SV650s, bogging, cutting out and running poorly.

Thom · World Chat Champion Joined: 24 Oct 2007 Karma :

As some of you may know my mates acquired an sv650s. its a 02 registered curvy and is carbed for those who dont know.

Anyway we went for a ride today after seeing his riding instructors bodge to the clutch cable, apparantly this was sticking but i dont think that was the case to be honest.

Anyway as we're riding the bike gets warmer as it should but begins to hesistate when pulling away, stalling regularly whilst waiting and cutting out when he goes to pull away quickly.

The bikes been restricted but i reckon the people he bought it from are cowboys as the bikes got some stupid issues with it. Im unsure if the bikes been restricted properly i.e different jetting installed where neccesary.

The symptoms to me indicate the bikes running rich or possibly flooding. it doesnt happen at high revs, only low and i noticed a small amount of unburnt fuel come from his exhaust whilst revving in traffic. We're going to check the plugs sunday, if they're rich would you guys say its safe to assume my thoughts on jetting are correct?

I'm going to suggest running the bike without an airfilter for a mile or so if the plugs are rich and if this is the case i'll install smaller jets. any furthur advice/know how/words of wisdowm please?
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Current Bike: 1996 Yamaha TRX850 (The Japanese-Ducati One).
Previous Bikes: 1990 Honda NSR125 'Rothmans' (The smoking one), 1990 Suzuki GS500e 'Caf? fighter' (The loud one), 1987 Kawasaki GPX400r (The quick one), 1997 XJ600s Diversion (The reliable one), 2000 Kawasaki ER-5 (The spontaneously combustive one)

MarJay · But it's British! Joined: 15 Sep 2003 Karma :

check the front spark plug cap is OK, they are notorious for picking up water from the front wheel. G had this problem on his road SV and a new plug cap fixed it IIRC.

Oh yeah, and don't run without an air filter. You shouldn't need to change jetting for a restriction anyway. I didn't for my VFR400, the only thing I had to do when I derestricted it was balance the carburettors. To me this sounds like a classic one cylinder misfire.
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British beauty: Triumph Street Triple R; Loony stroker: KR1S; Track fun: GSXR750 L1; Commuter Missile: GSX-S1000F; Cheap project: CBR900RR FireBlade
Remember kids, bikes aren't like lego. You can't easily take a part from one bike and then fit it to another.

Thom · World Chat Champion Joined: 24 Oct 2007 Karma :

IIRc some bikes do require rejetting (Although my divvy didnt either). however i'd completely forgotten about the sv misfire problem, is it a simply case of getting a multimetre out and checking the voltage at the front cap?
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Current Bike: 1996 Yamaha TRX850 (The Japanese-Ducati One).
Previous Bikes: 1990 Honda NSR125 'Rothmans' (The smoking one), 1990 Suzuki GS500e 'Caf? fighter' (The loud one), 1987 Kawasaki GPX400r (The quick one), 1997 XJ600s Diversion (The reliable one), 2000 Kawasaki ER-5 (The spontaneously combustive one)

MarJay · But it's British! Joined: 15 Sep 2003 Karma :

Thom · World Chat Champion Joined: 24 Oct 2007 Karma :

To be honest mate me and electrics generally don't get along. i can strip and rebuild everything on a bike now (given the time and tools) but bugger me if i can play around with electrics!

Ok so it's just the simple plug against cylinder head test. Im sure i can do that! Very Happy

Am i right in thinking some people apply high temperature grease around the plug cap/plug on the front cylinder of the SV to prevent moisture getting in?

Also, just how much moisture would need to be there to affect the bike like this or are you suggestions previous use in damp conditions may have caused potential damage? Im just curious because since february this bike hasnt seen rain.
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Current Bike: 1996 Yamaha TRX850 (The Japanese-Ducati One).
Previous Bikes: 1990 Honda NSR125 'Rothmans' (The smoking one), 1990 Suzuki GS500e 'Caf? fighter' (The loud one), 1987 Kawasaki GPX400r (The quick one), 1997 XJ600s Diversion (The reliable one), 2000 Kawasaki ER-5 (The spontaneously combustive one)

finpos · World Chat Champion Joined: 13 Sep 2005 Karma :

lonner · Spanner Monkey Joined: 09 Jan 2009 Karma :

G · The Voice of Reason Joined: 02 Feb 2002 Karma :

Popping and banging a bit at low revs?

Could be that someone's left a vacuum cover/tube off the carb - this was what mine was like when I first got it.
Look over the carbs and see if there's anything obvious that should have a tube/cover on it.

Thom · World Chat Champion Joined: 24 Oct 2007 Karma :

right tomorrow im going to go have a look at the bike for him, its not popping and banging really, the only times ive heard it pop are when its stalled and being restarted (So thats the additional fuel igniting from the cylinder/thats in the zorst).

I would like to think that it is the front cat/lead thats buggared so i'll go with this in mind. I'll check the vacuum fittings too whislt im on.

cheers guys, ill let you know how it goes.
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Current Bike: 1996 Yamaha TRX850 (The Japanese-Ducati One).
Previous Bikes: 1990 Honda NSR125 'Rothmans' (The smoking one), 1990 Suzuki GS500e 'Caf? fighter' (The loud one), 1987 Kawasaki GPX400r (The quick one), 1997 XJ600s Diversion (The reliable one), 2000 Kawasaki ER-5 (The spontaneously combustive one)

Thom · World Chat Champion Joined: 24 Oct 2007 Karma :

Turns out the airfilter hadnt been changed in what would easily have been 8000miles i'd say. it was all gummed up on the inside...

So i stabbed loads of holes in it with a small screwdriver and we went riding, seemed ok, still had problems because i was careful not to lean off the mixture but a new air filter is on its way!

Thanks guys!
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Current Bike: 1996 Yamaha TRX850 (The Japanese-Ducati One).
Previous Bikes: 1990 Honda NSR125 'Rothmans' (The smoking one), 1990 Suzuki GS500e 'Caf? fighter' (The loud one), 1987 Kawasaki GPX400r (The quick one), 1997 XJ600s Diversion (The reliable one), 2000 Kawasaki ER-5 (The spontaneously combustive one)

Nicky-Jano · Could Be A Chat Bot Joined: 20 Feb 2007 Karma :

flumpy7 · Could Be A Chat Bot Joined: 31 May 2008 Karma :

i had similar probs with my sv once. Took it to the mechanic and he said the carb heater had died, replaced it and everything was fine!

Thom · World Chat Champion Joined: 24 Oct 2007 Karma :

they have carb heaters?

In all fairness the carb heater (If they have one) wouldnt be affecting the running in this warm weather.
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Current Bike: 1996 Yamaha TRX850 (The Japanese-Ducati One).
Previous Bikes: 1990 Honda NSR125 'Rothmans' (The smoking one), 1990 Suzuki GS500e 'Caf? fighter' (The loud one), 1987 Kawasaki GPX400r (The quick one), 1997 XJ600s Diversion (The reliable one), 2000 Kawasaki ER-5 (The spontaneously combustive one)

Scotsman37 · World Chat Champion Joined: 17 Aug 2004 Karma :

Probably dirt in one or more of the carbs, or double check that your cable(s) are not clogged/rusted up as they may not be fully releasing once you let go of the clutch/throttle.

As others have said check to make sure your spark plugs, plus they are all identical, as I had a nasty surprise when a brand new Suzuki GS 08 came from the factory with a wrong spark plug for that model. First and last time buying a brand new Suzuki bike and quality was shit, as it had debrit in the carb which caused that jerking & stalling motion.

flumpy7 · Could Be A Chat Bot Joined: 31 May 2008 Karma :

Thom · World Chat Champion Joined: 24 Oct 2007 Karma :

Its almost summer Razz

It CERTAINLY wasnt carb icing.
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Current Bike: 1996 Yamaha TRX850 (The Japanese-Ducati One).
Previous Bikes: 1990 Honda NSR125 'Rothmans' (The smoking one), 1990 Suzuki GS500e 'Caf? fighter' (The loud one), 1987 Kawasaki GPX400r (The quick one), 1997 XJ600s Diversion (The reliable one), 2000 Kawasaki ER-5 (The spontaneously combustive one)