| Author | Message | ||
     Unix |
Hi, recently a problem popped up with my Buell... it has problems starting, i have to roll the gas a few times before i crank it for it to even get any reaction... and when it starts it rumbles for a few seconds and abruptly dies. After the second or third time i can get it running, but when it's idling on choke the engine seems to misfire, it also backfires through the exhaust. When it warms up and i try taking the choke off, the engine isn't able to idle... it dies all the time, i believe it could even be running on 1 cylinder! When i roll the gas i can keep it alive and start riding, and after about 15-20 minutes the engine idles ok and doesn't die, however from time to time it backfires. The problem seems to be getting worse. I checked the cables on the plugs, they sit firmly. The plug cables are new, ACCEL 8.8mm. Spark plugs were changed recently, along with filters and oil. I suspect it could have something to do with charging, maybe the voltage regulator ? any ideas? | ||
| Djkaplan |
Triple check anything you did first... but it sounds like something is blocking either the pilot or mainjet in the carburetor. | ||
| Shooboy |
Yep, I agree, time to clean the carb. Definitely sounds like you got something in the pilot jet. The reason it fires when you twist the throttle several times is it gets extra gas from the accelerator pump and it fires on that squirt of fuel. The other possibility is a piece of crap in the enrichner circuit, which says choke on the pull knob, but it really isn't a choke. It's an enrichner for cold starting, and it's fed through the pilot jet circuit. Pull your air cleaner and your carb support bracket, pull carb off rubber grommet that holds it onto manifold, remove 4 bowl screw and remove your main jet and your pilot get and make sure all is clean and all holes are clear. You shouldn't have to remove the throttle cables or fuel line, I didn't have to and I just changed my jets. Good luck, keep us posted, Shooboy | ||
| Nevrenuf |
i don't know if this would help but check the needle valve to make sure it din't pop out and get stuck. | ||
| Djkaplan |
You can drain the carb before you check it by turning the petcock off and loosening the brass colored drain screw with a 14" flathead screw driver. You have to do it from the left side of the bike... you'll see exactly what I'm talking about if you take a look. Slip a 3/8" or larger hose over the drain tubing on the bottom of the carb and let the gas flow anywhere you want, preferably not on the floor of your garage. | ||
| Unix |
ok, so i think i found the problem with the engine backfiring and not being able to idle properly. The intake manifold to the rear cylinder seems to be leaking badly at the intake/head joint. Before starting the bike i rolled the throttle a few times, and noticed gas dripping from that area! So since gas is leaking i bet it must be getting a lot of bad air, which causes the idle problems and backfiring. Oh, when i start the bike and it keeps dying on idle, i checked the headers, and the front is warm while the rear cylinder is cold - so i'm pretty sure i found the gremlin  That just confirms my theory that 99% of the problems that will occur with the bike will be caused by the huge vibrations the engine produces at idle - which cause parts to fail. thx for all the input (Message edited by unix on July 23, 2008) | ||
| Unix |
well tomorrow i'm gonna take the intake manifold off - along with the carb. I'll be changing the intake seals, but the carb-to-manifold gasket will be reused (as long as it won't fall apart on removal). Any advice on this enormous task (for me at least - hehe - the consequence of owning a jap bike before) will be greatly appreciated. | ||
| Cyclonecharlie |
A very LIGHT coat of Vaseline on the seals(all three)makes assembly much easier and less chance of damaging new seals. |
