Is the TSP ERM Worth It on a 2024+ KTM 300 XC-W TBI?

Is the TSP ERM Worth It on a 2024+ 300 XC-W, TE 300 or EC 300 TBI?

For most US owners of a 2024 or newer KTM 300 XC-W, Husqvarna TE 300 or GasGas EC 300 TBI, yes. The TSP ERM ($500, or $530 with the tune pre-installed) reflashes your stock ECU with a TSP tune built for these bikes, lets you adjust fuel, ignition, oil and power valve settings, and gives you a TPS reset and fault code reader in the same tool. It won’t fix a clogged spark arrestor, a bad sensor or poor warm-up habits, so check those first.

Quick Answer

• Worth it if: your bike feels soft or doughy down low, loads up, or you want to adjust the map yourself instead of living with the stock tune.
• Check first: TPS voltage, spark plug, fuel filters, spark arrestor and silencer packing, air filter and your warm-up routine.
• Price: $500 for the ERM only, $530 with your tune pre-installed by Slavens.
• Fitment: ’24-27 KTM 300 XC-W, ’24-27 Husqvarna TE 300 and ’24-27 GasGas EC 300 are all covered. No adapter harness is needed on these TBI models.
• Want more bottom end too: look at the TSP ERM Power Kit for 250/300, which adds a TSP head and an NGK Iridium plug.

Why the 2024+ 300 TBI Enduro Models Feel Soft, Load Up and Foul Plugs

The 2024 enduro 300s moved from TPI to throttle body injection with a 39mm Keihin throttle body and an electronic power valve. The ECU sets fueling from water temperature, air temperature, ambient pressure, crankcase pressure, rpm and throttle position, so the stock map and the sensors feeding it decide how the bike runs.

Two Stroke Performance describes the stock 2024 300 XC-W/EXC engine as very smooth but very soft at all throttle positions, and short on torque at low throttle and low to mid revs. Their tune for these bikes is crisper in some areas and richer in others, so it doesn’t just lean the bike out everywhere.

What owners report: On ThumperTalk, KTMTalk and Reddit, owners of 2023 and 2024 TBI bikes describe spooge, plugs fouling on cold starts, and the bike loading up at idle. Some of those same owners traced it to a TPS set too high, a crankcase pressure sensor hose problem, a clogged spark arrestor or fuel filter, or short warm-ups in cold weather. Several owners say the ECU runs rich when the engine is cold, which matches how these bikes use cold start fueling. These are owner reports, not factory statements.

What the ERM Changes on Your 300 TBI

The ERM plugs into your bike’s diagnostic plug and reflashes the stock ECU. You don’t send your ECU anywhere and you don’t replace it. Once the tune is flashed, the ERM can come off the bike.

• TSP Tune File: One free TSP tune file (2 maps) for your bike. On TBI models, the white (softer) and green (aggressive) maps are both tuned.
• Basic Tuning (standard): Fuel +/- 10%, ignition +3/-5 degrees and power valve +/- 10% by rpm and throttle. Power valve tuning is only on TBI models.
• Presets: TSP, Richer, Leaner and Softer presets so you can feel what a change does before building your own.
• Oil: Owners on ThumperTalk report adjusting oil injection and cold start fuel through the ERM on 2024 TE 300s.
• Live Data: RPM, throttle %, power valve opening %, throttle voltage, map choice, coolant temp, ignition advance and battery voltage on TBI models.
• Map Selection: TBI models can switch maps through the ERM without the OEM map switch.
• Fault Codes: Read and clear fault codes with one button.
• Service Functions: TPS reset, power valve reset, oil pump prime, fuel pump, ignition and injector tests.
• Back to Stock: The original map can be flashed back any time, and on TBI models it’s saved to TSP’s server when you pair the ERM.

TSP says every TBI bike needs its throttle adaptive value set at 0.40v, especially when getting the ECU tuned, and the ERM makes that a simple job. Without it, you’re back-probing the TPS wires with a meter and doing the reset sequence from the owner’s manual.

What the ERM Won’t Fix

A new map won’t cover for a mechanical or maintenance problem. Before you blame the stock tune, check these:

• Spark Plug: Look at the plug and replace it if it’s wet or fouled. Slavens carries NGK Iridium and standard spark plugs, and the TSP Power Kits ship with a BR8EIX.
• TPS: A TPS set off from 0.40v can cause loading, sputtering and stalling.
• Crankcase Pressure Sensor: Owners report CCPS hose issues on TBI bikes. If you replace the sensor or do a top end, Slavens has the Crankcase Pressure Sensor Hose Clamp for TBI ($2.25).
• Fuel: There are two fuel filters on these bikes. Owners also point out the pump pickup sits high, so a low tank can act like a fuel problem.
• Exhaust: A clogged spark arrestor or packed-out silencer will make the bike run poorly.
• Air Filter: Start with a clean, oiled filter. Slavens stocks Twin Air air filters.
• Idle and Warm-Up: Owners who stopped fouling plugs usually changed how they warm up the bike, giving it more time on cold start fueling before riding.

Who It’s Worth It For

• Trail and Woods Riders: If you ride low in the rpm range and the bike feels soft or loads up, the TSP tune is aimed right at that.
• Riders Who Wrench: If you want to set the TPS, read fault codes and make your own fuel and power valve changes, the ERM does all of that in one tool.
• Riders Building the Bike Up: Jeff runs the ERM with a TSP high compression head insert and an FMF Gnarly on his own bike. See the Slavens Mule 2024 KTM 300 XC-W TBI Build.
• Riders Planning a Head: If you’re adding a TSP head, the ERM Power Kit bundles the ERM, the head and a plug.

Who Can Skip It

• Happy With Stock: If your bike starts, idles and pulls the way you want after the basics above are checked, you don’t need it.
• Multiple Bikes, One ERM: The ERM pairs to one bike at a time. Moving it to another bike means a reset for a fee.
• Street Use: The ERM is sold for closed course competition use only and isn’t emissions or noise compliant.

Price and Options

The TSP ERM at Slavens Racing comes two ways:

• ERM Only ($500): You register the ERM, download your TSP tune and flash it yourself. TBI pairing needs an internet connection.
• ERM w/ Pre-Installed Tune ($530): Slavens registers the ERM, downloads and preinstalls your tune before shipping. Put your bike’s year, make and model and the tune you want in the order notes at checkout.
• Pro Mode ($50): Same limits as Basic but much higher resolution, with up to 5 saved profiles. Bought through your account on the ERM website.
• Pro+ ($165): Bought through your account on the ERM website.
• What’s in the Box: ERM, rain cover, handlebar mount kit and USB cable.

Note: Pre-programmed ERMs are non-refundable. All pre-programmed ERM sales are final.

ERM Power Kit for 250/300 ($820 to $850)

The TSP ERM Power Kit for KTM/HQV/GG 250/300 includes the ERM, a TSP Cylinder Head and an NGK BR8EIX Iridium plug. Pick the XC-W/EXC/TE/EC TBI head option, which fits ’24-26 KTM 250/300 XC-W/EXC, ’24-26 Husqvarna TE 250/300 and ’24-26 GasGas EC 250/300. Head inserts come in low, medium, high and very high compression, and the right one depends on your elevation and fuel.

Fitment for the 2024+ 300 TBI Enduro Models

The ERM product page lists:

• KTM: ’18-27 250/300 XC/XC-W/EXC, which covers the ’24-27 300 XC-W TBI
• Husqvarna: ’18-27 TE/TX 250/300, which covers the ’24-27 TE 300 TBI
• GasGas: ’21-27 EC/EX 250/300, which covers the ’24-27 EC 300 TBI
• Harness: Only ’18-19 TPI models, Sherco 300s and four-strokes need the adapter harness. The 2024+ TBI enduro models don’t.

Comparing the ERM to a GET ECU or other options? See Which ECU is Right for You?

Frequently Asked Questions

Do I have to send my ECU in to use the ERM?

No. The ERM connects to the diagnostic plug and reflashes your stock ECU on the bike.

Does the ERM have to stay on the bike?

No. Once the tune is flashed and saved, it stays on the ECU and the ERM can be packed away. You can mount it on the bars to watch live data while testing.

Can I go back to the stock map?

Yes. The original map can be flashed back to the ECU any time. On TBI models it’s saved to TSP’s server automatically when you pair the ERM.

Do I need a map switch on my 2024+ 300 TBI?

No. On TBI models you can change between the white and green maps through the ERM without the OEM map switch, and the map choice stays saved when the bike is off.

Can I use one ERM on two bikes?

Not at the same time. The ERM pairs to one ECU at a time, but it can be reset for a fee so you can pair it to another bike.

Will the ERM stop my 300 TBI from fouling plugs?

It can help if the stock map is the cause, since you can adjust fuel and cold start settings. If the problem is TPS voltage, a sensor, fuel delivery, a clogged spark arrestor or warm-up habits, fix that first.

How do I set the TPS on a 2024 300 TBI?

TSP says TBI bikes should have the throttle adaptive value set at 0.40v. The ERM has a TPS reset function that makes this simple. Without it, you need a meter to back-probe the TPS and the reset sequence from your owner’s manual.

Questions about the ERM or which setup fits your bike? Contact Tracy Nichols, Slavens Racing ECU and Suspension Specialist, at tracy@slavensracing.com or 573-864-0505.