99 Sprint ST, Engine Cutting off at lower RPM's.

Hello All. My first post here. Hopefully I will give you all enough information for some good answers/advice. I have a 99 Sprint ST with 17300 miles, one of the early models (084XXX on the VIN, i've never had to learn the last three). I love the bike so far, got it only a year and a half ago and it has been running great until just last week.

Just recently my baby has been acting up on me pretty badly. She starts just fine and idles just fine for a while. However, I am not able to ride due the following issues: Take mind that these seems to occur in no particular order, other than it starts and idles fine at first:
1. The engine will idle fine after starting it.
2. The engine will usually cut off completely either when I put the bike in gear, before letting out the clutch. Or shortly after when attempting to get off the line.
3. The bike may or may not start again immediately afterwards.
4. If it does not start it usually will not even turn over. As in extemely low battery or something shorted or opened. Sometimes the lights will all go out as I attempt to turn it over.
5. If the bike didn't start immediately, usually within 10 seconds it will start turning over again and will start. On occasion when attempting to start the engine will turn over very slowly as in dying battery, maybe one or two turnovers every second or two. But a few seconds later after turning over slowly she may turn over just fine...and usually does, but then the entire process repeats itself.

I replaced the spark plugs with NGK iridium about two months ago. Cleaned out air filters, etc, changed oil about 3 weeks ago. Replaced chain a few weeks ago...(i know those don't matter, but just trying to show I try to take care of her as much as I can right now).

I have performed the following trouble shooting:

1.Battery measures 12.3v. At engine idle the voltage across the terminals is measuring about 12.5. At above 2000rpm it measures around 13.75v.
2. When the engine shuts off, if the engine will not turn over right away, I can usually hear the fuel injection system pressuring up (that little whining noise on the left just under the seat, then a click after a about 3 or 4 seconds).
3. I checked the three relays just under the right seat and swapped them around, since it seems the first is the fuel injection system pressure or something since it would not start when I took that one out. This had no effect, (I was hoping it was something simple like a relay)

Any information will help at this point. I can't even get it to my dealer to get it diagnosed at this point (Erico Motorsports, about 30 miles away), I have no way of getting it there and I can't even get the bike off the line right now. I am wasting valuable riding days here and starting to get pretty cranky about it...

Sorry the post is so long, but hope it helps with enough information.

TIA!!

[thfwsf]

There may be a simple answer. it sounds like the kick stand switch may be going bad. The bike shuts down when shifting out of nuetral if the sidestand is deployed. If the bike thinks the sidestand is deployed it will also kill the motor, even though the sidestand is not deployed. I would check this out first.

Tom

Thanks for the input thfwsf , but unfortunately the problem is not quite that easy...but it isn't too hard either, it is a switch, just a much more important one. I just need to figure out how much this is going to cost me...

The problem was getting worse as I was attempting to figure out the issue. So here it is...

Apparently over time the cluth cable, wrapping around the front of the frame, was rubbing on the wire patch going into the key switch right at the bottom of the housing entrance. This caused the wires to start breaking. But they were only open when the cluth cable was being used. Finally after a while of trying to figure out the issue, the problem got worse and was starting to occur even when I tipped the bike onto the side stand or turned the front wheel. If it hadn't gotten worse I am not sure I would have figured this one out any time soon.

Now I just need to figure out how to replace or fix the key wiring...has anyone done that? I guess I will call the dealer in the morning and see how much this is going to cost me. At least it isn't something worse, like ECU or EFI or something to that degree. I feel much more confident about Triumph now, I was starting to lose a little there trying to figure this out.

Thanks again for the help.

[Pwdrhd]

Actually I had the same thing go wrong only different symptoms. You may check with the dealer because I think they may have had a recall concerning that issue.

If not what I did and I will say my memory is fuzzy as it was 2 or 3 years ago is took the key switch out of the triple tree (yes I did have to take the top of the triple tree off). There are some special break off nuts that hold the switch either in the triple tree or hold it all together.

Basically I used some vise grips to take the switch apart and then bought the bottom half of the switch with the wiring harness used from Baxter Cycle in Iowa and then put it back together. I think they may have even had the special nuts.

The correct way would have been to replace the switch but that would have been $$$$ and I already have 3 keys and didn't want a 4th one.

Sorry I can't be more specific. I do remember a bit of figuring out but once I got into it, all was well.

Good Luck!
Scott

[motersikelist]

I had the problem but it wasn't caused by the clutch cable but by the previous owner. To tidy things up they had taken out the slack with a tie wrap. You can remove the ignition switch easily after removing the top tree clamp. To access the connectors in the bottom of the switch, place a small ball bearing or BB in each detente and tape in place. Use a hose clamp to apply pressure at all three points and it pops off. After that it's just electrical repair. Good luck.

Thanks for the info. I have gotten it fixed. I had a couple of wires that were just about severed just below the harness entry into the switch. I just cut it a little below the breaks and they and resoldered it.

Thanks again for the help. I got the wiring finished last night and will be putting my baby back together tonight (I decided to do a general cleanup while I was at it) and should be riding tommorrow! (weather permitting)