Colortune Problem

I've been checking forums and found conflicting info. Colortune with yics or not? Set my pilot screws with a infrared thermometer, ran great. Just got a colortune to set more accurately. Set with colortune didn't really make a difference cylinders were blue, could not make any orange even 5 full turns rich. Bottomed out screw until I saw no color then opened and went right to blue and stayed blue no matter how far I opened them. Got to thinking maybe they need to be isolated with yics shutoff. Everything is synced and set just need info on yics and colortune. Reset with themometer, runs better. Don't think this is an air leak issue had the carbs off a few times and the inside the boots was smooth. Thanks. Sorry didn't think this posted so I hit post again

 

When you bottomed the pilot screw and then started opening it you should have first gotten a white flame for a lean mixture. Mine started to turn blue at about 1 1/2 turns and eventually got to the red/yellow/orange, or rich setting, certainly before 5 turns open. If you can't get a red/yellow/orange color at 5 turns it would indicate to me that the pilot system is not allowing enough fuel through. That could be that they aren't completely clean or perhaps a problem with the o-ring, washer, or needle. But it is strange that you would have the same problem on all carbs. Just for the heck of it, get it running and then slightly open the enrichment circuit and see if you get a red/yellow/orange flame. If you can't get it rich with the enrichment system then there has to be a problem inside the carbs. While the YICS may help it shouldn't be the cause of the problem you are experiencing.

 

do you have a stock exhaust and air box?
have you cleaned your carbs internaly ?

 

You can colortune without blocking the YICS ports. Not being able to go rich, or to start out lean indicates that there is a problem.

 

All stock, cleaned carbs. Enrichment on it will turn orange as it will with a blip of throttle. Yics tool in no change. If I go closed and open it's white then blue and will pop until rich enough. At first I was thinking I might have a air leak but then remembered these carbs are pressurized and air would be leaking out not in. Idles great anyway. I ended up with about 3 1/2 out. Thanks

 

Imho use the yics tool to isolate each carb in order to get them close (like bench synching for vacuum) and to determine if there's a problem with either one. Then remove the tool as k-moe advised and tweak them because they'll all use the yics port simultaneously.

Gary H.

 

you could have a vacuum leak its worth your time to do a propane test.
why do you think these carbs are pressurized? they are cv carbs and work by "vacuum" created by the engine.
the color tune is only adjusting your pilot fuel circuit. it is where you should be looking for problems?

 

Cleaned carbs how? Church of Clean clean?

Replaced throttle shaft seals? Given that the bike is now well over 30 years old I am starting to advise that all "soft" parts get replaced, even if they look good.

As XJ500 mentioned, we do not have pressurized carbs (the only pressurized CV carbs I know of are on aircraft). Here's a look inside: http://www.xjbikes.com/forums/threads/the-secret-life-of-carburetors.14751/

 

The Metro Turbo used a pressurised SU to good effect. It was an idea / application that had been around for years before Rover used it, but there were always drawbacks, and to put it on a car that was sold to Joe Public was just asking for bother. It was a device much more suited to tuners.

 

You may not have noticed but we're talking about a turbo. Has anyone colortuned a turbo? There are orings on the throttle shaft and starter plunger where they are supplied with pressurized air to prevent leaks. It is normal for air to leak at these seals. The fuel in the float chamber must also be pressurized to be metered to the venturiis. I have the original untouched carbs and new seals for a winter project. I replaced many parts on the ebay set I'm using now except throttle shaft seals. On the bs30 carbs fuel will begin to leak when these seals fail. Also if my carbs went to the church of clean they would be made pope. Thanks

 

Quick and clever... I like it.

Gary H.

 

Switching the color of your signaure from grey to red helps it to be seen. I completely glossed over the LJ designation.

Thinking about it you may not be able to tune it either lean or rich at idle. I'm not entirely sure why it is I think that, but I do.