Won't start / rough running / stalls

[sparkplug]

So...

Bike was working perfectly when I binned it in January and broke 7 ribs and knackered my shoulder.

It was still running after falling on it's side (LHS if that makes any difference) and I can't remember if I turned it off with the key or the kill switch but I know I turned it off.

It's sat since then and I'm strong enough now to get back on an ride it. Happy days

Charged the battery for a day and a half and tried to start it. A couple of half hearted attempts at firing and then battery went flat. I suspect it's stayed for too long with no charge and probably needs replacement.

Battery back on charge all day yesterday and this morning I went and got some fresh fuel. I drained the old stuff from the tank, blew the fuel filter out with some compressed air and got a few cranks and attempts at firing before the battery went flat

No worries - jump leads out and got it to stutter it's way into running with the choke on. It ran rough to start with and would die if I tried to give it throttle.

I remembered 'the pic' and the mistake you only make once and checked the throttle body cables hadn't become dislodged in the prang. All good there.

Second time around it wouldn't start with the choke but did start without it - but would die if I gave it any gas.

Started again and left it to idle and warm up a bit. Didn't sound too bad and I thought I'd let the fuel flush through.

After a bit it started to stutter and I gave it some gas. It didn't stall but didn't rev smoothly. A bit of blue smoke out the back wasn't a big surprise and didn't last long. Then it started to misfire. I think one cylinder wasn't firing and I got the 'pop pop' through the exhaust.

Eventually it stalled and wouldn't start (flooded perhaps?)

All of this time it was on jump leads connected to a running engine - despite which it still seemed to make an effort when cranking.

Any ideas what might be going on here?

 

[ThreeDawg]

How do you blow through the fuel filter - do you have an external one?

Obviously you need a new battery to begin with. Can't do any harm to replace plugs, check leads and caps, electrical connections at injectors and maybe even the tps. Who knows what took a knock during the off? Are your fuel connectors properly pushed together? Fuel pump OK?

Maybe a mouse got into your air filter box and is blocking it up...

 

[The Other PaulG]

Is it possible to get an air bubble in the fuel line that allows fuel to seep past but not flow properly?

 

[sparkplug]

How do you blow through the fuel filter - do you have an external one?

Obviously you need a new battery to begin with. Can't do any harm to replace plugs, check leads and caps, electrical connections at injectors and maybe even the tps. Who knows what took a knock during the off? Are your fuel connectors properly pushed together? Fuel pump OK?

Maybe a mouse got into your air filter box and is blocking it up...

Yes - fuel filter is external. Fuel connectors were removed in order to drain the old fuel out so I'm happy they went back properly.

A couple of sketchy 'o' rings in there but I've bought some replacements I'm going to fit in the next few days.

Pump seems to be OK. I removed the pipe on the back end of the fuel filter to check fuel was running though it - when activating the pump there was a noticeable increase in flow.

Haven't checked the air filter for mice but it's certainly worth seeing if there's any obstruction.

Electrical seems plausible so will try plugs and leads. I've never touched the TPS but have had a bit of a read about them. Think I'll leave that till last

Is it possible to get an air bubble in the fuel line that allows fuel to seep past but not flow properly?

Dunno it's a pressurised system though so I'd have thought that any air would get forced out during priming / running.

Front wheel is at the shop getting a new tyre put on so won't be doing much today but thanks for the suggestions of what to try.

 

[DrFarkoff]

Quite Possibly Hall sensors

You tried to start it with a Duff battery and the current surge likely gave them a wee cooking they don;t like low voltage (high current situations)

Whats the revcounter doing when you are trying ?? jumping about ?? Good chance it's hall sensors

Sorry but starting and ticking over without being to rev it is a sign of them failing

If you have checked Fuel supply .....

One thing The TPS is it possible it got a kicking ? Needs Reset (approx 0.38 (zero point Three Eight) volts to 0.4v )

And one last thing try disconnecting the Lamda IF it still doesn;t go after checking/resetting TPS

Do one thing at a time rather than a bunch and wonder what if anything fixed it

 

[sparkplug]

Yes - definitely need to take a logical approach to it.

Hall sensor would also make sense - but the rev counter didn't behave oddly so I'm not convinced that's the issue.

Might also try swapping the horn and fuel pump relays. I did a visual inspection of the fuses but will run a continuity test on them as well.

I've never tried cranking the bike over with the fuel line disconnected before. I must admit I was expecting a higher flow of fuel - but I don't know what's normal. There was a burst when I disconnected the fuel line, but it's a pressurised system so that seems reasonable. After that it was more of a trickle than a gush - but it was definitely flowing more with the engine cranking.

Reading up on old threads I'm also going to check the electrical connector for the tank and the battery terminals.

 

[DrFarkoff]

Hall sensor would also make sense - but the rev counter didn't behave oddly so I'm not convinced that's the issue.

It is not a prerequisite!

You did however continue to try to start the bike with a low battery and kept on grinding it over with the hope it would catch Didn;t you ??

 

[sparkplug]

Not really.

I knew the battery was flat so charged it for a couple of days before attempting to start.

It went flat again really quickly which confirmed my suspicion that the battery needed changing.

Since then it's always only ever been cranked over while connected to the battery of a running vehicle.

My plan is to start with the easy stuff first.

• Properly test fuses
• Try swapping horn/fuel pump relay
• Remove tank and check electrical connector
• Replace battery and make sure connections are secure
• Replace air filter

Then move on to
• Spark plugs
• Leads / caps

If it's none of that then I guess I'll have another think and see what the next logical thing to test / replace would be.

 

[DrFarkoff]

My plan is to start with the easy stuff first.

Remove and ground spark plugs (Jump leads are good for grounding the nut bit) and check for regular spark if any

Remove the Injectors back out of the throttle bodies and fit tank and pipework and spin over with Plugs not out for spark test

Those should be your first two tests to be honest

Good Luck

Pay particular attention to the spark test is it nice and regular and in rhythm with the engine?

It its like an Arc welder and all over the place you will have your answer

 

[Riceburner]

Just another thing to add to the list (although it should only have a minor effect, so probably isn't your issue): Check the fuel-tank breathers aren't clogged.

 

[sparkplug]

Those should be your first two tests to be honest

Good Luck

Pay particular attention to the spark test is it nice and regular and in rhythm with the engine?

It its like an Arc welder and all over the place you will have your answer

Makes sense.

Especially the part about not spraying a mist of petrol near a naked spark

I'm still going to check fuses and fuel tank connector first because getting to the spark plugs means removing the quite twisted crash bars. It's a job that needs doing but I know it's not going to be a 5 minute job. In fact I'm sure it's going to be a monumental PITA

Just another thing to add to the list (although it should only have a minor effect, so probably isn't your issue): Check the fuel-tank breathers aren't clogged.

Thanks - simple one to check. Added to the list.

 

[Bem]

Convert it in to a 1200WC ?

 

[sparkplug]

Wouldn't change the old nail for anything in the world

 

[Crackshot]

What was the issue on this in the end??

 

[Welshman]

If the TPS plug is dislodged or damaged it will start, but die with any throttle.

 

[Mad Hatter]

Had the same problem on mine a couple of weeks back after a major overhaul. It turned out to be one of the throttle cables unseated at the splitter box end, not the throttle body end. Fixed it by holding the throttle open at the handlebar and pulling the cable outer away from the splitter box. Heard a click when it slipped back in place. Couldn’t believe how bad it made the bike run. Maybe your cables got dislodged at the splitter end during the crash/recovery?

 

[jetjock]

Had the same problem on mine a couple of weeks back after a major overhaul. It turned out to be one of the throttle cables unseated at the splitter box end, not the throttle body end. Fixed it by holding the throttle open at the handlebar and pulling the cable outer away from the splitter box. Heard a click when it slipped back in place. Couldn’t believe how bad it made the bike run. Maybe your cables got dislodged at the splitter end during the crash/recovery?

This

 

[Mad Hatter]

So...

Bike was working perfectly when I binned it in January and broke 7 ribs and knackered my shoulder.

It was still running after falling on it's side (LHS if that makes any difference) and I can't remember if I turned it off with the key or the kill switch but I know I turned it off.

It's sat since then and I'm strong enough now to get back on an ride it. Happy days

Charged the battery for a day and a half and tried to start it. A couple of half hearted attempts at firing and then battery went flat. I suspect it's stayed for too long with no charge and probably needs replacement.

Battery back on charge all day yesterday and this morning I went and got some fresh fuel. I drained the old stuff from the tank, blew the fuel filter out with some compressed air and got a few cranks and attempts at firing before the battery went flat

No worries - jump leads out and got it to stutter it's way into running with the choke on. It ran rough to start with and would die if I tried to give it throttle.

I remembered 'the pic' and the mistake you only make once and checked the throttle body cables hadn't become dislodged in the prang. All good there.

Second time around it wouldn't start with the choke but did start without it - but would die if I gave it any gas.

Started again and left it to idle and warm up a bit. Didn't sound too bad and I thought I'd let the fuel flush through.

After a bit it started to stutter and I gave it some gas. It didn't stall but didn't rev smoothly. A bit of blue smoke out the back wasn't a big surprise and didn't last long. Then it started to misfire. I think one cylinder wasn't firing and I got the 'pop pop' through the exhaust.

Eventually it stalled and wouldn't start (flooded perhaps?)

All of this time it was on jump leads connected to a running engine - despite which it still seemed to make an effort when cranking.

Any ideas what might be going on here?

Did you get it fixed in the end?

 

[Cook1e]

Yes, please update us - I have similar problems.