Signs of bad carbs?

[dlebe250]

Hey guys, so recently my bike has been acting up. It will start up then the moment i decrease the choke it dies. My question is what types of signs will carbs that need cleaning show? I made it down the block and then it died, and wouldnt start up again. I had to walk it all the way back, pretty embarrassing. It's been quite a pain starting this bike too, my mechanic said these bikes are "cold blooded" and tend to be a pain to warm up. The temps around here are 40-50F. Thanks for the input.

[Chubbs032]

how long u leave the choker on

[kkim]

will it ever warm up to a point where you can turn off the choke completely and have the bike idle nicely w/o any choke at all?

if not, most likely your pilot jets are clogged and the carbs need cleaning.

[mrlmd]

Signs of a dirty carb - From another forum I frequent:

http://www.youtube.com/watch?v=obXYv...layer_embedded

Does yours do this?

Before you decide to take it apart, run some Seafoam or Berryman's B12 Chemtool (cheaper, 1/3 the price) in the gas and see if it will clean it out.

Are you turning the choke down right after you start it or are you riding it and letting the bike warm up before you slowly turn it down?
You may not be using the choke correctly as well as have another problem.

[dlebe250]

Chubbs- It varies how long I leave the choke on. Never left it on longer than 4min. I try to decrease it in small increments but I slight touch on the choke and it loses rpms and dies.

kkim- It used to do that but just recently it died during a ride when it was already warm. Then I tried again a day or two later to start it up and go for another ride and couldnt. It started but then died. I restarted it with full choke and it started up, was around 5k rmps and i tried to decrease the choke a tad and it died. So I tried riding it with choke on to warm it up (easy riding) and the moment I came to a stop it died and wouldnt start up again. It's quite frustrating because I can't seem to think of any reason for it to do it other than a possible carb cleaning, which I dont even know if it is that.

Also, around what rpm do you all keep it at while warming up? I read somewhere that you should ride it, so when it warms up it wont get any "hot spots" and itll warm up evenly. Is this true?

[dlebe250]

Marc- that video was pretty helpful, thanks. It somewhat acts like that now except it dies quite often. My best guess is that it needs a cleaning.

[Chubbs032]

wats your idle rpm set at after it's warm ?

[dlebe250]

its around 1200/1300

[Chubbs032]

it should be ~2000

[kkim]

Originally Posted by dlebe250

its around 1200/1300

I have mine set at 1500 rpm.

[mrlmd]

Originally Posted by dlebe250

its around 1200/1300

That's correct, and if everything is working, that should be OK.
Try the carb cleaners in the gas before you start taking things apart.

[Jinx250]

This is a sign of one or two things - dirty carbs, tight valves. Carbs are the easiest fix, as long as you clean them properly. For your symptoms, if it's carb related, running the cleaner in the gas will not work, becuase the passages in the pilot jets are so small, nothing gets through, hence the stalling. If your carbs are clean then check your valve clearances.

[mrlmd]

Again, from another forum.
I would try this first before removing the carbs. It's a lot easier and much less expensive, especially if you have to pay someone else to do it, and it may work and solve the problem. If it doesn't work, you didn't lose anything except a little time.
So here goes:

This guy right here had a question about a bike that had sat up for a long time, I have been meaning to post this procedure for a long time, just hadn't got around to it, so here it is....


First off, this is not a guaranteed cure for anything, and should only be done if you already have a problem, this most definitely shouldn't be done as a regular maintainence procedure, but it worked like a charm for me. I am going to describe how to do this to a GZ, even though that is not the bike i used it on, so bear with me.


Go buy you a can of Seafoam, it may or may not work with a different cleaner, but Seafoam specifically states you can use it in this way, so i would use it, and also go buy two extra spark plugs for your bike, you may not use them both, but it never hurts to have an extra one laying around especially when dealing with a single cylinder bike.

In this case since we are dealing with a bike with a gravity fed fuel system (my VS800 has a fuel pump, so the procedure is a little different), your going to have to drain your gas tank (if your carb is gunked up you would want to do that anyways), once you have your tank completely drained, take and pour the entire bottle of Seafoam in, and then turn your fuel petcock to prime, then crank your motorcycle up and let it run until it dies (and it eventually will), then crank it back up a few more times just to make sure everything is soaked in Seafoam, at this point take your spark plug out as it will be fouled, let it sit for an hour or so, come back out, drain your gas tank, drain your carb bowl, put in some new gas and a new spark plug, crank it up, be ready to ride it right then cause it is probably gonna run like hell for a few minutes, mine smoked like hell for about half a mile, then it felt like a brand new bike the way it ran.


In the case of my bike, I was able to introduce Seafoam into my fuel system straight from the can because I have a fuel Pump, I took a long piece of fuel hose, shoved it in the can of Seafoam and ran my bike until it quit and cranked it back up and did it again a few times, until it just completely fouled the plugs. then i went in the house for a few hours came back out hooked my gas tank back up, drained the carb bowls, put in new plugs and rode the crap out of it, it blew out all kinds of funk out of the tailpipes, but it was a different bike after about a mile or so.


Like I said, this is only for extremely dirty carbs, and you don't want to leave it soaking for more than a couple of hours or so, and it may or may not work, but it will only cost you about 10-12 bucks and a couple of hours to try it, and it is guaranteed to at least make your fuel system cleaner than it was, and you will have a new spark plug, even if it doesn't solve your problem.

Also pay close attention to what comes out of your gas tank, if it looks extremely dirty inside of it, you may want to take gas and shake it around inside your gas tank and dump it out a few times before you do it, so you don't just reintroduce more dirt into your carb.

So there is my backyard fuel system cleaning method, this would be especially good for someone who doesn't have the know how or the tools to take apart a carb and clean it, and a good cheap last ditch effort before paying a shop to look at it.

[dlebe250]

Alright thanks guys, I'll let you know what my results are. The help is greatly appreciated.

[K-Dag]

My '02 does this terribly. I've learned to deal with it, which usually means:

1) Starting with the choke all the way on. Sometimes takes a couple starts, but only if it's been sitting a week+. I do this before I even put in my earplugs, don my helmet and gloves, and hop on. It needs a good couple minutes with the choke on all the way. When I get on, I see if it will still keep going if I very slightly push the choke back. Mine, too, is extremely sensitive. Practically binary.

2) Leave the choke 3/4 on for usually 5-15 minutes, depending upon how cold it is, how long the bike had been sitting.

3) After that amount of time, I find that I can turn off the choke once I'm at speed, and then I just keep an eye on the RPMs when I come to stops, revving the engine if I need to to keep it from dying.

I'm pretty sure my bike shouldn't be *this* cold-blooded, but as I said, I've just learned to deal with it, and it's given me some far worse problems

Do your bike's RPMs ever randomly climb when your hand is off the throttle/choke? Mine will randomly do this, and the idle speed seems to actually stay higher if I've had the choke on for a long time. I think this is another problem with my bike, but again, no leads.

[dlebe250]

Originally Posted by K-Dag

My '02 does this terribly. I've learned to deal with it, which usually means:

1) Starting with the choke all the way on. Sometimes takes a couple starts, but only if it's been sitting a week+. I do this before I even put in my earplugs, don my helmet and gloves, and hop on. It needs a good couple minutes with the choke on all the way. When I get on, I see if it will still keep going if I very slightly push the choke back. Mine, too, is extremely sensitive. Practically binary.

2) Leave the choke 3/4 on for usually 5-15 minutes, depending upon how cold it is, how long the bike had been sitting.

3) After that amount of time, I find that I can turn off the choke once I'm at speed, and then I just keep an eye on the RPMs when I come to stops, revving the engine if I need to to keep it from dying.

I'm pretty sure my bike shouldn't be *this* cold-blooded, but as I said, I've just learned to deal with it, and it's given me some far worse problems

Do your bike's RPMs ever randomly climb when your hand is off the throttle/choke? Mine will randomly do this, and the idle speed seems to actually stay higher if I've had the choke on for a long time. I think this is another problem with my bike, but again, no leads.

Yeah sounds like we have a similar issue. I have a mechanic checking it out right now, I'll let you know what he thinks is wrong (if anything). It's pretty annoying being uncertain that you'll bike will start or not, let alone embarrassing. Personally, I want to get this fixed because an unreliable bike is not a bike worth having IMO. Pretty sure it's a fueling issue but as you can tell im a newbie too.

My RMPs don't randomly climb when my hand is off the throttle, if you watch the video above it may certainly be your carbs thats the problem. My bike sometimes if not warmed up will die out on the road and will pretty much not turn over again-which involved me walking her home.

I really dont mind having a mechanic look at it b/c I dont have the tools or knowledge to work on it yet. Plus my mechanic is really laid back and is very fair with pricing. The only downside is being a college student so money is scarce haha.

[Jinx250]

Originally Posted by K-Dag

My '02 does this terribly. I've learned to deal with it, which usually means:

1) Starting with the choke all the way on. Sometimes takes a couple starts, but only if it's been sitting a week+. I do this before I even put in my earplugs, don my helmet and gloves, and hop on. It needs a good couple minutes with the choke on all the way. When I get on, I see if it will still keep going if I very slightly push the choke back. Mine, too, is extremely sensitive. Practically binary.

2) Leave the choke 3/4 on for usually 5-15 minutes, depending upon how cold it is, how long the bike had been sitting.

3) After that amount of time, I find that I can turn off the choke once I'm at speed, and then I just keep an eye on the RPMs when I come to stops, revving the engine if I need to to keep it from dying.

I'm pretty sure my bike shouldn't be *this* cold-blooded, but as I said, I've just learned to deal with it, and it's given me some far worse problems

Do your bike's RPMs ever randomly climb when your hand is off the throttle/choke? Mine will randomly do this, and the idle speed seems to actually stay higher if I've had the choke on for a long time. I think this is another problem with my bike, but again, no leads.

You know, if you're not willing to work on your carbs, you should find someone trustworthy to do it. There's no reason to leave your choke on that long, and the fix is really very simple. There are a couple of guys on the "other" board in SoCal who might be willing to help. One of them is the one who tuned my baby, and she's rock solid.

[dlebe250]

Alright so my mechanic checked my bike out and he found that one of the lines to the fuel tank was plugged. He unplugged it but a new line on. He also mentioned a fuel valve or something that recycles unused fuel back into the engine was gone or not functioning right. He said when he was checking it out the fuel was coming out slowly and then barely at all. (not sure where this was happening but he started mentioning things about how the carbs didnt have enough fuel in them and what not. Anyway he told me to ride it around for a week and see if I still have issues with it. So far it run's A LOT better. To me it's almost like a new bike. Runs smoother, sounds better, and maxes out at around 106mph, previously it was around 90.

Sorry this description sucks but hopefully it gives you an idea of what was wrong.

[mrlmd]

Glad you got it fixed and are happily back on the road.
Sometimes a little professional help goes a long way.

[fjyang]

Originally Posted by Jinx250

There's no reason to leave your choke on that long, and the fix is really very simple. There are a couple of guys on the "other" board in SoCal who might be willing to help. One of them is the one who tuned my baby, and she's rock solid.

Do you mind sharing whats your simple solution for the "cold blooded", irratic idle, stalling when cold symptoms that pretty much share by all 250's when they left the factory?

I'd clean my carbs, pilot jets and turn the idle mixture screw 4.5 turns out and the problem presist. Per my conversation with Keary from Area P, after you turn the mixture screw 3 turns out, your pretty much out of adjustments so I up the size of my pilot jet and it make a big difference right away. Its easier to start and won't need to full choke to ride for the first 10 min. and a lot easier maintaining idle when engine is still cold.

So bigger pilot jet works for me but I like to hear what others have done to cure the "cold blooded" symptom.

[demp]

Originally Posted by mrlmd

In this case since we are dealing with a bike with a gravity fed fuel system (my VS800 has a fuel pump, so the procedure is a little different), your going to have to drain your gas tank (if your carb is gunked up you would want to do that anyways), once you have your tank completely drained, take and pour the entire bottle of Seafoam in, and then turn your fuel petcock to prime, then crank your motorcycle up and let it run until it dies (and it eventually will), then crank it back up a few more times just to make sure everything is soaked in Seafoam, at this point take your spark plug out as it will be fouled, let it sit for an hour or so, come back out, drain your gas tank, drain your carb bowl, put in some new gas and a new spark plug, crank it up, be ready to ride it right then cause it is probably gonna run like hell for a few minutes, mine smoked like hell for about half a mile, then it felt like a brand new bike the way it ran.


In the case of my bike, I was able to introduce Seafoam into my fuel system straight from the can because I have a fuel Pump, I took a long piece of fuel hose, shoved it in the can of Seafoam and ran my bike until it quit and cranked it back up and did it again a few times, until it just completely fouled the plugs. then i went in the house for a few hours came back out hooked my gas tank back up, drained the carb bowls, put in new plugs and rode the crap out of it, it blew out all kinds of funk out of the tailpipes, but it was a different bike after about a mile or so.

Hmmm, I might try this method