Complete noob with a dead 2004 SV650S
 

Hey all,

First off, apologies in advance for the long post. I'm trying to give as much detail as possible to have the best chance of solving this.

In August 2011 (just after I passed my test) I bought an SV650S from my local dealer. It had nearly 17,000 miles on the clock and a 33bhp restriction fitted, and went through a "full service" and was MOT'd the day before delivery.

Without boring you with all the details as to why, the only times I got to actually ride the bike in the few days after it was delivered was when it was dropped off (I rode it about 30 meters into the garage) and about 5 miles down the road when I thought I was insured (avoid MCE at all costs.) Both of these times the bike started first time, sounded a bit hesitant and weak when it idled, but pulled away without any issues and revved smoothly. I noticed that it would stall very easily whenever I dropped the revs but this seemed to improve a bit when the bike was warm. After my 5 mile ride the bike felt nice and warm and was revving well, but when I pulled back into my driveway and slowed down to a stop the bike stalled again.

I had to leave the bike in the garage as I had to move away for university for the next 12 weeks. During those 12 weeks the bike was started a couple of times and left to idle for a few minutes. When I came back it was icy and there was snow everywhere so I could only start the bike up and move it forward and backwards in the garage, but I noticed it still stalled almost all the time when it was moved and the revs dropped.

Now that I'm home and the weather is OK I've tried resolving this issue. A couple of weeks ago I put new fuel in it and started it back up. It still idled badly (was hopping between about 800 and 1200 rpm) so I upped the idle speed a bit. The bike started first time after this and the idle sounded healthy. I rode it about for a few minutes and everything felt perfect. At no point did it feel like it was going to stall. Problem solved I thought.

The next day I went to start the bike and it idled like crap again, and initially didn't sound like it wanted to start at all. When it did start the idle was all over the place and it sounded like it was losing a cylinder or something (idle sounded weak, deep and rough, then every few seconds it would pick up and purr for a second before dropping back down again.) It had been raining so I thought it may have been the notorious front spark plug issue.

I took out the front spark plug and it was coated in a layer of black soot and was slightly damp. I cleaned it and made sure it was dry and put it back in. The problem was even worse after this, and I seemed to need to give it quite a bit of throttle to even get the bike running (and it died if it droped below about 2000 rpm.) And after it stalled for the first time the bike wouldn't start at all for the rest of the day.

Today I took out the rear spark plug and it was also damp with what I think is petrol and was coated in the same thick black soot as the front plug. So I cleaned the soot off, made sure it was dry, and put it back in. Now the bike won't start up at all (I can smell fresh fuel around the bike after I try though.) It's entirely possible that I screwed something up here as I'm a complete novice, but I followed the directions of the Haynes manual and did some reading before hand and can't see what could have possibly gone wrong.

I should point out that throughout this the bike has always seemed OK after around 4000 rpm. The revs still jump about a bit, but it causes no issues and feels powerful and smooth. I also put the bike into dealer mode (or whatever that diagnostic mode is) and it reported no problems.

Does anyone have any ideas or suggestions?

I may have some videos of the bike starting, running, and subsequently dying if it would be any help in diagnosing this issue. I had my POV running and I may have saved a few clips. I just want to get my first big bike out on the road. :(

Re: Complete noob with a dead 2004 SV650S
 

you need new spark plugs.

Ditto. Theyre not sparking strongly enough. Lack of power.

Re: Complete noob with a dead 2004 SV650S
 

+2

Re: Complete noob with a dead 2004 SV650S
 

The tickover will only be perfect when the engine is properly hot, but the symptoms you describe are consistent with the tickover being set incorrectly and the throttle balance and TPS adjustments are suspect too. The spark plugs may not be in good order, but it's hard to say from here, and as the bike was recently serviced I doubt that they're knackered, even if they weren't replaced they should have been checked/cleaned/gapped.
Yes, don't do any of the above again, it pretty much guarantees plug fouling, which is the black sootiness you found on the plugs. Clearly it is sometimes unavoidable, but as a general rule do not run the engine unless it will be brought up to full temperature. Clean and gap the plugs, then check or have checked the above areas.

As long as there are no fuel leaks its worth checking the spark on the crankcase after cleaning them to rule out new plugs.

Re: Complete noob with a dead 2004 SV650S
 

Knackered plugs can still spark in free air

Would it be worth doing to check the spark strength?

Re: Complete noob with a dead 2004 SV650S
 

I don't bother. Check across a big gap, like 1/4", to see if you got strength from coil. Too hard to tell with plug, better to just fit fresh and not mess about.

Unless it doesn't run at all, in which case maybe, but his runs at high rpm, which could be a weak plug too.

Re: Complete noob with a dead 2004 SV650S
 

Thanks for the responses guys.

After trying to start the bike again to no avail I took out the old sooty plugs and installed some new iridium plugs (not sure if they're any better than normal plugs but they were only about £6 for a pair.) The bike burst into life as soon as I touched the starter button and seemed to idle much better. Power delivery was smooth, the throttle felt good, and the bike seemed to operate just as I'd hoped. The only issue was that the bike stalled once again after I rode up a steep hill in first gear. I saw the revs drop below 1000rpm as I stopped and released the throttle, then the bike cut out (started fine afterwards though.)

Could this be some old fuel gumming up the system somewhere?

Or is this something throttle/TPS related?