Bang!

[joshmac]

I've got a curvy 650s, 2000 model.
Got a set of tyres fitted on wednesday, picked bike up on Thursday
I went out for a long ride yesterday to scrub the tyres in and my bike's been backfiring loads (obviously this has nothing to do with the tyres!!)
When I picked it up, the bloke said it was runny very lumpy and I should get it serviced (probably through them :rolleyes:)

It doesn't backfire when I shut the throttle off, but when I'm accelerating and hit any sort of bump in the road..
Revs drop for a sec, then BANG (sometimes BANG BANG BANG :shock:)
Did it mid-corner and I nearly shat myself

Was running fine when I dropped it off on Wednesday
So what needs doing to get it as it was, before it was in the garage?
I'm guessing a carb balance? How much would a garage charge to do this?
Might be due an oil and filter change (which I should be able to do myself!). Could that be a contributing factor?

Also coincidently,? my alarm is now not working, but that's another issue

Thanks in advance,
Josh :smt090

[embee]

Sticking chokes?

[joshmac]

Sticking chokes?
How do I check for that?


Thanks for the reply btw :)

[Blue_SV650S]

If it is over bumps, sounds like it might be the sidestand switch or a loose connection on the coils, possibly one of the plug caps has popped off the top of the plug.

You can get to the front plug cap easy enough ... give it a push down to ensure it is seated correctly :)

[joshmac]

If it is over bumps, sounds like it might be the sidestand switch or a loose connection on the coils, possibly one of the plug caps has popped off the top of the plug.

You can get to the front plug cap easy enough ... give it a push down to ensure it is seated correctly :)
Cheers Blue, hadn't thought of that

*off to give it a push* :D

[yorkie_chris]

Loose connector.

[ricky_t]

I had something similar.

It was my reg/rec and a knackered battery.

Get a multimeter and check it is not charging up and 20v etc.

When my reg/rec went the bike felt less responsive and then would backfire loads a mate said he could see flames from the exhaust.

I have a new reg/rec with fan and I have never had a problem again.

[joshmac]

I had something similar.

It was my reg/rec and a knackered battery.

Get a multimeter and check it is not charging up and 20v etc.

When my reg/rec went the bike felt less responsive and then would backfire loads a mate said he could see flames from the exhaust.

I have a new reg/rec with fan and I have never had a problem again.
Thanks. I will borrow a multimeter tomorrow and test it.
How would the battery being knackered make it backfire?


EDIT: Just realised I can't check the reg/rec with the engine running.. my alarm has decided to pack itself in.. the fobs aren't doing anything, so I can't mobilise my bike :smt090

Anyone got any suggestions?
I assume you need the engine running to check the reg/rec

[plowsie]

Could be a wire earthing itself...

EDIT: It won't/shouldn't be the reg rec...all electrics would die, on my black sv i used to be able to flash the lights and make it backfire :lol: I can see where that may come from but i'd say it wouldn't be that josh.

[adamsimmons]

I had a similar problem to this not so long ago, and I know it sounds wierd but it ended up being the stand switch and front brake light switch. It was causing a short on the ignition circuit and causing the bike to cut out every so often, more often in the wet first of all then did it all the time until it kept on blowing the ignition fuse as soon as it was started. I replaced both of these and haven't had a problem since, been running fine now for 2 weeks with out a hiccup.

I hope that this helps

[joshmac]

I had a similar problem to this not so long ago, and I know it sounds wierd but it ended up being the stand switch and front brake light switch. It was causing a short on the ignition circuit and causing the bike to cut out every so often, more often in the wet first of all then did it all the time until it kept on blowing the ignition fuse as soon as it was started. I replaced both of these and haven't had a problem since, been running fine now for 2 weeks with out a hiccup.

I hope that this helps
Would it actually cut out long enough for you to have to restart the bike, or was it just for a split second before backfiring?

[joshmac]

It won't/shouldn't be the reg rec...all electrics would die, on my black sv i used to be able to flash the lights and make it backfire :lol:
:lol: That sounds cool.. Flash bang :p




It won't/shouldn't be the reg rec...all electrics would die...

That's what makes me think the reg/rec is OK.. lights, horn, indicators etc all appear to be fine.

Do you think it's possible that it's all down to the alarm.. immobilising for a split second, causing it to backfire when it reignites.
And now just packing up all together?
Surely if this was the case though, I'd have to disarm it with the fob (which I can't do ffs), no? :confused:

Cheers

[yorkie_chris]

You have an alarm that won't let you start the bike, and random electrical gremlins.... I would suggest the two are related. I'd start by lobbing the alarm in a skip and righting any damage done to the loom by the alarm fitter.

[joshmac]

You have an alarm that won't let you start the bike, and random electrical gremlins.... I would suggest the two are related. I'd start by lobbing the alarm in a skip and righting any damage done to the loom by the alarm fitter.
I've started thinking this myself.
Wouldn't really know where to start (as I'm sure you realised when I was trying to restrict my bike :lol::rolleyes:).. I'm guessing take pannels off, follow the wires from the alarm and then, Just remove them?

Would this definitely "re-mobilise" the bike?

[yorkie_chris]

Basically alarm cuts into several circuits and puts itself there as an extra switch.

To do it right you need to be able to solder, and follow wiring diagram. It's a bit of a pain of a job (ask melody about that one before NW3 hehehehe)

[joshmac]

Thought it'd be better to dig up this thread than start a new one...You need to find out where as it may be a chaffing wire. It could short out again or may even cut right through the wire when your miles away from home.

Don't leave it to chance Josh, have a dig around and find the offending connection or wire!

Regards


I'm afraid to say that you were correct (not that I doubted that at the time)
Riding back from Soho on Friday the backfiring/revs dropping/ cutting out have started again.

When I had the bike in pieces before I checked all the wires the best I could, but couldn't find the suspect.

Could it be the sidestand switch causing these erratic backfires? If so how would I check this?

:help:

[BBadger]

Wondered where you got to on the A3.
If you think its the side stand, find the contract and follow the wires around to see any breaks or lose bits.
If your still having troubles give Riverside motorcycles a call and ask over the phone, that could give you a better idea, or i can pop in an ask some time this week if you want ??

[vzzzbuxt]

silly but sidestand switch? is the sidestand loose and when you hit a dip it moves and loosens off the sidestand switch causing the engine to temp stop as thinking sidestand down, then as comes back up engine fires up and ignites the unburnt fuel-bang-

had a similiar prob years back with a gsx400- new sidestand spring cured it

[joshmac]

silly but sidestand switch? is the sidestand loose and when you hit a dip it moves and loosens off the sidestand switch causing the engine to temp stop as thinking sidestand down, then as comes back up engine fires up and ignites the unburnt fuel-bang-

had a similiar prob years back with a gsx400- new sidestand spring cured it
Will have a look when I get home. I hope it's that simple :)

[yorkie_chris]

Just bypass the switch

[custard]

just for my own curiosity.

did you buy this from a dealer?

[joshmac]

just for my own curiosity.

did you buy this from a dealer?
Nope.. Would've been back the first time it happened if I did

[joshmac]

Just bypass the switch
I'm not 100% that it even is the sidestand switch...

[yorkie_chris]

So? It'll eliminate it as a potential problem

[joshmac]

So? It'll eliminate it as a potential problem
True :D