Hi guys, recently I've been noticing some odd behaviour when cold starting my bike:
1st start today, this morning, bike left sitting in garage overnight (fully cold): Not too hard a start, but I had to give it just a bit of throttle for a half second after hitting the starter to get it to keep an idle. This has happened a couple times over the past week, usually right in the morning. Also, choke is responding unevenly: first quarter turn DROPS the revs slightly, next quarter then brings them back up to where they were, and after that it goes up at a pretty normal rate. Choke left half on (around 2000 RPM) for maybe 6 blocks after riding off, until bike will idle at about 1300 (little high?) without choke.
2nd start today: same as 1st start, needed just a touch of throttle - not as much choke needed, just a bit, left on for a couple of blocks after starting off.
3rd start today, couple of hours ago, bike left sitting for maybe 3-4 hours-ish after coming home from work (semi-cold): harder start, more throttle needed, only got it going on the second try by holding the throttle for maybe 2 or 3 seconds. Choke response seems even more wacked out - first quarter drops RPM, next quarter goes up, third quarter isn't much different from 2nd and turning it the final quarter turn outwards will actually DROP the RPM again and reliably stall the engine.
On the most recent ride it also seemed like RPMs were taking a bit longer to drop back to idle when the throttle's released.
History: Bike is a 2007 with 2000 miles on it. About a month ago it had a relatively minor sidestand fall (bent a clutch lever, no other obvious external damage) - I don't know if this could be related as I've been riding the bike daily and this problem seems to have developed recently, starting with the tricky (throttle needed) starts this week?
Almost definitely not a battery issue, starter keeps going as long as I hold the button.
Weather: I live in Toronto, and it's much warmer now than it was a month ago. Don't know if this could be a factor.
Any ideas what could cause this? Should I clean my carbs? I've never done it before so it might be a bit of a challenge.
How old is the gas in the tank? Did you add any Stabil or anything before storage?
Even if you got a fresh tank of gas, it could mix with older stuff. May take a little bit to work it all out.
Gas is new, put in three days ago. I recieved the bike from the delear with a a full (and I was told fresh) tank of gas on the 25th of March - as I've been riding it daily since she's probably been refilled about 8-10 times since then (I refuel about once every 5-6 days).
Does any of this sound like it could be running rich? I searched this forum a bunch for similar symptoms to mine and I've read that running rich can cause the 'dying when choke is applied' symptom, but I don't know about the slower RPM drop I noticed the other night. Or does it sound like it's more likely to be a jet (pilot/idle?) problem?
Bump... I'd really appreciate some advice about this, it seems to be getting worse and I don't want my bike to die. It's my only means of transportation, I can't get to work without it. Should I clean my carbs? Any advice would help.
Definitely couldn't hurt.
Put the bike up on the centerstand and turn off the petcock. Drain the gas from the float bowls and remove them. Clean the bowls, then re install them. Fill both bowls with sea foam and let them soak as long as possible. Then drain the sea foam, fill with gas etc, etc.
You haven't changed your pilot jets, have you? Might want to bump them up a size and see if that helps too.
I'm assuming that you mean the petcock built into the tank, right, not the one on the side of the bike? 'cause that one doesn't have an 'off' position... not being snarky, I genuinely don't know, I've never done a carb cleaning before.
Most of the videos I found on YouTube about doing a carb cleaning involved removing them completely from the bike. Are you suggesting that, or leaving them on? I don't have Seafoam, but I have a bottle of Suzuki carb cleaner I picked up at a local motorcycle shop earlier in the week since I was getting worried that it might come to this.
I haven't changed the jets, but since I haven't opened the carbs yet I guess I can't be 100% sure whether they're stock. I suppose I probably won't even be sure even once it's opened up, since I don't really have a way to measure them. I bought it used from a dealership and was TOLD that everything was stock, but I suppose they could have been unaware themselves or lied - no reason yet to think they did, though, I guess.
I would like to install Buddha's jet kit and have both replied to the thread about it and PMed him, but no response yet... he seems to have disappeared. Regardless, I guess I'll have to open it up again to install those once I get ahold of the kit since I can't really wait... I needed it working in the meantime since it's my only vehicle. :/
I think I'm going to try to do a cleaning tomorrow using the advice I've been able to find here and on the wiki but the more thoughts I can get on my problem the better. Are there other reasons that using the choke would cause it to die that wouldn't be fixed by a carb cleaning?
Sorry Bomb- I don't own a 500 so I can't help with the petcock. While it is always best to pull the carbs off to clean them, I figured since it was your only wheels you would try the "sea foam dip".
Whatever your problem is, it's around idle. And a lot of folks here said the bike starts easier with a slightly bigger pilot jet. That would be the first thing I try. Head to a dealer or good shop and get one size larger pilot/idle jets.
Yeah - if I can fix this without taking them off entirely, then that would probably be simpler and I'd probably prefer to try that first since there's less risk of not being able to get something back together.
My can of Suzuki carb cleaner seems to suggest that you'd be using it while the bike's actually running - it mentions that RPM will drop while you're spraying the cleaner in the carbs. So far this doesn't really seem to be what I've seen in videos about carb cleanings... would be nice if I could find a video of someone doing this sort of carb cleaning job, even if it's on a different bike...
When you start the bike,the frame petcock should be set on PRI.There is no vacuum going to the petcock to open it up when the engine is off.Prime sends fuel straight to the carbs,but it's a restricted flow.Place the petcock back in the ON position after the engine starts.Your tank petcock has a shut off screw that faces in toward the engine.When it's on,the notch in the screw should be pointing up at the tank.
Quote from: ben2go on May 15, 2011, 08:52:50 AM
When you start the bike,the frame petcock should be set on PRI.
Do you use prime every time you start the bike? Or just while doing the carb work?
I understood that the start up procedure was something like this:
1. Open choke all the way, clutch in, hit starter, bring choke back in if needed so RPMs are around 3000.
2. Wait 20-30 seconds to let it warm up a bit.
3. Bring choke in so that RPMs are around 2000, take off.
4. After a few blocks, bring choke in the rest of the way so bike idles around 1200.
Am I missing a step where you switch to 'PRIME'? If so, at what point in the procedure do you switch back to 'ON'?
Bump... still have no solution to this problem.
So, guys... what would cause choke on it's own to kill the bike? If I give the throttle a twist at the same time as I start it, the RPM will go up and then 'stick' in about the spot it should stay, based on the choke's position, but without the throttle the RPMs just drop and it dies.
So here's what happens when I hit the starter:
Choke only (no throttle): RPMs drop then engine dies after a few seconds. Happens whether bike is warm or cold but dies more quickly when cold.
Throttle only (no choke): If bike is fully cold, engine dies (exactly like you'd expect on a cold GS500 with no choke used). If bike is a bit warmer, it'll stay on at a regular idle speed. So this seems pretty normal.
Choke on, twist of throttle right after hitting starter: RPMs hold at the number they should be at.
Maybe there's a component in the carbs that, if stuck, would cause the choke to not work properly at low RPMs, but twisting the throttle brings the RPMs up enough for it to work right?
Don't have an answer, but I've been having the same problem with cold starts. Without throttle, the engine revs for a few seconds, then dies. To keep it going I have to twist the throttle on full choke, sometimes more than once, then it will stay on. This only happens on cold starts, and it doesn't have to be very cold (I'm in Northern California).
Bomb, it's interesting you mentioned this started after the bike fell on its left side. I started having this problem after a get-off at about 20-25mph. I was turning left on a wet road, the wheel slipped and the bike fell on its left side. Don't know if the crash caused this problem, but since we both dropped it on that side and then starting having this issue, maybe it's more than coincidence. :dunno_black:
I've been meaning to check the carbs on mine, which I haven't done yet. Or maybe a left-side drop can throw the choke a bit out alignment or something??
I have thought that perhaps a needle/slide mechanism of some sort got stuck when it fell, but I'm also open to the possibility that it's just gunk - I bought it used from a dealer recently so I don't really know how it was kept by the PO.
Have you tried anything to solve your issue? What were the results
I took off the air filter and sprayed some Suzuki carb cleaner in the back of the carbs the other day. I'm not 100% sure if it did anything, but I think it may have helped a little - maybe I didn't use enough? It started just a bit easier these past two days, and it was actually colder so it's not just that it's gotten warmer since I applied the cleaner. Maybe I didn't use enough. The instructions said to use the whole can but I'm pretty sure the instructions were meant for a car due to the typical RPMs mentioned. I probably used 1/10th of the can.
I'm going to try Seafoam later this week once my tank's low (too much gas in it now) and see what the results are. If that doesn't help I'm gonna go get a professional mechanic (Rosey Toes in Toronto) to take it apart and clean it and watch 'em do it in the hopes that after seeing I'd be confidant doing it myself if it ever needs more attention.
Crap settles in the carb fuel bowls.When a bike is dropped,it shakes things up in there.It sounds like a fouled passage in the carb or plugged pilot jet.
Bomb, did you try anything other than spraying cleaner at the carbs? Like maybe removing the float bowls?
Each bowl has 4 screws, so it really is easy to do.
Spraying carb cleaner into the carb while it's running actually won't do anything. Think about it: the gas is coming up from the float bowls while air is coming from the air filter. Your dirty carb problems almost always stem from the gunk clogging the jets.
Rich, I haven't gone as far as actually removing the carbs from the bike and disassembling them to clean them. This is my first bike and I'm not entirely sure if I feel comfortable doing that yet. I might take it to a mechanic and have them do it while I watch so I have an idea of how to do it in the future.
Quote from: bombshelter13 on May 18, 2011, 08:50:39 AM
Rich, I haven't gone as far as actually removing the carbs from the bike and disassembling them to clean them. This is my first bike and I'm not entirely sure if I feel comfortable doing that yet. I might take it to a mechanic and have them do it while I watch so I have an idea of how to do it in the future.
Come on, how else are you going to learn? It's my first bike too and I'm a total noob, but I've decided I'm going to clean the carbs and see if this fixes my starting issues. I was planning on doing my first valve check anyway, so I'll just deal with the carbs at the same time, make a day of it. Anyway, I live in California where motorcycle mechanics are a mafia running an extortion racket. Paying them to do basic maintenance just isn't an option for me :D
I'm planning on doing this work by the end of the month, will let you know if it fixes the issue.
Quote from: bombshelter13 on May 18, 2011, 08:50:39 AM
Rich, I haven't gone as far as actually removing the carbs from the bike and disassembling them to clean them. This is my first bike and I'm not entirely sure if I feel comfortable doing that yet. I might take it to a mechanic and have them do it while I watch so I have an idea of how to do it in the future.
There's plenty of walk thrus with pics on here and the home page.It really isn't that big of a deal to clean carbs.
Choke actually sucks fuel through the pilot jets. If those are clogged you will ahve acting up on choke, sadly you also will have it actu up everywhere else under 1/8th throttle. Anyway I'd clean everythign and no do not put seafoam in the tank ... only thing you can do with seafoam is to fill a 3 to 1 mix of it in the carbs. Heck I'd not even bother with that, just open and clean mechanically. Toothbrush, thin wire cleaners for welding nozzles etc work great.
Cool.
Buddha.
Buddha! Just the man I was looking for - okay, so... not in the tank, directly in the carbs. I'll try that out. I'd also really like to buy one of your jet kits, but didn't get a response to my PM. Are you still selling them?