Bonneville America Forums Forums Technical Forums General Tech Bike cutting out

Hello,has anyone any ideas as to why my bike (2002) cuts out. It's not the ecu because I have two and it happens with both. I have replaced the pick-up coil, battery, checked all connections, drained and cleaned tank and petcock, checked float bowl for crud/water. Bike starts well and ticks over nicely then just dies after a varying amount of time. When riding it runs well but just dies, again after varying amounts of time. It doesn't splutter just dies.I wait for some minutes then it starts right up again, runs well then cuts out again! I thought it would be a fuel problem but surely It would run poor then cut out if this was the case. I am now thinking coils but would they both give up at the same time? I haven't yet checked the ignition switch (behind the battery box) Any thoughts? Thanks in advance.

Sounds like a fuel issue to me... check your carb bowl vent (overflow) hose for restrictions and your tank vent hose as well,

Have you removed the hidden fuel filter? If not that very well could be the issue. It is inside the fuel line at the junction between the carbs.

I've checked the tank vent and it's ok. I haven't removed the hidden fuel filter, looks hard to get at....can it be removed without taking off carbs? I'll check the carb bowl vent too. thanks for your inputs.

I managed to get the hidden fuel filter out (very fiddly!)There was a small ammount of dirt in the bottom of the filter but I don't think enough to cause the prob. I'll have to fit an in-line filter now before I can test it. Thanks again.

Still cutting out...doesn't sound starved of fuel. just had it idling for about 10 mins, idling fine then just stops...won't restart straight away.

check all the fuses, make sure non of hem have any burnt or brown ends on them that might give way when they get hot, kill switch for corrosion, kickstand switch, air breather hose from tank not pinched or plugged under the bike.

I had a Mustang that would do that. changed fuel filters, checked carb., changed the coil... It ended up being the part # tag on the fuel gauge sending unit got loose and would wrap its self around the fuel pick-up inside the tank, after awhile it would fall away only to be sucked up again. Granted the fuel pump was sucking this tag around the pick-up and on the bike it's gravity fed, but I would look INSIDE the tank too. Next time this happens, shut the petcock off and check for fuel in the bowls just to eliminate if any thing is wrapping it's self around your fuel outlet, like a piece of plastic wrap.

Still no joy...I replaced the spark plugs and the bike ran well..took it for a spin, no missing or cutting, left the bike for about an hour and when I restarted it ran rough again, however, I was able to restart it straight away.@Two wheeln......I have thoroughly cleaned the tank and when it cuts out there is still fuel in the bowls.@ edmspeedmaster....The fuses all look ok, checked kill switch....ok, breather hose ok, kick-stand switch ok......I'm still thinking coils but just doubting both would fail together
Thanks for your suggestions...I'll let ya know how I get on

Make sure the plug wires are seated fully and if they are maybe it is time for new wires since you had some limited success with new plugs.

Thanks Dog33....I'll replace HT wires....they're about 50 quid though!

I can't see two coils going at the same time. The pickup coil and or related wiring would be the logical choice but you already changed it. ECM usually causes 1 cylinder to die and you changed it. I'd check the safeties that kill the bike. Side stand switch for corrosion and if it is water soaked. Weak side stand spring. Loose wiring to the kill switch. And also the ignition switch. Saw a number of them fail (they are repairable if you can open them up). Saw the plug in to the switch cause a similar problem. Was just about to fall off causing a make and break situation.

Good luck.

Thanks Gregger,I'll try and bypass the side stand switch and take a look at the ignition switch (behind the battery box?) Ive ordered new coils and ht leads so I hope I haven't wasted my money!

Do one thing at a time and try it to pin down the problem,if you make more than one change at a time you won't know what made any difference.

Well........Got my new coils today. When I started the bike this morning it ran rough....changed coils over and it started, ticking over nicely with good response from throttle. Unfortunately it is raining today so I have to wait for a test run. I've got new HT leads on order too so may have wasted money! I'll keep ya updated. This is a great site, I,m glad I joined, such helpful folk. I hope I can give something back.
p.s...maybe only one coil failed which was enough to make it cut out and run rough?

You can lose fire on one jug and the bike will still run.

Hi Madduck, I had the same problem.
To prevent yourself from spending loads of money on parts that may not cure your problem.

Bypass the side stand switch with a jumper wire.
I did this, and have had no problems since.
Costs pennies ! worth a try at least.

The side stand switch only needs to momentarily fail and bike stops. The nature of the switch is such, that I couldnt test it for an intermittent breakdown under riding conditions. So disabled it to rule it out.
I was completely hacked off with the bike, it would cut out totally randomly, but managed to restart each time. Not a pleasure to ride.
I have covered nearly 10,000 miles now, since the bypass, and have been trouble free !!!

I think the spade connectors on the connector block are only 3mm so standard electrical crimp connectors will not fit.
I Hope this helps.

One thing though, ''REMEMBER'' !!! you have Disabled the switch ''BEFORE YOU RIDE OFF'' !!! ''Put your Stand up''!!

I thought my gearbox had expired, turns out, it was the stand scraping along the ground on left hander !!!

You can Reconnect the switch for Any Department of Transport inspections. (MOT Test UK)

Best of luck ;-)

I changed my coils and that was the problem...bike now running like a dream. Thanks for all your suggestions. good to know about the sidestand switch though KP66.

check to see battery connections are tight...

No worries Madduck.

Glad your sorted.

The battery connections were very tight Kaiser! Defo the coils...the ones I used are called ip, they are a cheaper copy of PVL...I,ve just done 100 miles with them and the bike is running very well....especially with my ignitech ECU!

figure out which coil was bad, toss it and carry the remaining good one as a spare when you roll cross country. But you've done that already...