Flat spot in throttle when pulling away fluttes at low speed 20mph or less dosnt run smooth at low speed this is a new triumph speedmarster with 700mils

scan it , it will tell you why.
if TBW fails throttle by wire fails speed is like 20mph max or less. on purpose., so scan it.
also if RPM is low foot ******* the throttle.?
then engine power lacks, scan it.
if RPM goes way high but MPH not same increase,the transmission is dead or slipping.

gear box damage is the real problem

fit new spark plugs

Most likely dirt or something on the pickup.These are electronic speedos and operate thru the computer.Pull the pickup out and clean it.Would but imagine is just plugged into transmission.

depending on mileage, but possible tune-up could fix it. if already done then check ignition coil pack and ignition wires also spark plugs, check vacuum hoses for leaks or porous, last injectors clogged - use some techron fuel injector cleaner (wal-mart has them). Also get the throttle body and iac valve cleaned by throttle cleaner . Also this other possibilities are to be checked and confirmed.:---- Engine running rough or misfiring can be cause by the following:

1.Defective spark plugs
2.Inadequate spark/coil, defective spark plug wire.
3. Lack of compression
4.False air leakage.
5. Faulty fuel injectors.
6. Insufficient fuel pressure.
7. Contaminated fuel.
8. EGR valve that is leaking.
9. Oxygen sensors.
10. Throttle position sensor.
11. Manifold absolute pressure sensor
12.Mass Airflow Sensor
13.Idle air control valve
--------- This should help.Keep updated.Thanks.Helpmech.

there should be 2 screw controls labeled "H" and "L"...these are the carb adjustments for low speed and high speed...you may need to adjust them to get the best possible response between low and high throttle performance...you only need to get it started and then slowly turn the "L" control until it idles smoothly..then move on to the "H" control and while going from low idle to high with the throttle trigger adjust it slowly until you get a good, smooth response from low to high

Have you checked your fuel floats ,You may be suffering from high speed fuel starvation .try adjusting you floats to allow the maximum fuel into your carbs with out over flowing .You could also check to compression on the cylinders ,you may have a compression problem at high speed ,and this will cause hunting untill your engine gathers momentum and drives through it .

You will find idle speed controllers in the area of the throttle plates. In order to work, air must bypass the throttle plates.

The low speed screw (air flow) will be the one the throttle plate arm rests against. The high-speed screw (fuel flow) will be closer to the cylinder, downstream from the throttle plate, nearer to the fuel supply line. Start with 1/2 to one turn out from lightly seated and go 1/8th to 1/4 increments, opening until the saw starts, idles evenly and runs well under a solid cutting load. Make sure the carb air filter, spark plug, fuel and carb are all clean! The carb jet tips should be sharp, even and smooth...no worn grooves or bent/broken tips. Two-cycle saw and garden tool engines should start quite easily (three to four pulls or even less) if the cyl. compression is good and they are adjusted properly.