| Author | Message | ||
     Mpenalver |
Hey guys, Yesterday I got my new to me blast up and running. I was so excited that I took off for a ride with out tightening the oil filler cap. Oil went everywhere. Now the bike will fire when it's cold, will run for a minute, but then it shuts off. Any advice? I don't know how badly I farked things up, but I was wondering if there are any awesome diagnosticians or theorists that might give me suggestions on places to start. I assume that with low oil, the hydraulic lifters won't pump up so the valves won't open all the way. So I tried adding oil. There's no difference. Any thoughts? Any easy checks I can perform? I'll do a compression test tonight Marc | ||
| Mpenalver |
Uh problem solved. There was a lean condition after the choke reopened. Turns out the boot wasn't on just right. Diagnosis took 3 minutes and 20 cents worth of ether sprayed in the vicinity of the boot with the airbox on and sealed. This morning in the daylight I saw that the boot was slightly out of position. It took me 20 min after getting the boot on properly to realign the carb with the airbox. That is not exactly what I consider a precise fit. As for the oil that went everywhere, it amounted to less than half a quart. Now the bike only has a slight backfire issue while it's warming up. This seems par for the course, so I'll live with it until I can't. | ||
| Ezblast |
Replace boot. Then if you still have popping, then drill out the sauder plug of the air screw, and set air-screw 2 1/2 turns out from light bottom. Problem solved. EZ | ||
| Mpenalver |
EZ, I've changed the boot and the air filter, as well as the engine oil and oil filter. I've got a new problem now. FYI it's a 2003 with 88XX miles and no service record. After coming to a stop at a traffic light, the motor won't produce enough torque to get me moving. The idle drops, no matter how much throttle I give it. After 20 seconds of almost no throttle, the engine revs up and usually produces enough torque to pull away. Sometimes it doesn't and I have to repeat the process while traffic waits impatiently or goes around. It's kind of like an extreme flatspot in the throttle. I feel like I've already got the idle up higher than it should be. My only other motorcycle is a XL600 which is also a thumper but has gobs of torque at the low-end. Will adjusting the airscrew as you recommend solve my problem? Would increasing the idle jet or shimming the needle be appropriate? For what it's worth, the problem does not occur if I come to a stop at a stop sign and I don't have to wait for any cars. (Yes I come to a complete stop at every stop sign, even if my feet don't touch the ground) | ||
| Ezblast |
Your still having an intake leak - check boot and clamps, when you first start the bike and up till ten minutes later, you should have a high idle 1800 to 2300 rpms, after riding around for 1/2 hour, idle should be between 1000 to 1200 rpms - that is the idle you set and then you would correct for any other problems. When you are sure that your intake is good, then warm up bike with 1/2 of riding, then adjust idle at idle. EZ | ||
| Mpenalver |
Thanks Ez I'll check the intake again. I did spray some ether on and around the boot this morning and I didn't get any revving so I figured it must me something else. That said, the problem manifested itself later in the ride so I'll check again before I leave for home. | ||
| Mpenalver |
Well, the bike only runs on ether. So it's definitely lean, but the Carb boot looks ok. I bought two so I'll try another one tomorrow. I checked the idle mixture screw and found that it had already been uncapped so I set it to 2.5 turns out from resting. I've ordered a 45 idle jet maybe that will enrich the mixture enough. Has anyone experienced leaks at the airbox? I think the junction of airbox to Carb maybe the source of the leak or possibly the airbox cover. | ||
| Ezblast |
Check diaphragm seating and for tears or pinholes in it. First make sure carb vent line is properly plugged, boot properly seated, and use a new intake gasket, I never had luck reusing mine, others have. For a stock exhaust set at 2 turns, and then if any popcorn, go a quarter turn. or go 2 1/4 from the go - probably a better idea, seeing as you would have to take off the airbox, and then new gasket, etc. - and one last thing - 45 is still plenty lean - in the af's I have seen - with 14 as the bottom - whew - must be a good design in that motor somewhere to be so cool running while running so lean. EZ | ||
| Kauai1800 |
Wanted to chime in here that even after changing the boot and messing about with it as you have, that twice now the issue has been that the boot was still not on correctly. Although I know it makes no sense, I too have tried the ether trick and seen no change, but then simply unclamping and readjusting the boot got things cherry again. I'm a scientist by training, so stuff like that drives me nuts; but nevertheless it's the way it is sometimes. If you had a torque screwdriver and could tighten the boot clamps precisely to spec instead of just 'real tight'- I suspect that might be what's behind the problems we've all had or seen. | ||
| Mpenalver |
I sorted out the non-running issue and wrote a haiku about it. Water in the gas There was no way I could have Started the motor I wasn't able to properly adjust the idle, nor did I install the 45 idle jet. I'm still running the 42 jet. There's still some(much less) backfiring from the exhaust and some from the carb. Is this likely to be cured by opening the mix screw and or installing the new idle jet? How do people measure the rpm to set the idle without a tachometer installed? If I install a new idle jet should I install the 175 main as well? At the moment I'm running a stock intake and exhaust although I'm considering adding a Dan's Custom intake and a vance+hines exhaust shortly as well as a 515 kit later if I love the bike, but decide I want more power | ||
| Ezblast |
for now 45/170 would be good, just consider jetting a part of changes - lol - screw setting for stock is 2 turns out from bottom. A Trail Tech. Tach works, cheap also. Good haku - very in the moment - lol EZ |
