HELP: Very strange problem for any solvers - SV650.org

15-04-06, 12:03 AM

ok, I have a 2001 650 and it got snowed on. Directly following, it would not start it acted as if the battery just diddnt have anough kick to it. Every time I tried for the following few days the battery continued to seem weaker and weaker until it acted as if it were completly dead (and jumping it did absolutly nothing.) So I try to roll start it on a hill, which it did on the first try. However it ran very very poorly (just barely) even at full throttle and full choke(which were both required for it to run at all). Ok now here comes the strange part, I hit my front brake and all of a sudden the rpms jump like crazy but only for a moment. Yet every time I hit my front brake handle it starts to run better. I have been around engins my whole life, I am not a mechanic dont get me wrong but this is some crazy sh*t as far as I know. Does anyone have a clue as to what might be going on. Thank you very much for you input.

Thank you, Jason Wampler
p.s It has an after market 8 port carb, pipes, front suspension and throttle lock(all done bafore I bought it)

rictus01 · 15-04-06, 12:41 AM

water in the front plug!

you're only starting it on one cylinder (the back one), I'd hazard a guess the drain hole for the front cylinder (on the righthand side, sitting on the bike) is blocked, and you've got water in it, by appling the front brake it briefly allows it to fire on both.

A subject extensively covered on here previously, do a search.

Cheers Mark.

15-04-06, 08:39 AM

Quote:

Originally Posted by FUJIMOstepper

I hit my front brake and all of a sudden the rpms jump like crazy but only for a moment. Yet every time I hit my front brake handle it starts to run better.

Just a thought but could it be your throttle assembly? Might be loose (or buggered) it just seems odd that it works when you nudge the right hand side of the handle bar.

Good chance its what rictus01 said though.

17-04-06, 09:39 AM

I would hazard a guess that by applying the brake you are allowing current to flow to the CDI via the brake circuit that isn’t getting there (or enough) via the proper method. I have had a quick look at the wiring diagram and everything is so interlaced it is hard to say without testing.

I presume it runs better if the front OR rear leaver/peddle is applied?? If so then it is deffo a circuitry thing. Also (again looking at the diagram) does it only run better when in neutral?

To be honest if it was running fine before you left it, and it has just sat out getting cold and damp, then the most likely cause is wet or corroded terminals in the ignition switch. Get some WD40 in there and turn on and off lots. Also when running try wobbling the key a bit to see if this has any effect.

Also you might want to try unplugging and replugging the CDI (located under passenger seat).

Let us know how you get on.

p.s. the battery will probably need a good charge now, a weak battery can bring in all sorts of gremlins itself!!

Speedy · 17-04-06, 05:15 PM

Sounds like an Earth has gone(Negative)for the engine/ignition,and is finding one when you apply brake,as the switch for your brake light simply gives an earth to the B.Light circuit when the contacts of the switch are closed.

NedSVS · 18-04-06, 05:04 PM

The full throttle full choke thing makes me think fuel & not sparks. Sparks are in general either there or not and the battery problem may be a completely seperate coincidence. If you have a severe fuel starvation problem (say the vac pipe to the fuel tap was split, or blocked fuel filter for eg) and the fuel level was much too low; when you hit the brakes the fuel sloshes around and the engine momentarily picks up (the opposite happens when the fuel is too high; when you hit the brakes fuel shoots up the needle jet and kills the motor by flooding it). Anyway, perhaps a theory worth considering (I see you have 8 port carb {whatever that is} so I'm not sure if that makes any difference)

15-04-06, 12:03 AM	#1
FUJIMOstepper Guest Posts: n/a	HELP: Very strange problem for any solvers ok, I have a 2001 650 and it got snowed on. Directly following, it would not start it acted as if the battery just diddnt have anough kick to it. Every time I tried for the following few days the battery continued to seem weaker and weaker until it acted as if it were completly dead (and jumping it did absolutly nothing.) So I try to roll start it on a hill, which it did on the first try. However it ran very very poorly (just barely) even at full throttle and full choke(which were both required for it to run at all). Ok now here comes the strange part, I hit my front brake and all of a sudden the rpms jump like crazy but only for a moment. Yet every time I hit my front brake handle it starts to run better. I have been around engins my whole life, I am not a mechanic dont get me wrong but this is some crazy sh*t as far as I know. Does anyone have a clue as to what might be going on. Thank you very much for you input. Thank you, Jason Wampler p.s It has an after market 8 port carb, pipes, front suspension and throttle lock(all done bafore I bought it)

15-04-06, 12:41 AM	#2
rictus01 Member Mega Poster Join Date: Jul 2003 Location: South London Posts: 9,799	water in the front plug! you're only starting it on one cylinder (the back one), I'd hazard a guess the drain hole for the front cylinder (on the righthand side, sitting on the bike) is blocked, and you've got water in it, by appling the front brake it briefly allows it to fire on both. A subject extensively covered on here previously, do a search. Cheers Mark. __________________ Life should not be a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, in a cloud of smoke, thoroughly used up, totally worn out, and loudly proclaiming, 'Wow! What a Ride!

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17-04-06, 09:39 AM	#4
Blue_SV650S Guest Posts: n/a	I would hazard a guess that by applying the brake you are allowing current to flow to the CDI via the brake circuit that isn’t getting there (or enough) via the proper method. I have had a quick look at the wiring diagram and everything is so interlaced it is hard to say without testing. I presume it runs better if the front OR rear leaver/peddle is applied?? If so then it is deffo a circuitry thing. Also (again looking at the diagram) does it only run better when in neutral? To be honest if it was running fine before you left it, and it has just sat out getting cold and damp, then the most likely cause is wet or corroded terminals in the ignition switch. Get some WD40 in there and turn on and off lots. Also when running try wobbling the key a bit to see if this has any effect. Also you might want to try unplugging and replugging the CDI (located under passenger seat). Let us know how you get on. p.s. the battery will probably need a good charge now, a weak battery can bring in all sorts of gremlins itself!!

17-04-06, 05:15 PM	#5
Speedy Member Mega Poster Join Date: Apr 2006 Location: Biggin Hill,Kent Posts: 1,074	Sounds like an Earth has gone(Negative)for the engine/ignition,and is finding one when you apply brake,as the switch for your brake light simply gives an earth to the B.Light circuit when the contacts of the switch are closed.

18-04-06, 05:04 PM	#6
NedSVS Member Join Date: Mar 2005 Posts: 572	The full throttle full choke thing makes me think fuel & not sparks. Sparks are in general either there or not and the battery problem may be a completely seperate coincidence. If you have a severe fuel starvation problem (say the vac pipe to the fuel tap was split, or blocked fuel filter for eg) and the fuel level was much too low; when you hit the brakes the fuel sloshes around and the engine momentarily picks up (the opposite happens when the fuel is too high; when you hit the brakes fuel shoots up the needle jet and kills the motor by flooding it). Anyway, perhaps a theory worth considering (I see you have 8 port carb {whatever that is} so I'm not sure if that makes any difference)