Bonneville America Forums Forums Technical Forums General Tech Problems with my TBA

My 2003 TBA (3000 miles) still doesn’t work as it should. It was purchased after not being ridden for approx 2 years and it was running only with choke on. Carbs cleaning brought a noticeable difference. When started, the engine ran much smoother and finally it idled without choke. But after a while it started acting almost as bad as before. Any slight throttle opening caused hesitation, backfire or stalling. So I dissembled the carbs once again, cleaned them although didn’t see anything wrong, check the fuel height and the same situation. I tried air-mix adjustments -3, 2, 2.5 turns but to no avail. Finally took the bike to a friend who runs an auto shop. He managed to adjust the carbs so that the bike ran without any hesitation but it was also only for a while. He checked the coils, spark plugs and determined that the left cylinder wasn’t firing as it should. Then he found out that one of the pins in CDI module was bent, so he straighten it up and it helped. The engine worked really well, no stalling and backfiring. I put maybe approx 50 miles and now again it doesn’t want to idle. Even on choke rpms jump up and down, has backfiring and wants to stall when touching the throttle without choke on. I checked the vacuum plugs, tried new ones, disconnected the TPS sensor, always the same. The bike is stock except it has triumph tachometer and inline K&N fuel filter. I called today a nearby triumph dealer if they had igniters and how much it would cost. They told me that they had never replaced any igniter only pickup coils. It seems strange to me after reading the posts about igniter breakdowns. Can my ignition module cause the problems? The bike when ridden pulls really strong only at lower rpms all the symptoms happen. I am considering selling it as I’m loosing the will to work on it. Thanks for reading this post

If your tach needle is erratic, then it's the ignitor. See if you dealer would be willing to exchange ignitors from another bike to see if it solves your problem. If so, then see if you can find one on eBay, or buy a new one for $500.
Before you use the replacement ignitor for too long have your dealer check the sensor/pickup coil gap. There is a service bulletin that suggests changing the gap on older bikes, such as yours, to extend the life of the ignitor.
Here is a link to a forum posting that will give you further info:

http://www.triumphrat.net/twins-technical-talk/74806-speedmaster-2004-out-of-warranty-4-15-08-a.html

Sounds like you have a vacuum leak. You stated your bike pulls strong but acts up in the lower rpms. That's where the highest vacuum is generated. You stated that you changed the squirrel condoms but did you inspect the manifold clamps for tightness and the rubbers themselves for cracks? What about where your manifolds bolt to the engine? It's possible that your "O" rings are missing or broken. Who knows what the previous owner did. http://www.bikebandit.com/showschematic/m17614sch566714 Here is a link showing the breakdown - note number 7. Also, is your Air Injection removed. What about the vacuum line running to it? Is it plugged?

Try spraying a little ether around the rubbers to see if they aren't cracked. If you have a vacuum leak, ether or acetylene or some other flamable will smooth the engine out.

WD-40 should work also, & it's a tad safer than ether & acetylene.

The air injection system is not removed and the vacuum line is plugged. I didn’t remove the manifolds. The bolts looked untouched and I just checked if they were tight. The rubbers are ok, no signs of cracks and all clamps are tight. Also that guy told me that the gap on pickup coil was 0.8. Maybe I’ll check it by myself tomorrow. Thanks for you advice.

The problem was a missing pilot screw in the right carb. I had a guy who adjusted the carbs and he probably turned out the screws too many times. Now I have new "d" shaped pilot screws and the bike runs ok. Thanks for any suggestions in this matter
I can see by the security bits that he probably tried to turn out the TPS sensor. I am trying to determine what is the role of the TPS on our bikes. The manual says not to remove it, if so, can it damage the sensor? Has anybody ever removed the TPS? I am so glad the bike finally runs strong. Best regards.

I just removed mine to solve an intermittant stalling problem. The bike runs fine with it removed. You should notice a big reduction in popping through the exhaust on deceleration. With no TPS in the system some of the timing maps will be missing but it doesn't seem to make a lot of difference on fuel economy or power. Note how the bike runs with it plugged in, then unplug it and try the bike again.