🛠️ Sea-Doo Speedster Starter Motor Troubleshooting: Why My New Starter Didn’t Work

Things were heading in a good direction! But then—new day, new curve ball. I took the boat down to the water for testing, excited to see both engines roar to life. But the starboard engine wouldn’t crank at all.

So it was back on the trailer, back home, and time to investigate.

If you’ve ever replaced a starter motor on a Sea-Doo Speedster only to find the engine still won’t crank properly, you’re not alone. I recently went through a frustrating starter replacement saga that ended up being a valuable lesson in diagnosing electrical issues on boats with Rotax 787 engines. Here’s what happened — and how I finally fixed it.

🔧 Symptom: No Crank or Very Slow Crank After Starter Replacement

I ordered a replacement starter motor for my Sea-Doo Speedster, installed it, and… nothing. Or rather, it cranked slowly—barely moving the engine. My first thought? Electrical issue. So I checked the basics:

• Fully charged battery ✅
• Clean terminals and tight connections ✅
• Voltage at the starter terminal ✅

Still, the same problem: no proper crank.

⚡ Voltage Drop During Start

I performed a voltage drop test while cranking, and yep — there was a noticeable drop. But it wasn’t due to poor wiring. The starter itself was pulling serious amps, even though it wasn’t turning the engine over properly. That told me something was off internally with the starter.

🔄 Tried Another Amazon Starter – Still No Luck

To rule out a bad part, I ordered a brand new starter motor from Amazon and installed it. Same issue. Slow crank. No start. At this point I was second-guessing everything—was it a bad ground? Seized engine? Faulty solenoid?

Nope.

🔁 The Known-Good Starter Test

I decided to pull the known working starter motor from the other engine and install it in the same position. Result? Instant, strong crank. No hesitation. No voltage drop beyond normal under-load conditions.

That confirmed it: both new starters were junk.

✅ The Fix: Don’t Trust Every New Part

The issue wasn’t with the battery, wiring, or grounding—it was the starters themselves. Despite being brand new, they couldn’t handle load. Whether they were poorly built or defective from the factory, it’s a reminder that “new” doesn’t always mean “good.”

---

🧠 Key Takeaways for Sea-Doo Owners:

• Always perform a voltage drop test when diagnosing starter issues.
• If you’re seeing a high amp draw and no crank, the starter might be the problem—not the wiring.
• Consider swapping in a known good starter to verify the issue before chasing phantom faults.
• Be cautious when buying aftermarket or budget starter motors online—performance can vary widely.

---

🔍 Common Searches This Might Help:

• Sea-Doo Speedster no start after new starter
• Rotax 787 starter motor replacement problems
• How to test a bad starter on a jet boat
• Amazon starter not working Sea-Doo
• Voltage drop when starting Sea-Doo engine