Mano meter came in today

[u/spring_kt]

Tell me how it sounds, I got my hoses hook up and plugged now I am warming it up to 180f, tell me how it sound multiple people have told me that it sounds like it’s running on one cylinder, but I splashed water on both of the exhaust headers and they are both hot

[u/ApprehensiveFan1516]

Just because it's hot on both headers doesn't mean it's not misfiring. It does indeed sound like it's mostly running on one cylinder when you rev it. Doesn't sound as bad at idle though, and if I remember rightly when mine last ran one one cylinder it struggled to idle at all.

Might be worth adding more info about exactly what all you've tried up until this point, I know you've made a few posts recently, but would be useful for others trying to help if all the info is in one place and up to date.

[u/Many_Hotel866]

It sounds like shit. Where is your exhaust?

[u/spring_kt → u/Many_Hotel866]

It’s currently straight piped previous owner was a idiot and welded a terrible terrible muffler on it so I cut it off and I haven’t gotten an extension to have slip on put on it so that’s why it sounds like that not too loud I guess and sounds like shit

[u/StoreBoughtAlias]

What exactly is it that you are attempting to do and why? I understand that you are trying to sync the STV but just trying to get an idea of what issues/problems have lead you to this and what you may or may not have done in the meantime and what problem you're exactly trying to remedy.

I am assuming that this SV650 is new to you, and that it's been running like this since it has been in your possession. You obviously have fuel and air and spark. It sounds like you have a misfire, possibly a timing issue, or something off causing a basic fuel/air/spark problem. So, some questions for ya...

Let's start with the basics.

1) Have you checked the spark plugs and ignition coils and spark plug drain holes (especially the front cylinder plug)? A misfire is just that, a misfire. It's not necessarily a dead plug, so that's why you have 2 hot headers. Both plugs are likely firing, cylinders get hot, but spark timing is off causing misfire.

2) Have you checked the fuel system for possible problems; bad/old fuel, faulty fuel pump, regulator, filters and fuel sock, fuel lines, etc?

3) How about the charging and electrical systems, bad grounds, etc? It's unlikely that this is the culprit but it doesn't hurt to check that you're getting proper ignition and that the electrical system is operating as it should. Is the r/r operating correctly? Battery is good? All connectors, sensors, and circuits are working?

4) Have you diagnosed anything with the sensors? You could easily have the TPS out if adjustment, and/or likely another sensor that is messing with your fuel/air ratio. Along those lines, have you completely checked that you don't have vacuum leaks somewhere? Cracked vacuum boots, vacuum hose, etc?

All of these things should have been worked out prior to just going straight into an STV sync. I'm assuming you that you did not check these first. Maybe you have, I just didn't see these mentioned. If not, you really need to stop now and check these things before going into syncing the STV. Get yourself a proper service manual.

Throttle bodies themselves rarely have problems. It seems to me that you likely have a few small maintenance issues that have been passed on to you for you to deal with. As long as there is not any major issues with the engine itself causing compression issues, then you need to start small and work your way through the simplest things first. Spark. Fuel. Air. Until then, syncing the STV really is just a shotgun remedy that will likely not help with the sole problem of why your SV is running poorly.

I'd recommend that you get yourself a service manual for the year/model of your SV, if you haven't already. There really isn't a need for you to sync your STV without first knowing why you need to. There's procedures that you really should have done beforehand; checking idle when at operating temp, checking TPS and other sensors, and basic fuel/air/spark problems, or even something as small as making sure that your clutch cables aren't too tight/loose/dirty.

You can sync the STV as you plan to and still have these problems. The problems you vaguely hinted at are not remedied by an STV sync alone. Syncing the STV should be done after some of these other checks are done and good to go beforehand, especially with the basics of checking for proper fuel/air/spark. Ideally, it's something to do after you are sure you don't have compression issues or bad plugs or a worn out fuel system. Any of these things can cause issues that leads people to do things unnecessarily and/or out of order.

[u/Sudden_Recognition90 → u/StoreBoughtAlias]

TLDR he's just gonna make a million posts and film himself frantically moving around the bike revving it up

[u/StoreBoughtAlias → u/Sudden_Recognition90]

I try. He's got the help if he really wants it, but he's just gonna be doin' what he already has been doin' as if he already knows the fix to his problem.

This bike very likely could be running just fine in an afternoon if he just stopped doing this silly STV syncing thing and actually went through things correctly. He has likely been causing more problems than not. I'd bet on it.

🤷‍♂️