| Author | Message | ||
     Rwcfrank |
With all of the conjecture of fans running and air cooled engines. Has anyone ACTUALLY had a failure due to overheating? I have not seen or read about any. | ||
| Ft_bstrd |
I think Vern had his bike go into skip spark when his fan failed coming home from Homecoming. I've had my bike ping a bit when stuck in stop and go traffic for an hour. | ||
| Rwcfrank |
Excuse my ignorance but what is skip spark? | ||
| Johnny_uly |
I believe that is where the engine only fires every other time so it does not generate as much heat. | ||
| Ft_bstrd |
Exactly right. It's the last line of defense of the ECM to prevent permanent damage to the engine. Every other cycle has no spark. In overheating situations, it allows cool air and cool fuel mist to enter the combustion area and cool down the engine. Mine went into skip spark mode during the stator/voltage regulator failure. The charging system wasn't producing enough power to provide sparks every cycle above a certain RPM. | ||
| Rwcfrank |
Thats what I love about Badweb, you learn something new every time. Thanks Ft bstrd, I guess when you start to feel the skip spark its time to let her set or get some fast moving air to the engine.. | ||
| Etennuly |
Actually mine went into the run skip mode in traffic in Knoxville last summer on a 90F day. Sitting still in traffic the fan just failed to come on. It got so hot to sit on the bike if the light hadn't turned green when it did I was heading for the sidewalk just to get off. As I got it moving it cooled back down and the fan started and worked normally for another couple of thousand miles until quit it in a puff of smoke 600 miles from home. I made it home from that trip with out hitting the run skip mode by shutting down early in traffic stops and when I pulled off. If your bike ever gets to the run skip mode you will be well informed by the amount of heat you personally will have to endure. You will not want to be on that seat! I have run my bike over 5000 miles since with no ill effects from the situation. It still uses no oil between changes and does not smoke, tick, knock, or rattle any more or differently than it ever has. Oh, and I run HD dino oil with weights based on the temperature by the book. | ||
| Curly |
fortunately, i have not had to experience this yet, but traffic back-ups seem to find me. my question is what is the best thing to do when the engine goes to spark skip? should you shut it down immediately or hit the shoulder and risk a ticket from officer friendly? i guess my question is how long can you run in spark skip mode without doing permanent damage to the engine? | ||
| Ft_bstrd |
The purpose of skip spark mode is to cool the engine and prevent damage. Pulling over will allow the engine to cool, but not as quickly as keeping it running. The engine is air/oil cooled. Cool air must be moving past the engine to cool it. Skip spark allows intake air and fuel to mix but not combust every other cycle. This allows the piston crown and combustion chamber to run cooler. The evaporation cools the inside of the engine. There is also oil cooling. The oil runs through the cooler and then is sprayed onto the bottom of the piston. Ultimately, shutting down only allows the cooling fan to cool the engine. That is infinitely less efficient than running the engine at at speed where you have cool air over the fins, cooler oil circulating, the cooling fan running, and skip spark mode. | ||
| Atoms |
Sounds to me like we need to legalize lane-splitting everywhere where it is not already legal. It does not seem so far-fetched really, to attach a provision to the next Transportation bill(?) in same manner that the .08 BAC limit got imposed on all the states. | ||
| Curly |
hey, thanks for that great info for us newbs. i would have assumed cutting the engine would have been the thing to do. now i know better. | ||
| 2evil4u |
Had a severe case of skip-spark on my Uly last Friday. We iron-butted from Baton Rouge to Las Cruces on our way to Las Vegas. (I replaced the fan three days before we left.) After San Antonio, when the speed limit goes to 80, the bike would only hold between 67-72 without skipping. It was 105 air temp and in addition to my 205lbs I had the bike loaded with about 200lbs of gear including the aux tank of fuel. After 8 hours or so the air temps had cooled enough to run back up to 75. The next day, with temps in the 40s-70 there were no issues. No issues for the last 5 day's thrashing about in the mountains either. Heading home tomorrow. We'll see how she fares. |
