View Full Version : 1998 thunderbolt

07-10-2008, 02:59 AM
Have a modified thunderbolt hasn't ran in tree years. I can start it on start fluid but will not run from tank. Lines are clear vaccume piston works . poss vent problem or air leak ? also there is a componet missing. the negative wire is hanging just of to the Right of the battery. I have been working on this bike with my sportster manual(06) so if anyone has a thunderbolt manual or a line on one please let me know as my searches have come up empty at every turn. Also anyone know of an aftermarket tank that fits buell bikes. Love your buell and put it away panting, Phil

07-10-2008, 04:02 AM
Phuell, I also have a 98 S3, I would look at possibly rebuilding the carb, or at least a good cleaning. It sounds like there may be some gunk in the jets. As for the missing component it might be the flasher as that sounds like the location to the right of the battery, on a mounting tab. I do have the manual I'll have to dig it out.

07-10-2008, 07:54 AM
if it's still fuel injected, check the pressure.
if it's converted to a carb, a good cleaning would be a good thing.

for aftermarket stuff, you can check the usual aftermarket sites:
twinmotorcycles.nl (http://www.twinmotorcycles.nl/)
trojan-adrenalin (http://www.trojan-horse.co.uk/)
american sport bikes (asb) (http://www.americansportbike.com/)
ironmachine (http://www.ironmachine.com/)

07-11-2008, 03:09 AM
thanks for the info!!!

07-11-2008, 08:15 AM
no problem, hope it helps ;)

08-21-2008, 02:16 AM
Still no go . Replaced the carb (after rebuilding the original. because of a hole in the float bowl whith jb weld plugging it an grease covering it up ) Any way brand new carb. so I have been looking into the poss. of Starter interlock problems. Replaced Ignition relay
Again same (turns over but will not start) I did have to replace the battery due to an electric arc when I got the bike all the fuses were ok except one . My thoughts are diodes next. Also the faring is gone can I run a small tac and speedo on it and does anyone know the ratio for the replacement any suggestions think small and will siplifing the dash affect any systems I am overlooking? P.S. Could a faulty V.O.E.S. Cause this problem. Thanks Phuell

08-21-2008, 08:16 AM
- is the fuel getting to the cylinder (no obstruction in line or vacuum in tank)?
- is there a spark at the plug?

you can run any tac or speedo you want given the proper adjustments. there are even small digital aftermarket ones available.

08-22-2008, 08:36 PM
Like Lefox says,
Start with the basics. Now that you have it turning over.
Fuel, Air, Spark
Ensure that fuel makes it from the tank to the Cylinders, and that the spark is getting to the plugs. As for the Starting and Ignition, I have had the Micro switch go bad in the Clutch lever, that wouldn't allow me to start unless I was in Neutral. The VEOS is a strong Possibility, also check the Kick Stand Switch, if that is not working, the bike thinks the kick stand is down and will stall when you try to move it. Then check the Plugs, Coil, and Wires. If you still don't have juice then the ignition module or the timing pickup sensor under the round cover on the right side.

08-25-2008, 02:56 AM
Can you bypass this system w/out causing major elec problems?

08-25-2008, 03:14 AM
Lefox you had said to check spark at the plug. It backfires (50 Cal. Gunshot) so I had assumed that it was getting spark. I cleaned the plugs and adjusted the gap. I put a teaspoon or so of oil in and Put back the spark plugs. It should be getting fuel fine the carb and lines are all new. The carb Is a CV that is slightly different than the one I took out. It is newer (2005 or so) Is the Voes enough to run that Vaccume Or is there any diff. I may be overlooking?

08-25-2008, 08:26 AM
backfired in exhaust or carb?
timing could be off...

08-25-2008, 11:08 PM
Yes, you can bypass them but they were implemented to keep us from doing stupid stuff, Like starting the bike in gear without the clutch being pulled in, or riding with the K/S down. If you are a Competent Rider and be cognizant that you are not protected from yourself. Definitely check the Timing. Do you know how the bike was running last? I'll see if I can find the Schematic for the Wiring. The Vacuum from the manifold port should be plenty to work the switch. The last thing on the Backfire, it may be WAY too Lean, try to richen it up and see what that does.

08-26-2008, 03:23 PM
It backfires from the exhaust(loudly) I did use alot of carb cleaner and starter fluid could that have damaged the V.o.e.s. . I thought that the cam position sensor may be bad since it is part of the the suspect systems. from my description what can I rule out of the equation? As to ophawk Yes I have been riding for a long time so how would you bypass the Kickstand ,neutral and cluch swich the vaccume port on the carb is connected to a V.o.e.s. Are you saying I shuold reconfigure it to be more like my 06 sporty and upgade the sensor to to the newer ones that sit on the intake manifold. And how would it affect my computer system ? How do you check timing on a buell(never done timing on any bike)

08-26-2008, 05:09 PM
The old style timing light, magnetic pickup on the front cylinder. There is a port in between the V. They sell a Clear plug that you can put in it, to shine the light through, but I have only used it on an older HD a 78 XLCR that My dad owned. The timing marks are on the flywheel. You just check to see the marks in the little port, there aren't any reference marks like a car has. I'll have to dig my Manual out of storage, to give you the correct procedure. I did just see it the other day while I was looking for something else. On a 98 buell there wasn't much of a computer system, just an electronic ignition, similar to the GM HEI or most other mid '80's car setup. The VOES Needs full Manifold Vacuum to operate, its job is to check if the engine is running, if the kick stand is down and a load is put on the engine, the vacuum will drop, and the VOES will open and Kill the engine. I am work off my memory, I will get the manual out and get the schematic scanned and posted here tomorrow.

08-27-2008, 07:59 PM
OK, I have the Manual. The VOES Sends a signal to the Ign Module. at Hign Vacuum the Switch is Closed, at Low Vacuum it is open, The Ign Module selects which spark advance curve for those conditions. anyway to test the Ignition circuit.

Remove the White/Black tracer wire from the Ign Coil, attach a Test light or Volt meter to that wire and the other lead to a good ground.

Set the Kill Switch to ON
Turn Ign Switch to ON
Place Bike in Neutral
If Voltage is present, place the bike in 1st Gear
If Voltage is NOT Present, Retract the Side Stand
If Voltage is Present, Extend the Side Stand & Pull in the Clutch Lever
Is Voltage Present, Then the Ignition Power system is work correctly
If any of the above conditions are not correct then the fault is in that switch.

For Checking the Dynamic Timing of the Bike.
Hook the Pickup lead to the front cylinder plug
Set the engine idle RPM to 950-1050, or 200 RPM higher for Calif models
You are looking for two dots through the timing window on the right side near the base of the V.

Hope this Helps
I do have the Schematic of the wiring, I have it saved as a PDF, I'll get loaded soon

08-27-2008, 08:07 PM
Well Phuell, it seems that I can't figure out how to load a PDF into the forum, if you would like it Give me a PM at ophawk@gmail.com

08-29-2008, 05:58 PM
I now have the manual!!!! I had it running for a few seconds before I changed the carb. so it must be getting spark. exactly what/ where you saying to hook my vaccume line up to?

09-02-2008, 06:09 AM
A vacuum port that is on the back side of the throttle plate, showing engine vacuum, not ported as in only getting vacuum when the throttle is opened. You can test the VOES with a hand vacuum pump, to see if it is working the way it should, the procedure is in the Manual. I haven't seen the newer style carbs, so i'm at a loss as to where exactly you would hook it up to. On the original carb it should have been connected to the port on the top of the carb near the manifold base mount.

09-10-2008, 09:22 PM
It is ! I now have it started and running. Now however it builds up so much oil pressure that it shot the bung into 20 ft in the air along whith a fountain of oil. any advice on that?

12-23-2008, 01:42 PM
You have overfilled the oil bag/tank. Drain some out, restart the bike, let it get completely warm, shut it off and add oil ONLY until the level is between the marks on the dipstick with the bike level (NOT on the side stand) on the plus side3 you probably did not hurt anything except your your driveway...