Dropping a cylinder in the wet

[J.M.]

I have no way to describe this other than the bike feels to be dropping a cylinder in the wet. The sound starts to sound all raspy, like the exhaust was blowing, and the idle drops from 1250 to around 500-750. However, once revved above about 5-6rpm, the other cylinder appears to work, although it then drops again when the rpm falls below about 3-4k. If you ride around the 3-5k rpm marker, you can feel the moment sometimes when the second cylinder kicks in, as the bike picks up power fairly swiftly with 0 throttle movement. Lunges forwards almost.

It first happened after performing an emergency stop in the wet a few months ago.

On dry days, the bike runs spot on.

Thinking it was an exposed wire somewhere, I stripped the bike down and re-soldered all joints and replaced all insulation tape with heat shrink. I also removed the wiring for all accessories, including heated grips. This seemed to have fixed it, as I was then riding in the snow with no problems. Most of the days I rode were dry since then, so I kind of forgot about it, as the problem never came back.

I just rode to Uni now in the wet and it happened again.

Any ideas what it could be anyone?
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2004 R1 & 2018 XSR900

[CaNsA]

Check the sparkplug wells for water.

[unitynotsocri...]

what bike?Broadly speaking it sounds like you've upset the grit and shit in your carb bowls,use the drain screws to give em a flush,after giving the bike a good shake.

Luckily I've never had this problem on my cg's,as the front drum brakes don't allow normal decelleration,hence the rust stays at the bottom of the float bowl.
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nearly a normal tax paying tosser.......with ferrileness suzi100,cg125,cb125scb100n,cb175,cd100,cj250t,kh250,c15,125 bantam,super 6,rickman gs750,xt500,250rs,dt175,lifan125,dolomite1850,metro,Morris220ld,morrisfg,leyland princess,range rover,corsa,vw camper .now struggling with legs. MORE ORDER = MORE CHAOS

[haroman666]

Does the GS have a hose that take spilt fuel from around the filler cap straight to the top of the Carbs? I know they share a lot of parts with the Bandit 4's and mine suffered in the wet because it just drained water from the filler cap stright to the top of the carbs. Just check under the tank and see how many hoses go from the tank to the carbs/inlet rubber.
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The mistresses: 2000 Honda CBR600f, 2000 Honda VTR1000

[J.M.]

GS500FK4. It's too intermittent to be carbs.

The e-stop was months ago. Probably 1.5k miles done since the e-stop happened and it never happens in the dry. Carbs were also last cleaned on the 16th Feb.

I'll check the sparkplug wells for water Although they are pretty shielded by the fairings, but I'll still check them.

Under the tank on the GS there are 3 pipes: 1 overflow/water drainage pipe which leads completely out of the bike. 2 from the tank petcock in to the main petcock (reserve and main) which then goes in to the carbs.

I just think it's super strange because it never happened before that e-stop. I mean, I was riding home in the wet a few months ago. Had to e-stop. Bike was running perfectly before, upon trying to accelerate away, it was on 1 cylinder.

The other thing to add is that when I got off the bike, it was just running on 1 cylinder. When I return to it about about 5-7pm tonight, it'll be running on both again. (That's what always happened before).
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2004 R1 & 2018 XSR900

[chris-red]

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Well, you know what they say. If you want to save the world, you have to push a few old ladies down the stairs.
Skudd:- Perhaps she just thinks you are a window licker and is being nice just in case she becomes another Jill Dando.
WANTED:- Fujinon (Fuji) M42 (Screw on) lenses, let me know if you have anything.

[Clutchy]

My mate had a GS that did this, not sure of the year though, and it was water getting into the spark plug/cap and a slight tear in the lower end part of the HT lead.

We worked it out by getting it to drop a cylinder in the wet, stop but keep the engine running, then sprayed WD-40 around the cap and the other cylinder fired right up.

Replaced HT lead, plug and caps and worked fine from then onwards.
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Malaguti F12 Phantom-Dead, Suzuki AY50- Dead, NRG power DD LQ, CBR125.
*33 BHP restriction up on 10/12/14* Current bikes/car: SV 650 S/ MKIV GOLF
Guide to pass your test with no lessons!

[Benson_JV]

Apparently happens quite often on the SV's, same symptoms as with your GS. Another shout for sparkplug wells / HT leads.
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Willson - "If you go out on that CBR600 in the winter, you're going to do more miles on your side than on your wheels."
Riding: CBR600FW Driving: Audi A6
Previous Bikes: '96 Bandit 600, '96 GPz305

[P.]

Find your coil, unbolt from the frame, clean it all up, all contact points, trim the HT leads, only a small amount off each end and refit.

[J.M.]

So it seems the area to check is coils/ht leads then. Bugger, they're a right pain to access

That's Sunday's job sorted then.

Cheers guys
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2004 R1 & 2018 XSR900

[haroman666]

I only said carbs cause I had similar sounding problems and ended up spend £££ on new coils/leads/plug caps/plugs and neeeeearly a CDI unit. Then I found out it was a case of removing the hose i mentioned and BAM. Job's a good'n.

But as you dont have the hose, i'll convert to the electrical side of things
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The mistresses: 2000 Honda CBR600f, 2000 Honda VTR1000

[J.M.]

Bah, barely made it home! Started off... not perfect but not too bad. By the final big hill near my house, I was struggling to hit 30mph with full throttle in 1st or 2nd gear; I think it was first gear.

Then I barely managed to accellerate from 5-10mph going up the slight incline of my drive using 3/4 throttle in 1st gear.

Misfiring like a bitch. Sounds like an open pipe harley almost, albeit much quieter.

Now to try and fix it in fuck all time as I need to make it to a band audition about 10 miles away on the motorway. Fark.
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2004 R1 & 2018 XSR900

[Vincent]

I'd check/replace the plug caps first, and make sure they're connected to the leads properly.
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Space Is Deep

[J.M.]

Well the plug caps appear glued on to the leads for some reason... unsure why.

Removed the fairings, started the engine. Seemed to be running alright. Poured water directly over th right spark plug/cap. Worked fine. Poured water directly over the lft spark plug/cap. Worked fine.

Still had half a bottle of water left so I just chucked it over the bike. Started bogging down. Tried inspecting what was wet. Found a few electrical connector blocks near the right spark plug. Have taped them up in insulation tape so see if that provides any results.

Out of time for trouble shooting tonight... let's see if it can get me where I need to go!
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2004 R1 & 2018 XSR900

[P.]

Let it get dry tomorrow. Remove the tank and cover the fuel pipe, tip water on each part.

Leave it on choke so it revs high, you'll notice where it starts fucking up then.

[J.M.]

Dear the cunt that designed my waterproof gloves: we have different definitions of waterproof. Yours is wrong. Sponges aren't waterproof.

Got there and back, just about. It's the right ht lead/coil that foobared. Decided I was being an idiot with my diagnostics...

Had the engine idling on the point where one clinder is just about to bounce in to life but then dies. RPM jumping between 1000 and 1250. Disconnected the right ht lead, steady idle of 1000. Connected it back up, lumpy again.

Will probably check eBay for a used lead/coil and fit it.
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2004 R1 & 2018 XSR900

[J.M.]

2x coils, leads & caps bought for £16.50 delivered.
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2004 R1 & 2018 XSR900

[unitynotsocri...]

measure the resistance on the coils,if it still fks up after replacing the coils/leads/plugcaps then I 'd suspect a cracking cdi unit or knacked/damaged trigger coil.
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nearly a normal tax paying tosser.......with ferrileness suzi100,cg125,cb125scb100n,cb175,cd100,cj250t,kh250,c15,125 bantam,super 6,rickman gs750,xt500,250rs,dt175,lifan125,dolomite1850,metro,Morris220ld,morrisfg,leyland princess,range rover,corsa,vw camper .now struggling with legs. MORE ORDER = MORE CHAOS

[J.M.]

[Captain Liberious]

I would say you've got water getting in at one of your plug caps. Had the same problem on a couple of bikes now, both times pulled the plug caps off, get any water out of them, spray with contact cleaner and put back together, wrap with copious amounts of insulation tape.
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A squid eating dough in a polyethelene bag is fast and bulbous, got me?

[unitynotsocri...]

as Captain Liberious,you've got water in addonoids or summat.

them connector blocks ,as well as letting in water can corrode to feck.

intermittent faults on ignition/genny circuits are rare and as other posters say,are enclosed and away from water.

Anything with a wound coil can fail intermittently,as the enamal insulation breaks down,but they usually settle quickly into ...bust....burnt out.

Connector blocks....scub em with a brass brush,blow em out and visually inspect....sometimes connector pins need a GENTLE squashing to make a better connection.Don't leave any metal brush hairs inside em!

Reccommend...you use your bike in the appropiate enviroment....e.g. a country where it does'nt pss down all the time.

Chin up.count your blessings.A freind has this top class chinese scooter.Problem is it does'nt work in the rain,no matter what we do!A chinese bike importer says that model never worked in the rain,but because it was a cheapo of the cheapo models,the origional chinese/asian purchasers did'nt mind!So they carried on making it.
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nearly a normal tax paying tosser.......with ferrileness suzi100,cg125,cb125scb100n,cb175,cd100,cj250t,kh250,c15,125 bantam,super 6,rickman gs750,xt500,250rs,dt175,lifan125,dolomite1850,metro,Morris220ld,morrisfg,leyland princess,range rover,corsa,vw camper .now struggling with legs. MORE ORDER = MORE CHAOS