| Author | Message | ||
     Dannybuell |
My 96S1 with 99,000 miles has intake fresh seals, a new Mikuni (6 months) and an older crane ignition. On two different rides, I'm just cruising along and BANG! the bike backfires out the pipe as loud as a hunting rifle. I checked the leads to the coil nice and tight. On the second ride I backed off the accelerator pump which did nothing to slow the backfiring. Has this happened to anyone here? | ||
| Harleyms |
fuel vapor building up in the muffler and then igniting? where's the bang coming from? | ||
| Harleyelf |
You have an intermittent failure to spark. Take the easy steps first; new plugs, tight ends on the plug wires or new plug wires, check coil wiring under tank for worn insulation.... then it's your coil or cam position sensor or module. | ||
| Reepicheep |
You might be able to see the bad CPS on the tach... if it increases RPM when you are loosing speed but still in gear, you know the CPS is lying. Or if it drops to zero while you are still in gear and moving, you know it's lying. A simple oscilloscope makes it easy to spot problems that are otherwise very difficult to track down. | ||
| Dannybuell |
thx i'll check electricals first. | ||
| Dannybuell |
I checked all of the wires, the fuel filter, and inspected the nose cone, couldn't find anything. I took it out onto the freeway gave it a blast or two and no problems. IDK what it was but it's gone now. Thanks for all of your input. :-) | ||
| Paint_shaker |
Don't forget to check the kickstand kill switch (at the clutch lever). | ||
| Dannybuell |
THX | ||
| Dannybuell |
I got caught in a little Oregon sunshine last night. On the freeway it backfired but not as hard, I may be getting used to it. When I looked down at the guages I noticed the tach needle was bouncing high and low at steady throttle. Any new ideas? | ||
| Kc_zombie |
Hmmmm..Possible vacuum leak at the VOES, failing VOES switch or possible intake manifold leak or combination of the three? Heck even an exhaust leak at the head/pipe connection can result in a back fire when decelerating.. I would start at the VOES... Good Luck | ||
| Creature_x1 |
I know of a historic issue with crane hi-4 ignitions. If all else fails, look into that as well. | ||
| Natexlh1000 |
Unstable tach means something in the ignition is being odd. Perhaps it's not always odd enough to cause an actual misfire. | ||
| Brumbear |
bad coil or wire |
