| Author | Message | ||
     Joplin |
I posted this in the KV section and didnt get much response,, " Hey all, I gotta run this buy you all. I have a 95 S2 that is running like crap, if you can even call it running. Story goes like this, I had it in the shop (never again) to press in a fifth gear bearing. Long, tortured story of idiot work, and I nhad done all the disassembly so all they were doing was the bearing and secondary drive sprocket, but when they delivered it back to me, the bike was on its side in the trailer. Like I said, idiots. Anyhow, every since then, it has a vicious backfire sometimes even when i crack the throttle. I've ckecked the VOES and the carb gaskets/seals, and exhaust studs. Is there any way I jacked up the timing when I removed the tranny? Plus, would a cracked header cause this? Thanks for any input , jm " and I thought I'd post here as well. My backfire seems to be most pronounced when I crack the throttle. I do have a slight miss when idleing. This is a stock S2 as far as I know. I live in Denver so the air is a little thin. But, the deal is, it ran fine until above mentioned events. I did have a little problem with some gas from the overflow, but that resolved itself. I really appreciate any input as I am getting pretty frustrated not riding. Also, this forum is my service shop, the ones around here suck,,,plus I am a poor s.o.b. and dont have the $$. thanks for your help,,, jm | ||
| Road_thing |
Serious question: Which side did it fall on? If it was on the left, you could have a cracked sparked plug or a loose plug wire. But, since you're checking the carb and asking about cracked headers, I assume it fell on the right side. If that's the case, I'd look real hard at the mounting bracket for the carb, make sure it's not bent so that the carb can't seat tightly on the manifold. Check for intake leaks with WD40. I'd be surprised if an exhaust leak caused it to backfire and run rough, but I've been wrong before... rt | ||
| Cataract2 |
Also, go back to the shop and kick their collective rears for the treatment of that S2. | ||
| Joplin |
RT, thanks,, I dont think it fell hard on the carb or headers, it was still tied, after a fashion, an dthe breatyher looked fine. I have checked the seals, even tho i replaced them like 10 miles ago, with carb cleaner sprayed while running and didnt change the idle. The reason I mentioned the exhaust studs is after a search of the boards, there was some talk of backfires from loose exhaust stud nuts. But, there is a stress crack in my header ( anyone got a cheap stock header, looks not important???) and i wondered if the leak of backpressure might be similar to the loose exhaust nut symptom. Thanks for your input, JM | ||
| Henrik |
If you've had gas coming through the overflow, could you have some crud in the float valve?? Henrik | ||
| Road_thing |
"stress crack in my header" Jeez, THAT's a first...  I got news for you, Janis, stress cracks in the tubers' headers are about as rare as bug guts on the headlights! There's tons of info in the knowledge vault on repairing and preventing header cracks. I doubt that's what's causing your backfiring, though, in my experience, header leaks, whether caused by cracks or leaky gaskets, are more likely to cause backfiring on deceleration than at idle. Timing could be the culprit, but if all you did was remove the trans from the primary side, I don't see how you could have moved it. If you pulled the cam cover for some reason, though, it could have moved. I think you're right to suspect a fuel issue. Henrik (as usual) is looking in the right direction. Backfiring at low rpm when the throttle is opened sounds like a lean condition to me. Maybe the accelerator pump? Float level? Clogged pilot jet? Check the KV for jetting recommendations... Let us know how it turns out! rt | ||
| Buelliedan |
All the above sound like good suggestions but don't overlook the sim ple stuff either. First thing I would do is put a new set of spark plugs in before spending money on anything else. I can't tell you how many times one of my bikes just needed a simple plug change to make it run better. As for the header. I have a stock header available thats in perfect condition but its not cheap. I would need to get $125 for me to part with it. | ||
| Road_thing |
New plugs--right on, Dan. I'm also stockpiling headers... rt | ||
| Joplin |
Hey guys,,, wanted to say thanks for the input. I followd your hints and looked back to the carb and found that when I put it back together after the overflow problems I didnt get the accelerator rod back in its hole. No wonder it was running lean as henrik and rt pointed out. Thanks for the time,, running fine now,,whew,,with the weather in the 70's I needed this thing to run,,,lol. jm |
