A couple of new issues on SV650

[Lukich]

Hi. I have an 2005 SV650 that I've been riding several times a week for the last year and a half. I try to keep it in a good shape, most of the work is done by me, but I try to stick to maintenance schedule as much as possible.

Recently it has developed a couple of new symptoms, I was wondering what they might be pointing to:

1) If my bike is cold and I start it up, the startup procedure is nice and snappy. However, if the engine is warm and I start it up, it's weird. I'm not sure how to describe it, but there is a lot of sputtering happening, the engine starts up much faster, but it feels like the starter doesn't disengage as quickly as it should? It's gotten a bit worse to a point where my bike died on startup once or twice. However, when the engine is cold again - no problem.

2) My bike started shifting from first to neutral when I turn the throttle slightly. So far, it doesn't happen when I ride, only when I'm just starting up, but it's unpleasant.

For those who encountered these issues before, what should I be looking for? I don't want to take it to the mechanic, I want to learn how to do it myself, but I'd like to do some research first.

Thank you!
Luka

 

[motomania2007]

1) cold start v warm start differences can be a lot of things: valves out of adjustment, vacuum leaks... just to name a couple.

2) shifting from first to neutral? Are you saying you are starting in first and it just shifts to neutral? You are holding the clutch in?

 

[dmfdmf]

1) Tight exhaust valves will cause hot start issues but they'd have to be very tight to exhibit symptoms. Don't run it unless you know the status from a recent gap check as tight clearances can burn a valve. Also, a 2005 may not have a gas tank evap canister (required in CA) but if it does check that its working right or it can cause hot start issues as well.

2) No idea. Adjust/lube the shift linkage?

 

[Lukich]

1) cold start v warm start differences can be a lot of things: valves out of adjustment, vacuum leaks... just to name a couple.

2) shifting from first to neutral? Are you saying you are starting in first and it just shifts to neutral? You are holding the clutch in?

1) I'm right at 15K which is the time for valve adjustment. I guess I need to do it ASAP.

2) This symptom usually manifests around might son's school. I park on a small incline to drop him off, with my rear wheel been lower that the front one. I then start feathering the clutch and slightly rolling the throttle to start moving and a couple of times my transmission just dropped from first to neutral.

 

[Lukich]

1) cold start v warm start differences can be a lot of things: valves out of adjustment, vacuum leaks... just to name a couple.

2) shifting from first to neutral? Are you saying you are starting in first and it just shifts to neutral? You are holding the clutch in?

1) Tight exhaust valves will cause hot start issues but they'd have to be very tight to exhibit symptoms. Don't run it unless you know the status from a recent gap check as tight clearances can burn a valve. Also, a 2005 may not have a gas tank evap canister (required in CA) but if it does check that its working right or it can cause hot start issues as well.

2) No idea. Adjust/lube the shift linkage?

Two people mentioning valves. I guess I need to adjust them soon. Thank you!

 

[ST Guy]

It's a good idea to check the valves, but if that doesn't do it, check for vacuum leaks. That happened to my ST once. All of a sudden it wouldn't run for shit until it warmed up all the way. It would fire up just fine, but not be able to take any throttle without killing the engine. I suspected a vacuum leak but never did find an actual cause. What I did, though, was to remove all the smog plumbing with its hoses and vacuum operated valves and the PAIR system which injects air into the exhaust ports. After that, it ran perfectly and I surmised there was some part of the smog system that was leaking air into the engine and leaning out the mix.

 

[motomania2007]

Vacuum leaks are easy to find: start the engine, let it idle, then use carb cleaner, wd40, starter fluid, etc with the sraw attached and make pointed squirts at vacuum connections, vacuum hoses, intake manifolds, ends of shafts in carbs/injector bodies, vacuum plugs, etc.

BE VERY CAREFUL YOUR SPRAY IS FLAMMABLE!

A vacuum leak will present itself when squirting the leak causes the engine to stumble or race.

Smog stuff can cause these issues as described above as one or more component can start to leak. Your bike is 13 years old and hoses have a service life.

If it we're my bike, I would check everything for leaks, then replace all the hoses anyway.