| Author | Message | ||
     Jgamblin87 |
This is my first post although this forum has guided me through the maintenance of my bike for months now. Here's what I've done so far: new battery, spark plug, spark plug wires, LED capable flasher, bu-5000 air filter, BRAND-NEW INTAKE BOOT!, and I've rejetted to 45/175. The bike has a vance and hines exhaust as well. So I have done everything i could think of to rid the cold start/ sputter issue. I have read EZ and Eriko daily to try and figure this out. Having only changed the slow jet on Saturday the bike started first try for the first time ever (cold start anyway.) So two days ago I changed the primary to a 175 in hopes of fixing the stutter. After doing so I killed the battery trying to start it, so I back tracked and checked everything Making certain the carb was seated nicely in the boot. After that I got her started, but not without the typical issues. Note- there was a white vapor coming out like smoke near the carb. Any ideas would be great. It is drive me crazy and I just want her to be dependable. | ||
| Gearheaderiko |
Welcome! Main jet has nothing to do with cold starting, so it sounds as if you may have fouled something up changing the main jet-but its 'okay' now? Changing the slow jet is a big step in the right direction. Did you also drill out the idle mixture screw cap? Depends where the stutter is. At just off idle or riding? Usually shimming the needle fixes the normal midrange or acceleration stutter. Other points to consider: Its not a California bike? Is the timing correct? Has it always done this? Spark plug gapped correctly? What gas are you running? There's a vacuum port on the carb which has a cap that cracks and causes a leak. Check this.However,not all Blast carbs may have this port. It should be on the top of the carb just before the boot. It may just have a solid fitting without a hole or no fitting at all. There are other causes but these come to mind as the most common. So check these first. White vapor is probably just unburned fuel mix vapor and very likely 'normal' and not a direct indication of something wrong. Keep us posted. | ||
| Jgamblin87 |
Thanks! I have been reading EZ and your posts since I got the bike, and you two are charitable beasts ha ha! I know that the primary has nothing to do with the starting but it definitely made a difference while riding (as long as it starts...)! The idle mixture screw had been drilled and was about 4 turns out, so I screwed it in then backed it out 2 1/2. The stutter is while riding it tries to cut out, and this happened before and after my work on it. I have only had the bike since august, but yes it has always done it. It is not a California bike though, and this is embarrassing but i'm determined to keep this a D.I.Y project. I have no experience I have literally learned everything from you and Ez. With this being said I don't know much about the timing or how to check it. I did gap the spark plug, and I have only put premium in the bike since I bought it. I will have to do some reading and try to check the vacuum port out. It is odd that right after I changed the slow-jet she started and Idled like a monster, and she hadn't been started in three weeks... First try! I love this bike and I'm determined to whip-it into shape. Since they aren't made anymore i'll probably keep it forever. Thanks for getting back to me! | ||
| Jgamblin87 |
Hey Eriko, Maybe the carb just needs a "good cleaning." I'm totally kidding. I just can't count how many times I've read you telling someone not to do that! | ||
| Jgamblin87 |
I'm going to attempt to set the ignition timing, and am wondering if it is imperative that the back wheel be off of the ground? or if that is just for ease of moving? I understand the process after reading, but will it be obvious if there was an issue? (barring an erratic light on the module). So I essentially just want the LED to light up when the TDC is in the middle of view? | ||
| Swampy |
You want the wheel up so you can turn the engine over. Take the spark plug out. Use 5th gear. To static time the Blast you need to think End of Event timing, in other words the LED is shutting off at TDC. Once you have the static timing set then you should set the dynamic (running) timing, but I have found it always to be "right on" after static timing Best of luck to you. | ||
| Johneblast |
To add what Swampy said, you'll want to listen for the exhaust stroke to hiss out before you line up the TDC. Right after it hisses, set it at TDC, then rotate the module plate until the led just goes out. I like to rock it back and forth to make sure I hit the "sweet spot" when the led goes out. Rotating the tire you'll find it a little tricky to catch the TDC as the cam lobe will "grab" the rotation and then release it rather quickly, so get a firm grip on the wheel so it won't want to rotate past the TDC mark. | ||
| Jgamblin87 |
Alright I got it timed and also adjusted the idle screw a bit. The bike is responding a little bit better, so I'm going to let it cool down and then see if it'll start easy. Thanks for all the "know how." | ||
| Jgamblin87 |
Well it cooled down and still gave me some trouble starting. It idles and runs much better, but now I'm wondering if it is auto-enricher. It wants to start it just has trouble getting there. Does the vacuum port that Erik spoke of just look like a black knob? | ||
| Gearheaderiko |
About the size of a Q-tip end. Its just rubber/plastic cap. Should come off easily (if it has one), but being a 2003, it will probably split from age on removal. It should be on top of the carb just before "Das Boot'. It is normal that the bike starts and runs much better after changing to the 'bigger' slow jet. Dont jump to conclusions about the AE just yet. It should start pretty easy with the 45 slow jet. When you're trying to start the bike watch the LED on the ignition module (Its okay to leave the cover off and run the bike). The LED should flash at regular constant intervals. The flashing LED means there should be a spark with every flash. Check that. Sometimes, when the battery gets run down (or old), the starter and headlight will steal the power away from the ignition. That will give you the whole "sounds like it wants to start" scenario. Anyway its an easy test. I'd leave the ignition/timing cover off until you're finished fixing the current problems. A quick and dirty test of the AE is to unplug it and see what happens. That will leave the 'choke' in full on position which means it should start easy, but will eventually start spewing black smoke or idle very rich and struggle to stay running. But see what happens when its cold again before you proceed with unplugging. FWIW: Blasts are notorious for hard starting when not quite cold and not quite warm. | ||
| Gearheaderiko |
This is the carb as it sits on the bike. On the left side of the picture is the intake boot where it enters the engine. Above the #10 is where the vacuum port is (as shown in the picture-but not numbered). http://www.badweatherbikers.com/buell/messages/201 64/296709.jpg (Message edited by Gearheaderiko on December 24, 2011) | ||
| Jgamblin87 |
Erik, Thanks for the response. The ignition module LED blinks in a steady fast rhythm. Also, the battery was bought in September unless it is just faulty. I'm going to give it a good thorough charge as I've killed it a few times trying to start it. Thanks for the advice on the AE i'll give it a shot. As far as the vacuum port do I just visually inspect it? Thanks so much for your time. | ||
| Gearheaderiko |
Pull the cap off and see if its split. They usually fall apart with age. I just wasnt sure if you knew what and where it was, so I didnt want you to take a pair of pliers to something that wasnt the vacuum port cap!!! | ||
| Jetlee |
The biggest change that eliminated my carb-cough was adjusting my idle mix and timing, which looks like you've done with success. I had a similar cold-start issue as well; however mine was self-induced. My choke was disabled. As soon as I fixed my choke, cold-starts are super easy. Maybe check your choke to make sure it's not stuck "off", pushed out and blocking fuel. -Edit- Not trying to counter Erik, I go to him for help. Just expressing my experience. He's got more, though.  (Message edited by Jetlee on January 06, 2012) | ||
| Jgamblin87 |
How do I check the choke? Sorry for a seemingly dumb question, but I am new to this all together. Also, it was running fine but it started "sputtering out" on me in second gear, and when I would give it throttle it would stutter really badly lurching forward. I am wondering if this could be due to dirty fuel lines. After adjusting the ignition module and the idle screw I can get it to start quicker, but I typically have to pump the throttle fully a couple times to do so. Thanks for the help | ||
| Jgamblin87 |
I forgot to add this: when I got the bike it was set on reserve fuel, and for good reason I guess because t runs better that way although not like it should still. | ||
| Gearheaderiko |
Its likely not the choke. Besides making sure the carb boot/intake boot/Das Boot is still good, two causes come to mind,. But since it seems to run better on reserve I'd see how it runs with the gas cap loose (BE careful). That would cure a fuel tank vent issue. The second cause may be ignition module related since it seemed to get worse under load. That might be caused by a bad ignition module or a faulty safety switch. Bypass the kickstand switch (jump the 2 wires together) and then flip the clutch diode and most safety switches will be bypassed. However those arent the only things that could cause your problem. Dirty fuel lines,? Maybe. A clear plastic (for an old air cooled VW) inline fuel filter works well, but dirt will usually just clog up the slow jet usually putting an end to any real running. Drop the float bowl and you'll see dirt. Check the slow jet, is it clear of dirt? If neither show signs of dirt, you dont have a problem. The clear fuel filter will also allow you to see if you have fuel and if its dirty. Pumping the throttle shouldnt have any real effect as the Blast carb doesnt have an accelorator pump so that wont give it any extra gas. 'Feathering' (which is close to pumping, but less effort) might make a difference. Please reread all previous posts, especially the one where I asked all the questions. We cant see or hear the bike and we can only go by whatever information you give us. We dont have any knowledge of its history of repairs or problems. With quite a few problems the answer may be obvious (Das Boot is usually the answer), after that we need as much information as possible and need to know what paths have been taken to correct this or previous problems. Have you checked the consistency of the LED light? Did you find the vacuum plug on the carb? | ||
| Crackhead |
Do you have a timing light that you can use to pull timing off of the spark plug wire? I was able to diagnose the ignition module going out by just reading the rpms / spark events. When cold the rpms / spark would be constant but when hot it ignition module was not consistently firing, and would randomly skip a spark. I could watch the rpm read out, the bike would fluctuate +-20 rpms and then drop to 0 for a split second (just like I unplugged the timing light leads). and then go right back to the normal RPMS. The testing was all done in "N" with the bike up on a rear stand and all safetys by passed. | ||
| Jetlee |
You should not have to touch the throttle at all to start the bike...ever. | ||
| Gearheaderiko |
true. | ||
| Jetlee |
Along with everything Erik's mentioned; Check ground connections. Remove, clean, sand/grind/file/etc, clean again, then replace and tighten. If you're using a thread-locker, be careful to not get it between the connector and the frame. | ||
| Ezblast |
Damn their good! |
