ReptileVPK

2 NGK XD05F 5ohm spark plug caps, generic spark plug wires and the original coil! Before i rebuild the carbs, i thought the coils were making the bike run weird (turned out to be the carbs). These were second hand, an apparently were slowly dying. Put the original coils in which came with the bike, and voila!

Fixed! I changed te plug boots, coil wires and used a different coil. And now it's fixed!

Thanks for responding Hairsy. I started with an all original size overhaul kit. So all new parts, in pristine condition. Problem was there, and now slowly ironing out the kinks. But there are still a lot of kinks to be ironed out.

Hello forum members, A few months ago, I bought a 1992 Yamaha TDM 850 3VD. It needed some work since, after about 20 minutes of riding, it started stuttering at low RPMs and wouldn’t accelerate properly. When giving throttle from idle, it would "hiccup," as if it was skipping a stroke. The spark plugs were pitch black, and the internal carb components (throttle tubes, etc.) looked somewhat worn. So, I fully rebuilt the carbs (using parts from carburateurwinkel). The carbs weren’t split, but every possible jet and component was replaced. I also installed a used ignition coil, as that was my first suspicion. It seemed like the problem was solved, but unfortunately, the hiccuping returned. Once the engine gets properly warm, it struggles between idle and around 3,500 RPM. Adjusting the needle position and mixture screw didn’t help. Installing a larger pilot jet (from 37.5 to 40) improved things slightly, making it run 50/50. Now, the issue is random and unpredictable—it just comes and goes. Sometimes it stalls when taking off, other times I can’t keep the front wheel on the ground when accelerating. I have a USB hub (don’t worry, the issue was already there before installing it) that displays battery voltage, and this voltage remains unchanged whether the issue occurs or not. Link to the issue in action: https://youtu.be/Z_LdBUApUQw In the video, I'm at full throttle the entire time. The bike stutters and bucks up to around 3,500 RPM, and then suddenly kicks in like crazy. After that, you can see the throttle response. Current setup: Stock air filter Stock exhaust Valves adjusted 500 km ago Needle clip: second lowest position Pilot jet: 40 Main jets: 75 and 140 Air jets: 1.4 and 70 Mixture screw: 2.5 turns out Spark plugs: 500 km old (look a bit too white, in my opinion) You’d think it needs an even bigger pilot jet, but why? Nothing has changed that should require a larger one. Could this be an ignition problem? But if that were the case, wouldn’t I hear backfiring from the exhaust? In the video, you can hear popping from the intake instead. I'm also planning to install a GPR 2-1 Trioval exhaust, but only if I can fix this issue first. Help!