fuel system help 1990 xt 600

[njenduro]

I have had this bike for about 6 months now. When I bought it needed new intake gaskets and intake itself they had the wrong ones on there don' t ask.I also took the carbs apart and put new o rings needle valve etc. and cleaned the carb out. Now my problem is when I cruise around at 25 35 she gives a little hesitation but she puuls great and rides great at higher spead and cruises great on the highway. Also she starts great at cold and warm but did noiticed that if she is in idle and I give it a quick hit with the throttle she will stall but will start back up help is needed thanks again

[steveloomis]

Have you adjusted the fuel screw at the front bottom of the primary carb?

[njenduro]

Yes I did which is a pain and burnt fingers too is there a easier way with a tool

[steveloomis]

Just a short screwdriver....

[njenduro]

Which way do you suggest to go in or out thanks

[xtrock]

First all the way inn, then 2,5 rounds out.

[bacardi23]

count the turns you go in! and don't tighten it or you'll break it!!

[jjrider]

Often a stutter when giving throttle is the needle circuit. The slide opens up but gas takes a second to catch up. I'd raise the needle one clip after verifying mixture setting. Borderline lean pilot jet will make it worse.

[njenduro]

I did purchase new jets and did put everything stock and did turn the screw 2.5 turns out . I will try to adjust needle up one also what should I use to raise the needle thanks.

[jjrider]

If your needle has multiple groove you move the clip down one groove, if ther is no grooves like mine I had some thin washers that I put underneath the clip when in the holder. Only needs to be .015"-.025" thick.

[njenduro]

Would it be easier to take carb off or can I leave the carb ? Also when cold start she takes time to warm with the choke on only. After warmnup she runs good even when after running and sitting for about 1hr and hot outside I have to choke then ride push choke in goodvto go maybe same problem thanks again

[jjrider]

Sounds good. It should need choke to start and warm up for a minute or two. Much more than that it may be a sign of running lean. Did you take the spark plug out? What color was it. To check the needle you may be able to leave the carbs on the bike. Just take the tank off and most bolts should be right there, I used a 90 degree screwdriver for some of mine on the secondary.

[njenduro]

maybe I will raise the needle and leave the air mixture alone cause that might richin it up allitle. For the plug drive it then check correct? Thanks

[jjrider]

For best results go for a drive and hold the throttle steady at the rpm range you want to check.(18k to2000rpm,then 2500rpm, then 3000,even 3500rpm) Drive for 2,3, even 4 miles/km like that, then quickly pull in the clutch and shut the motor down(before even stopping if possible). Pull the plug and look at the color.

It should be a light grayish or light tan color. If white or real light colored it's lean, dark brown or black= rich. You can do that at several rpms to get a decent idea of what's going on. It is also best to start with a new plug or one that is cleaned. An old tarnished plug may not be as accurate.

This isn't a do-all /end-all way to know just what is going on but it is pretty good for getting close

[steveloomis]

Actually this is a very GOOD way to check your mixture. It is called a plug chop and your spark plug never lies. Use a fresh plug so you can read the color correctly. Only better way is to use an o2 sensor or EGT (exhaust gas temp) gauge but either is expensive so the old plug chop is your friend. Just buy several new plugs to throughly test thru the ranges.