Rpm Go to 5000 when i turn off choke.

When i turn the bike on it starts, but the rpm fluctuate a little bit. When i try to turn off the choke it just races to 5 or 6000, and i either have to kill it or turn down the idle screw. The boots don't have any cracks, What could be causing this?

should this be in carburetor section>

JaimeMs wrote: When i turn the bike on it starts, but the rpm fluctuate a little bit. When i try to turn off the choke it just races to 5 or 6000, and i either have to kill it or turn down the idle screw. The boots don't have any cracks, What could be causing this?

Possibly an air leak somewhere else other than a cracked carb holder.

What intake air filtration is fitted, if any, pods or stock air box or none?

Good Fortune!

As Patton mentions the simplest possibility is an air leak somewhere, boots don't necessarily have to be cracked to leak, My 750 did the same thing after it warmed up , drive it a couple miles and it would rev in the same manner as yours. I found I had both air leaks past the rubber manifolds between the carbs and engine and tight valve clearances on the intake cam.

i just did a valve adjustment and since it was my first time i had someone double check so im sure that isnt it. And this was happening before the valve adjustment. The air box was missing when i got the bike so it is running on pods.

It's sounding like an air leak.
Tell us more:
-Did the bike ever run properly?
-Any other changes made to the fuel/air system (hardware changes, adjustments, and the like)?
-Have you snooped (used a substance like carb cleaner) to look for any vacuum leaks on or around the carbs yet?
-Can you get it to idle with the idle adjustment all the way out?
-Is it popping or backfiring?
-If so, when? While it is idling or when you rev it up or down, or both?
-Have you messed with the throttle cabling in any way prior to this issue?
-Have you ever synched the carbs?
These are not suggestions for troubleshooting, just need some background.

DiamondSkyBlue1000 wrote: ...Have you snooped (used a substance like carb cleaner) to look for any vacuum leaks on or around the carbs yet?....

An excellent testing technique.

With engine at idle, spray carb cleaner or WD40 around the carb holders, vacuum nipples, all vacuum tube connections (including vacuum petcock if fitted, and clear air injection paraphernalia if fitted).

Listen for any change in rpm resulting from the spray.

Watch for emission of any exhaust smoke resulting from the spray.

Change in rpm and/or exhaust smoke indicates ingestion of outside air into the fuel mixture through a leak from somewhere.

Good Fortune!

First things first, address the items in my other post to avoid missing something and wasting a lot of valuable time that could be spent riding. Hate to see you do a lot of work only to find out that you had left a hose disconnected or the throttle cable was now getting hung up somewhere after the valve clearance check was done.

Just a couple of quick tips on leak checking if it comes to that:

Go slow, don't hose the whole thing down. You won't be able to pinpoint the leak locations if you spray and pray. Spray a small location and wait. You may have several small leaks instead of one big one. Small leaks take time to allow your snoop to get into the intake stream and give you the resultant change in RPM.

Use small amounts. If you spray too much, it will find its way into the air intake of the carb (especially true with pods) and give a false reading (or "hit" as it's called). The little swizzle stick tube that you put in the spray nozzle of the carb cleaner can is your friend here.
Your engine will react differently depending on what you use as your snoop. Get your idle down as low as possible and spray some on one of the pods. Observe the reaction. That's what you'll be looking for when you are snooping.

Fix the leaks as you go! This may seem a bit of a time waster but it's not. If you get a hit on a boot, for instance, make sure it's on tight and not hardened. If you can't get the leak to go away, replace it. Chances are if one is shot, they all are. Just replace them and start the snoop again. I've had boots simply fall apart in my hands that were only about 2 years old! Ethanol was probably the culprit.
You can't snoop the pods! Think about it. But, if your pods aren't sealing properly around the carb mouth, it'll cause problems.

Once you can snoop all around all of the carbs with no hits, then it's on to step two. Don't rush.
If you find leaks and you correct them, then you will need to synch the carbs. It's a good bet that if someone synched them before with vacuum leaks present, you are going to have one carb that is now pulling a high vacuum in relation to the others and you'll have a rough, erratic, growling type of idle. Pulling away from a stop will be an art form. :laugh:

we did sync the carbs with vacuum leaks present. It wasn't nearly as noticeable then. just a slight fluctuation.
At this point im having a difficult time just getting the engine started. i just went out to take out the battery to charge it and use a little more sealant when i saw a missing screw on the bottom of the right boot. Not sure if that screw hole leads into the intake or if it is separate. yesterday i sprayed some carb cleaner on one of the carbs by the boot and it completely bogged down. I thought it was going to die so my instinct had me pull on the throttle, which killed the engine, of course. I dont have an impact driver and those screws are on super tight so i cannot get the boots off to look at yet. But after using the sealant in this area i still had the problem. Must have looked right past the screw hole. Hopefully This is it and when my battery completely charges ill see if i can start her up.

Background info.
The bike was running for a few years before i bought it, although not taken care of at all.
We did a carb cleaning, the o rings were not replaced, so if i cannot find this leak ill take a second look at them.
It is not backfiring
I did adjust the throttle cable recently but i think the leak was there before, although not as bad.
The carbs were synced right after cleaning them
The right exhaust pipe was kicking out a good amount of smoke a few days ago, but has since stopped.

JaimeMs wrote: we did sync the carbs with vacuum leaks present. It wasn't nearly as noticeable then. just a slight fluctuation.
At this point im having a difficult time just getting the engine started. i just went out to take out the battery to charge it and use a little more sealant when i saw a missing screw on the bottom of the right boot. Not sure if that screw hole leads into the intake or if it is separate. yesterday i sprayed some carb cleaner on one of the carbs by the boot and it completely bogged down. I thought it was going to die so my instinct had me pull on the throttle, which killed the engine, of course. I dont have an impact driver and those screws are on super tight so i cannot get the boots off to look at yet. But after using the sealant in this area i still had the problem. Must have looked right past the screw hole. Hopefully This is it and when my battery completely charges ill see if i can start her up.

A loose, missing, stripped, or snapped-off carb holder screw would likely cause a carb holder to leak, even a brand new carb holder.

The carb holders should NOT look like any of these wretched examples:



Sealant won't last long in this area.

Good Fortune!

Well, that's something. Someone probably cranked those screws down trying to remedy a leak. Hopefully, that missing screw isn't because it's broken off. When you replace them, use Allen head screws. The OEM screws aren't actually Philips head, they are a special Japanese type that use a screwdriver made for them. You can't get good torque on them using a Philips screwdriver.

Anyway, can't get her to start. Once you get a hot battery, try again. If no luck, try spraying starting fluid into your pods. If you have spark, it will fire for a moment. If it dies right away, you got a fuel problem. If you have trouble getting her to even fire with starting fluid, your plugs are fouled which is my guess. Pull those out and check them before you do anything else.

When you synch the carbs, you will see some bobbling of the fluid in the tubes, that's normal. Is this the fluctuation you mentioned? The idea is to get the levels as close to the same height as possible although it doesn't have to be exact. The fancier carb sticks have little restrictors in the tubes to minimize the bobbling.

If your carbs are super out of synch, yes it won't start. On the synching screw for the carb that had the missing screw try adjusting it one way then the other while trying to start it. You might get it close enough to fire. Most likely you closed the leak enough and now that carb is pulling massive vacuum relative to the others. That means they won't be pulling enough vacuum to work. Yes, they are relative. When you do synch them without leaks, adjusting one will have an effect on the others and you can adjust them so much that you kill the motor.

If this doesn't work, you will have to bench synch them to get close enough to run. Then vacuum synch them. I'm guessing it won't get to that, though.

First things first FIX THE LEAK! or you are wasting your time. Don't give up!

Oh yeah, almost forgot, if your bike has a vacuum petcock make sure that's working or you won't be getting fuel to the carbs!