strong.

Still, a good idea to get up there.

If you have to pull those plugs be VERY gentle. I drilled the one I removed the other with a very fine bit at a very low speed. People drilling the heads of those screws keeps Chacal in donut money.

Good news is you'll achieve Master status at getting those intake boots back on :wink:

Re-Bench sync while you have them off.

Now, to create more trouble: You did check your valve clearances?

 

Be really careful if you have to drill-out the Plugs.
The top of the Screw isn't very far (almost touching) the Plug's bottom.

You DO NOT want to damage the Wings or the Slot in the Pilot Mixture Screws.
Damaging the Screws means headaches you don't want or need.

I don't drill them out any more.
Instead, I put a small metal grinding bit in the wand of my Dremel and remove them like a Dentist working on filling a tooth.

Once enough material is removed you can get a pick in there and extract the Plug without damaging the Pilot Mixture Screw.

 

yeah i checked the valves yesterday, they were in spec. but i broke the gasket in one place. put some high heat rtv on the break that seems to be holding but it looks like it's leaking up front exhaust side. oh Micarl i replaced the carb boot and carb holder boots so it's pretty much a joy to pull apart now lol. brass plugs are out. now bench synch time.

 

And those donuts are darned expensive down here!

 

hummm i don't see alot of varation in the blue color workin left or right on the screw. but notice a bunch of difference in the sound of the bike when going left or right 2 down 2 to go.

 

I notice the same. I go from yellow to blue. Then the blue is there for a long time. I guess maybe it does start to look a bit white right before it starts to miss on the lean end.

 

Miks...if you're carbs are dirty inside then that could acount for the lack of responsiveness. Also, be aware that sometimes you have to move the screws quite a bit to get any color variation.....EXACTLY what MiCarl is saying above. It was quite surprising when I first used one of these to find out how much you could turn the screw and seemingly not have any effect. Don't worry, like teenage sex, it will happen eventually.......


Also, if you were changing the settings on the synch screws before you discovered the pilot (idle) mixture screws, then your synch is going to be way off and you're going to have to remedy that situation first........ :-(

 

hi Len the carbs should be pretty clean except for i never pulled the pilot thingie and shot carb cleaner through them. well awhile ago i pulled the carbs and put a rick o matic busness card bench synch followed that up with the famous rick o matic one gauge carb synch. doing the colortune now.

 

Nice to find a guy who ain't afraid to do the job "Old School"

Let's us know when you get it purring like a little kitten ... OK?

 

Hi Rick
i surely will get back with a short vid. i read that one post or yours or somebodys where ya polished the piston and bore on the carbs. i polished up the bore with 1000gt then finished up with 1200gt. worked up the pistons with some white diamond rouge they cleaned up really nice.

 

Used my Colortune a few weeks ago.

You might want to screw one of the mixture adjustment screws out to maybe 4 or 5 turns just to see the color change to yellow.

As long as you knew how many turns out you were to start with you can easily return to that setting.

I found it educational to see the full range of colors you can get from white > blue > yellow & back again. Also to hear the change in the sound of the engine when you get it correctly set.

 

There also seems to be some lag too. You turn it, it takes a couple seconds to catch up.

 

The "Lag" is like opening a micro-throttle. The Pilot AIR changes as more Air from the Pilot AIR Jet gets drawn-in to the Cylinder. Shortly thereafter, the change in volumetric pressure draws-up more Fuel; too.

Then, the Combined Air~Fuel Mixture reaches the Combustion Chamber changed. The Lag results from the change in Fuel Volume. You wait for it to increase when you enrich the mixture. You also wait for that which is present in the Passage to lessen when you lean-out the mixture.

Although the Tool is designed to show you a Bunsen Burner Blue for an IDEAL Air~Fuel Mixture ... Bunsen Burner Blue might NOT be the IDEAL color you NEED ... depending on the condition of the Engine.

Factors like: Compression, Combustion Chamber and Piston Crown cleanliness, Valves and the percentage of Ethanol in the Fuel will cause the Flame to change color without appreciably adjusting the Mixture Screw.

High percentages of C2-H6-0 added to the Fuel vary in ACTUAL Percentage.
The percentage posted on the Pump is supposed to be the HIGHEST allowable percentage. It MAY be more or less depending upon where you are geographically and the formulation of the Fuel for seasonal distribution.

The pretty BLUE might be LEAN if the Gas has a good share of Alcohol in it!

Last Summer I ran High Test Gas rather than Regular because the Mixture was such that I was getting "Knock" out of the Regular Gas.

If you hear your Engine "Pinging" because the Fuel is causing detonation ahead of the spark ... get some High Test Gas in there PRONTO!

Pre-ignition knock will damage your Pistons faster than you can cut your seat in half with a Chain Saw.
The Pistons can't handle it.

Something GOT to give!

 

ok short vid of first round after using colortune. i figure doing a second round after i do a short trip and see what the plugs look like.
hummm didn't work . so i'll work on getting it to work sorry.
http://s160.photobucket.com/albums/t190 ... V00001.flv

 

so i went for a short ride yesterday noticed from 1000 to 2500 seems slow to rev. 2500 an up runs like a scalded dog. reading in the manual it says engines before 1985 should be set halfway between the point where yellow flame disappears and the point where the engine speed falls slightly. hummm well i didn't do that lol. i suppose that could be a problem. book also says around 5 mins max for the tool being installed and running. bout how much time is everyone spending per cylinder how many revs are you running it up to during session?

 

ok just had time yesterday to run back through the carbs. #4 carb is the only one that i can turn the ajustment screw that has color change from orange, yellow to blue. the other 3 ajust colors seem to be green blue, blue either way i screw the ajustment the bike runs better or starts crapping out. hummm guess i'll pull the carbs and try cleaning the pilot outlet now i know they are there.

 

You have to remove the Pilot Fuel Jet from the bottom and the Pilot Mixture Screw from the top.

Spray-out the Passage.

Then, fill a Rubber Ear Syringe and Flush-out the Passage.

Insert Syringe Tip in Pilot AIR Jet and block-off Pilot Mixture Screw Hole
(Back-flush)

 

ok i pulled the carbs, tore them down pulled the pilot mixture screws, pulled main jets, pilot jets, float needle seats, pulled the jets up top and spent an hour spraying every passage top and bottom i could find with seafoam deep creep let it set for 10mins blew out all the carbs. seafoamed one, more time. blew them out put them all back together stuck them on the bike. started colortune carb1 still had the no color ajust other 3 worked perfect.
pulled the carbs again tore into carb1 hit it couple more times with the seafoam blew it out put it back together. put the carbs on the bike. started colortune on carb1 it started doing a color change so i went through all the carbs and set them to where the yellow just changes to blue. i started a second round when i started in on carb1 it wouldn't color change again. so i set it to where it sounded the best then checked the rest and set them the same as above. bike runs great no stumbling when rolling on the rpms. anyone with a 81 maxim colortuning are you doing it like i'm doing or are you tuning it different? i was thinking maybe adding seafoam motor treatment to the fuel but how much do you put in a tank full?

 

Something was/is still clogged or wrong inside carb #1...float levels, plugged passage, stuck float, etc. Hopefully it something temporary and flushed itself out.

 

I'd make sure you have the right Pilot Fuel Jet in that Number-1.
I can't read the numbers without a magnifying glass.

As far as the Colortuning goes ...

I start-off by Bottoming-Out the Pilot Mixture Screw and bringing it Out to the Factory Pre-set of 2-1/2 Turns Out.

Then, I run-it and begin the Colortuning.
Watching the Burn ... I turn the Pilot Mixture Screw Out until I get the BLUE and KEEP GOING through the Blue into where the Blue goes away.

Then, I tweak the Pilot Screw back-in ... s-l-o-w-l-y ... until I get the Blue BACK!
That ... is where you want to be!