| Author | Message | ||
     Wiredawg119 |
Here's my story: It started one day when I brought the bike down to a friend’s shop. He has a motorcycle dyno, was bored, and wanted to play around with it. All the bike had was a Kerker exhaust the previous owner had put on. I've only had the bike for about 2 weeks at this point. When I made it to his shop, a friend of mine took it for a ride but it died up the street. Turns out that intake boot had ripped. They made me one out of silicone hose and all was well. When I got the bike back, it ran great! He cut the Kerker can off and ran a straightpipe from the headpipe. He also shimmed the needle 2 washers and drilled the main jet a little larger. I’m still using the stock airbox. Weeks later... I was riding home from work when I noticed a popping coming from the carb into the intake box. I rode it home like this and checked it out when I got there. The silicone intake boot I had came loose. I tightened it up and thought all was well. It sat for 3 or 4 days after that. I went to start it to go to work one day when the problems started... The engine would start and idle but whenever it came off of auto enrichenment it would slow down make banging noises and die. I tried to play with the idle mixture screw with no luck. After much searching here, I decided to go with a larger slow jet (48) and just go ahead and buy a new OEM boot as I did not like the fitment of the makeshift one I had. Still the same problem. My timing is fine, I checked that. If I rotate the module all the way clockwise, it will run better, but I don't want to do that in fear of messing something up. So I keep it where it should be. If I unplug the TPS and enrichener it will idle fine but run like crap. I thought it to be lean, but with a jet that size and 2.5 turns on the idle screw that shouldn't be. It won’t die if I hold on throttle but it reeks of gas and when I rev it higher, it backfires flames. PLEASE HELP ME!!! I have no idea what to do next. After reading here, people with similar problems fix it with a new intake boot. I have a new one but have the same problems still  I called Buell for advice, but of course they need to see it and charge me hundreds of dollars…. | ||
| Swampy |
Check your main jet, drilling them out is not an acceptable way of increasing the size. Just go get another. Check your fuel tank vent. Check to make sure you are not having a fuel delivery problem. | ||
| Wiredawg119 |
The jet was drilled with a set specifically made for that application. I questioned this at first but my friend said it was common practice. Plus it ran fine for weeks. I don't see how it could be that. I did take it out anyway and it visually looked good and was not clogged. I know the fuel tank vent and everything to the carb is good because I drained the tank by disconnecting the hose from the carb and draining into a gas can. Everything came out ok. Could I possibly have a bad TP sensor? | ||
| Ezblast |
No a bad leaking boot - replace with OEM. EZ | ||
| Wiredawg119 |
There is a OEM on there. I replaced the silicone one I had. Still the same though I'm going to pull the carb apart to look around again. I do appreciate the suggestions though. | ||
| Reuel |
TPS isn't likely to do all that. Connect an ohm meter between two pins on the TPS connector. Turn the throttle slowly from zero to WOT. The resistance should change smoothly without any jumps. | ||
| Ezblast |
Ignition - test - probably needs replacing. I re-read your post - ruled out the safety switches - kickstand and clutch - you disabled both of those already to test? If it is still doing it after disabling the safety stuff - its probably either carb or ignition - considering how long everything was fine - suspect ignition, but I would check the safety stuff first. EZ | ||
| Gearheaderiko |
A lot of good suggestions. My thoughts (but no solution): Make sure the timing is correct per the static method (LED) and the dynamic (timing light). Disconnecting the TPS wont do anything bad. You may lose some throttle response and mpg, but thats about it. You may want to check the timing with the TPS disconnected. Usually if you disconnect the TPS you've also disconnected the 'choke' (auto enrichener). If you smell rich, you may have fouled the carb by possibly messing the float adjustment, dirt in the needle seat or elswhere.Dont change jetting because it started to run bad. If it ran fine before, then the jetting was fine (FWIW: a 48 slow jet is "Big Twin" jetting-very rich-yes I know its currently the "hot" ticket, but still very rich).What is or was it jetted at? Dont make modifications or deviations from the original settings (when it was running good) until you get it running good again. Then modify. Plenty of people have installed the intake boot incorrectly. It does sound like a bad ignition module if it reeks of gas and backfires flames. That indicates erratic or incorrect timing which is very common with a bad module or incorrect timing. Check or change the spark plug. Some plugs go bad quick with fouling (Champions come to mind...) and you can pull your hair out getting them to run well again. Again, avoid the 'change everything or disassemble everything approach to repair'. It'll only make things worse. Stay the course of trace the problem and diagnose. | ||
| Reuel |
Disconnecting TPS and the Autoenrich will result in a longer time of fast idle. The autoenrich actuator will have to be actuated by engine heat. Not a biggie for diagnostics. Erik is dead on! It worked for a while. Check for things that have come loose. I've learned the hard way about checking things after a week or two... | ||
| Ezblast |
Also following Erik's logic - loose timing cup. EZ | ||
| Gearheaderiko |
That will drive you really crazy!  | ||
| Wiredawg119 |
I ended up taking the carb all the way apart. Everything looked good, but I gave it a good cleaning anyway. There was some gunk though. I think it could have been from the octane booster I used on it. I stopped at a gas station that only had regular and filled up (only station in the area and I was empty!). I usually use premium. It ran a tad crappy so I dropped some octane booster in. That's about when it all started.... Seems to run ok now. Not perfect, but ok. It's not sounding like it did before. I will now play around with the idle screw and hopefully get it right. Reeks of gas in my garage, it's a lil on the rich side. Thank you all for your advice! |
