eratic high Idle question

Ok so I probably spelled "eratic" wrong. moving on
the bike is finally running, sometimes the idle will want to climb too high. don't know how high cause at 4-5,00 I cut it (dont want to break anything).
the throttle cable is free and has a "tad" of slack at throttle full forward. choke cable doesn't seem to be holding the choke open . The bike is not vac synced yet wuold that be the problem? done this 7 of the 12 starts the bike has had. never let it run more than 30 seconds except 3 times, one of wich was a 700 foot ride out to the end of the street and back. vac leak maybe?
Tell me if I'm wrong but I feel and hope its just out of sync as yet.
bike was TORE DOWN. valves in spec, CLEAN carbs, float levels VERIFIED correct. No hole or cracks in manifold boots or airbox boots, engine ALL stock

 

This might be a dumb question since you said they're clean, but have you tried the screwdriver trick on the carbs just to be sure? While it's at high idle, tap the carbs with the handle of a screwdriver fairly hard and see if it drops back down. It's truly unbelievable how finicky the carbs can be. I was sure mine were clean the first time I did it and then I tried tapping on them and sure enough... they were sticking a little.

 

hey i'd put a hershey bar in the tank if I thought it would work. sure I'll try it thanks.
still fires up easy! loving that never even hear the starter. do gotta adjust the clutch though cause it engages right off the release about quarter of the way out.

 

Do your vac sync. That may fix it. Or it'll at least help.

You're not done tuning. At 4/5K you've got a butterfly open and it's drawing main jet fuel. Get the vacuum sync done and bring the idle down with the big knob in the center. Hopefully when you bench synced you left enough adjustment in it to bring the idle down.

 

yeah I got room to go either way on that. I just gotta vac sync bad. Before it starts to climb the tach is"jumpy between" about 1400 and 2100. maybe not that extreme but it's close. I hadn't "tuned" anything yet I thought I had to sync first? I just bench synced, set the pilot mixtures at 3&1/2 out from soft bottom, and set float levels then verified by fluid(on the bike).
After verifing fluid I finished the battery charge and touched the button, she fired right off. I'm really feeling the vac but you think I should get at some tune first?

 

pilot mix should be 2.5turns to start.

The Vac sync is part of the tuning along with Idle mix adjustments.

 

10-4. I'll go out and mess with it some more in a little while and report back. And thanks man.

 

A vacuum sync isn't "messing" it's a real procedure.

You need some form of manometer; it can be two baby bottles, a 4' hunk of clear tubing tied to a yardstick, or a 4-tube Morgan CarbTune Pro (yeah, baby!) but you need a way to compare the manifold vacuum from each cylinder to its neighbors and adjust accordingly.

"Messing" will just drive you further away from sync'ed.

 

yeah I meant taking the idle mixture screws back in one turn so they are starting at 2 1/2 instead of 3 1/2. I was looking at ordering the morgan, iy's like 100.00ish? how do I build the baby bottle thing? I hate going to a shop but there is a bike guy that just opened up about 1/2 mile from me said he would vac sync me for 60.00. but im fuzzy on procedure here. what are the steps to do this? I can get this done for me but if I have it done I still wont know how to do it

 

search this site for sync tools and method. It's been written dozens of times usually in the same threads.

You can build your sync tool for $4 (yard stick and tube) and it shouldn't take you more than an hour to make the tool and sync the bike, beer time included.

 

sweet. thanks and now off to the search.
side note Id rather work on my bike than drive my van.

 

ok so I need to get 3&4 together then 1&2? then 2 to 3? and can I just turn the knob to idle it down a bit so I can do this without it going to a million rpm's or should i rich the mix a little? the tube and oil I can do- I get that. I get 3&4 first since 3 is static. I must seem a little retarded right now but I get the idea just want to clarify procedure and what about this mix? do I need to adress that or just "knob" it down and start syncing?
and I will use fans

 

Hey Shane,

Give me a call and I can talk you through the syncing stuff.

Dave Fox

 

as always Dave you are the man. Im gonna have to add your name to the title! I'll take you up on that