| Author | Message | ||
     Cactusjack578 |
I have a stock FI 99 Thunderbolt with 29,000 miles. It has a fat spark and is getting plenty of gas but it won't start. I took off the air filter and found quite a bit of oil inside. The carb? throat was black from oil. Anyone have any suggestions where I should start? | ||
| Buellzebub |
side stand safety switch, neutral safety switch, engine kill switch... | ||
| Sparky |
I take it, it cranks but won't fire? If so, try spraying some "Easy Start-Up" spray from Pep Boys, Auto Zone, etc. into the open throttle body. If it fires and stays running, you're home free. If it fires but dies, then it's not getting fuel. Spray & try it again. If still no go, troubleshoot the fuel system. Could be anything from contaminated fuel, clogged injectors or fuel filter, faulty fuel pump, broken wire to fuel pump, any number of things? If it doesn't fire, it's not getting spark or the spray. Spray & try it again making sure the spray is going inside the manifold. | ||
| Henrik |
Did you work on the bike recently? Change any parts? If you still have the crank case breather routed into the intake, that would explain the black in the intake. Henrik | ||
| Dave |
Sidestand safety switch is my bet as well.... DAve | ||
| Elmono |
Cactusjack, I'm no pro here, but I have experienced the same things you've described so here's what I did. The oil is normal, as this is how the heads breathe. But if excessive, use less oil. I've found that the 2 quarts recommended by the manual makes for too much oil in my air filter. Also, there's a lot of info on here about catch cans and oil filters. As for the no start, I recently replaced my speedo sensor and when doing so I accidentally unconnected a wire to my starter. Also, the electrical connections on my bike are very sensitive. I use alot of WD40 and electrical grease to keep things clean and connected, thus allowing for uninterrupted electrical service. The wiring diagram in my manual helps me follow the wire trail to the culprit. Hope it helped, Chad. | ||
| Cactusjack578 |
Thanks for the input guys but if my problem was a side stand neutral or kill switch the engine wouldn't turn over. And like I said it's getting plenty of gas. I even tried spraying Easy Start and just barely got a sputter. The bike was getting harder and harder to start before it finally gave up. I'll try replacing the fuel but I'm not counting on that working. Keep the suggestions coming. Thanks | ||
| Mick |
whats the compression like? | ||
| Dave |
The bike will turn over with a bad side stand switch. This keeps the rider from pulling off with the side stand down. Crank...but no start will be the symptom. Jumper the 2 leads going to it just to make sure. DAve | ||
| Cactusjack578 |
Thanks Dave, but if the engine will turn over on a bad side stand switch then it must stop the spark to kill the engine right? What do you mean by jumper? I'll try anything at this point. I had the plugs out but didn't pay close attention to the compression I'll take a look at that again thanks Mick. | ||
| Blake |
Sidestand switch is not in play if the clutch is pulled in or if the bike is in neutral. If the engine is indeed sparking and getting fuel, then the issue must be combustion chamber related, as in serious valvetrain or holed piston related issues. Compression and leakdown testing is in order. | ||
| Bomber |
timing can slip, tho it's not usual -- I'd check that first (esaier to set timing than replacing pistons and valve) | ||
| Ceejay |
timing??? have you pulled the timing cover. These things shake a lot, pins holding down the cam sensor could be backing out, allowing the cam sensor to move forward or backwards, even the smallest amount is a couple of degrees retard or advance.... | ||
| Whodom |
If you could give a little more background, it would help a lot in troubleshooting. Did the bike just die and then refuse to restart? Was it running fine one day and then wouldn't crank the next? Was the bike running OK, you worked on it, and now it won't crank? | ||
| Sparky |
Perhaps a few more details would help. When you said it has a fat spark, is that at the spark plug electrodes or from the spark plug cable to the plug terminal? Is the ignition stock? What was the condition of the spark plugs, oily, fouled or clean? How do you know it's getting plenty of gas, can you smell it out the exhaust or is it dripping from the throttle body? If it sputtered with the easy start spray, but doesn't run on its own, contaminated fuel is likely. Could be water in the gas. How old is the gas? Does it smell fresh or bad like turpentine? | ||
| Phat_j |
whats the compression like? hit the nail on the head.... from the original post, it has spark and fuel an internal combustion engine needs 4 things to run.... air, fuel, spark, and you got it....... compression. my bet........ hung open valve. | ||
| Ceejay |
bombs-apparently great minds think alike...If you holed a piston, I'd think it wouldn't get worse, same with a dropped valve... | ||
| Cactusjack578 |
My S3T is bone stock. It was running fine then began to be hard to start. Then one day it started sputtering off and on while riding like it might be misfiring. When it would first start up it would run on one cylinder for a few seconds before the other cylinder kicked in. When it would finally start it would blow dark smoke like it was flooded. I figured that was from running on one cylinder when it was trying to start. I quit riding it because I couldn't figure out the problem. Now it won't start at all. I know it's getting gas because the spark plugs are wet. I know it's getting spark because the spark plugs are sparking big fat blue sparks. I haven't been working on the bike other than replacing the battery and the battery has been on the bike since before she quit running. I have a Sportster too and I have yet to see oil in the air cleaner like I've seen in this Buell. I appreciate everyones help on this. It's been very discouraging. Thanks, Cactus Jack | ||
| Cactusjack578 |
Ceejay, I like your timing idea. I'm going to change the gas, install new spark plugs, try to re-route the breather tubes, and check the timing. Oh yeah, I'll check the compression too. Anyone else got any ideas? Thanks all of you, Cactus Jack | ||
| Bomber |
Jack -- do those things, and you'll have narrowed it down greatly (and I'm betting you'll have started it, too) we've gotten spoiled by the electronic ignitions, I think -- spark, air, fuel and compressions are all that's needed, but the spark needs to be at the right time | ||
| Ceejay |
CactusJack-how goes it??? | ||
| Firemanjim |
Timing cup will not "dislodge" or drift a few degrees,it can break--done 3 of em,but you will have no spark.Now the timing plate may get lose and move a couple of degrees---There is no "pin" it is a machined slot on the cam IIRC.On mine anyway. If you have spark and fuel it should fire.Plugs new?? | ||
| Oldog |
Cjack: Have you tried to check for trouble codes? this is an EFI model, I know that this sounds weird but did the battery leads short when the battery was out? Lafayette reset someones EFI in florida doing this. Possible Problem, the Cylinder head temp probe in the rear head in the "chimmney" when Mine went I got a trouble light for a couple of seconds. Similar symptoms. If you have a shop manual the read back is covered. |
