Why Won’t This 1975 Yamaha TY250 Trials Bike Run? (Low Compression, No Oil?!)

In this video, we dig into a non-running Yamaha trials bike that should fire—but doesn’t. It has spark, but we’re dealing with low compression, a dirty carb, and even signs of little to no oil in the engine. So what’s actually stopping it from running? We go step-by-step through diagnosing the issue, checking compression, inspecting the carburetor, and figuring out whether this engine is salvageable… or completely worn out. Essential items for this work (paid links): Tesla Borescope: https://amzn.to/3SnKVfw JIS Screwdrivers: https://amzn.to/4eneAOG MityVac Compression Tester: https://amzn.to/4uY1n3W ► TIkTok:   / 2stroketwinz   ► Instagram:   / 2stroketwinz   ► E-mail for Business Inquiries: 2stroketwinz@gmail.com Is it something simple, or are we looking at a full rebuild? 0:00 The 1975 Yamaha TY250 Trials "Beast" 0:50 Jen’s Motorcycle Knowledge Quiz 3:45 Dry Tank & The New Petcock Problem 5:30 Compression Test: 100 PSI?! 8:45 Checking for Spark (One Out of Three) 10:15 Jen’s "Yooper" Hat & UP Stories 12:45 Carburetor Takedown: "Like Butter" 16:30 Inside the Float Bowl: "Morning Yellow" Gas 18:45 Jet Cleaning & Surgical Carb Work 23:00 The Enrichener vs. Choke Debate 29:40 The "Drilled Out" Main Jet Mystery 36:45 Checking the Oil Injection Pump 44:15 Adding the "Yamalube" & Mixed Gas 47:40 First Start Attempt (The 23-Kick Struggle) 50:30 The Petcock "Amateur Hour" Realization 52:00 IT LIVES! 250cc Trials Sound Check 54:30 Greg’s First Trials Ride (Don't Hit the Flowers!) Follow along as we troubleshoot this Yamaha trials bike and see if we can bring it back to life. If you enjoy small engine repair, barn finds, and revivals, make sure to subscribe and follow along.