Jet size question

Oljo here with another question.Bike,1980 750 ltd twin bs38's. Im still tryin to dial in the right combination on these carbs.They have 125 main jets and 45 pilots.It really takes a while to warm up and idle on its on.Would a larger pilot help maybe? If so,how much larger should I start with.To ride I usaually run the idle screw up so I dont have to sit and rev on it and after about 7 to 10 minutes it will start picking up faster on idle,then I run it back to ride. I havent did the chop test yet,but right now when I shut down the plugs are white on the tips and about halfway down turn to carbon black.Any ideas? Thanks

More heat is associated with going lean, potentially dangerously so. So conversely being rich will be a bit cooler. Bright light on a close up pic of the plugs would help.

I am trying to get a picture.My phone is all I got.Not getting a clear picture.I'll keep trying.Today the plugs are both black.When I adjust the air fuel mixture screw to where the idle is really smooth sounding,good solid rumble,it wont run out good without stumbling and spitting a little bit.Sometimes I can throttle to get it back and some times I have to back off.I am assuming the only air fuel mix screw is fuel .Can you enlighten me on that?When I stop to adjust I'm always backing off to get it to run out on the road. Then that gives it a rough idle.In a nut shell if I have good idle it doesn't want to run good.If I set it to run better, I don't have good idle.Setting the air fuel mix screw that is.

Black plugs again suggest fuel that hasn't burned. Poor spark, lack of air or too much fuel. I may not be the guy to help you because my approach is to tear everything apart and get it right instead of trying to find the needle in the haystack. My sense is you have carb contamination issues. Idle circuit is the job of the pilot circuit You seem to have issues when you engage the next circuit in the carbs off idle. That points me to removing and ultrasonic cleaning the carbs. Then syncing the carbs after install. Do you know where the valve clearances are set? Valves adjusted, cams timed properly, and clean carbs adjusted and synced should get you home but I tend to build things foundation up. All of this ignores the spark side of the equation. Points or electronic ignition?

Does your spark advance work properly?
Steve

It seems to make a difference when I moved the points plate.I don't really know how to tell if the spark mechenizm behind the plate works.Can you tell me how to check it?

Take the plate off clean and lube the cam with grease. A few drops of oil on the springs. The cam should move freely.
Steve

Thanks,I'm gonna look at it today and get a little lube on it.When I first brought the bike home the clutches were stuck so I tried to get the cover off to clean them and wasn't able to get the plate completely off because I didn't want to disturb the advance.I 'm still not sure how to get the thing off to be able to remove the cover plate.I was able to get some lube in on the plates and freed the clutches up.Thanks again for the pictures.I hope I didn't disturb it some how.Is it common for these engine's to be this cold natured?Although it fires right up,I run the idle up to warm it up,then when it'll hold it's own I run it back down a little. A piece of info I haven't mentioned, one of the floats had gave it up at the solder and had broke down to the point of no repair,the side it was leaning on while setting up.I went to the shop that handles salvage parts and found some floats that would fit but they were plastic instead of brass.I've synched the butterfly's and adjusted on the floats a few times getiing them pretty close to each other.Any problems replacing the floats in these carbs with plastic?They don't seem to be sticking,or overflowing,unless I forget to turn the gas off!.Any time I try the choke it kills it pretty quick.I cant use the choke to idle it up.They seem to be moving freely.I haven't broke the choke's down when I had the carbs off anytime.I don't know what to expect in there.

Hawk,,No I haven't did valves yet. I want to learn a little more before I try I would like to do em myself, So you are saying I am running lean most of the time?Should I be running My air fuel screw in or out to get more gas flowing?I just have the one screw on each carb?I can stop and adjust em to get ti to run out better.But when I get em there the idle is real rough.Points to answer your question.Just one set

If your valves are out of adjustment you will never get it to run right.
Steve

I think I'm going to find I have the barrel type from what I've read and seen.I'm pretty sure I can get the shims I need from the local Jap bike mechanic,just waiting for bad weather I guess.Gonna do some more research on em in the meantime. It looks like the tricky part is the cam chain.

Here's a pretty clear picture of the spark advance,A lot of wear on the one side and the springs are a little loose.I dont really understand what this does for it.Does it look like it could cause trouble? I'm gonna try to find a picture of a good one.