I have a 2011 Monster 796 and when the engine is cold sometimes it will make have what I can only describe as a single cough in terms of the judder and the noise it makes, sometimes it feels like one cylinder is potentially meeting some form of resistance, as if potentially a valve gets stuck or is striking a cylinder, how do I determine what it is actually going on? The bike generally runs fine but will usually do this when cold and be fine after warming up, I feel it may also help that last summer the bike had an issue where it wouldn’t start when it got too warm, I sometimes ended up in a situation where if I’d been on a long ride it would feel as if there was resistance in the engine when hot and if I tried to turn over the engine it just couldn’t do it and once left a hour+ to cool down then it would be fine again and would fire right up. Bike is working but I’d love to try and diagnose and potentially permanently resolve these strange one off issues that happen sometimes. Really hoping a complete engine rebuild isn’t the only resolution to this. Thank you for any help you can provide.
Cough/judder sounds like ignition as it's so abrupt. Tough starting when hot sounds like starter motor laziness and/or insufficient current there. I strongly doubt that anything in the engine is slowing things down or in contact. A stuck valve is impossible with desmodromic valve gear unless the valve stem has broken which, again, I strongly doubt...
Thank you for your response, are there any particular methods I can use to test which of the ignition coils or cabling within the ignition system are going bad? Also, should I just replace the starter motor?
All depends on your electrical skills & equipment. Measure voltage at the battery first, key off, for a baseline then measure battery voltage during engine cranking (usually needs an analogue voltmeter for quick response), then voltage at the starter during cranking. That may show issues with earthing, condition of your battery cables and so on. Might help to determine whether your starter motor is getting what it needs. As for the judder - you'll need to swap out with good components, so ideally you need a friend with the same or similar bike, or shell out for a coil pack (not sure which type on your bike) as a first try. How are your sparks when the plugs are out - good & healthy? Old, dirty plugs? Check the plug caps and leads for general condition. Someone on here should pop up and tell you some other things to check...
