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[jfw]

Was over in England last week and clocked up around 2,000 km almost without a hitch. The only hitches came as I was making my way back to a ferry and getting rained on in England (who'd have thought). I've had this problem for a while and failed to locate the problem but last week, in the rain, I think I found the reason for the problem if not the direct cause.

Basically the bike suddenly starts banging, spluttering and dies after some time in the rain, then it might eventually, restart, after a lot of kicking, but when you put it into gear and pull off it dies again. So been around a few things and decided that it must be water getting into the petrol. So last week on the side of the road, in the rain I dropped the fuel out of the carb float bowl. A few kicks and it was away. About an hour later in the rain we'd the same problem so dropped it again at the side of the road and off again.

So now I have the issue I have to sort out the source of the problem. Do all bikes have this problem or just my Bullet 500 with a KNR wire gauze air filter fitted? The air filter was on it when I bought it second hand. It's hard to see how the water's getting in when you're travelling. Maybe I need a snorkel Is the wire gauze not a good idea? Oh it's an Amal carb which I fitted, but used the air filter which was on the original carb.

[MickB]

I had a similar problem with my Triumph T100ss many years ago. The problem was that the rain was running back under the petrol tank and then seeping down the throttle cable where it entered the top of the amal carb. I fitted a rubber boot on the cable where it entered the carb and sealed it with some of that horrible plastic spray you could buy for sealing HT leads. Problem solved. The rain also used to run down the HT leads on the ditributor causing misfiring and sudden loss of power, a little drop of spray fixed that as well. Might be worth a try.

[Gwilly]

I'm of the opinion that normal running in wet weather shouldnt make much difference to a carb at half throttle say. Air/fuel mix being drawn in at a fair rate,water would have a problem finding a way into the float chamber. In fact have you ever noticed how a bike/car seems to pull better on a misty day...Something to do with water injection, but thats a whole new thread i guess.. Most problems will arise when bike at a stand still or parked... i used to carry a basin/bath plug to fit in the air trumpet if the beeza was left in the rain at work..... Its my guess that with various carb mods on your bike the coil has been left a little exposed to the elements and water is finding its way into the HT connection on top of the coil which points upwards on the enfield. Also any damage on the HT lead will become apparent when wet as its a long and torturess route to the spark plug,touching lots of metal bits enroute. Just sayin, cheers gwilly.

[Alan R]

Hi JFW ---first thing is to fit one of these in-line fuel filters.}----PART No. DESCRIPTION PRICE
90007 FUEL FILTER (CHROME), INLINE £8.25
------------------- They can be dismantled for cleaning. I use them on both my Classic 500 Bullets. Second is to discover just how water IS getting into the float bowl--( Your impromptu, "at-the-gutter" tests seem to confirm this to be the trouble). BUT-----you must now fully drain the fuel tank and dry the insides because water, being heavier than petrol, sinks to the very bottom and gives intermittent, nauseating problems.... Also consider having it lined against E10 fuel whilst the tank is empty... Re-fill with FRESH fuel from a proven moisture-free source. Also give your carb a strip & clean---just so you are at an known OK starting point.... As you've been experiencing this problem BEFORE you were out in the rain it makes me think that your fuel source could be the culprit ?? I'm not aware that Amal carbs can leak water INTO the float bowl---the float chamber air vents design tend to be free from this problem area. If you are using a Mk1 Concentric then why not try the Pancake-type air filter which uses a paper filament within a surrounding steel body ?? Looks very "period" as well. OR--- for guaranteed water-free air filtration the Tea-Caddy is just the job. I use a second insulator over the HT cable ( some air hose) with shrinkwrap to join this to the HT cap, and have put the HT coil into the L/H toolbox using an extended, copper-centred cable. A generous spraying of silicone helps as well. Finally---is the petrol tank cap allowing water in ?? Had you a tank-bag on top ?? Not trying to rub it in but a few years back, riding a Bullet 65 with these mods. done to it I rode from home here in Telford, Shrops. down to Reading, Berks. in POURING RAIN----for a short week-end visit to my parents---then back again in the same weather, giving a total of some 300 mile and it didn't falter at all. HONESTLY !!

[jfw]

Thanks a million for all that. There's enough for me to be getting on with.

I may have been unclear but the problem has happened before but only when I'm moving in the rain. I can leave it sitting for hours in the rain and it'll start first kick. But start it and ride if for an hour and we've got the problem. I'll have a look at the carb the air filter and the throttle cable which I never thought of. Maybe water is getting forced along this cable when I'm moving in the rain and down into the float bowl. I'd previously eliminated the coil from my inquires but I was sure it would be it. Sort of assumed the water could not get into the carb.

[Danish Dan]

Jfw.
I used to run a bellmouth on my micarb, but have very resently changed it for a teacaddy filter, because I got tired of walking in the rain. The symptoms was exactly as you described. A little rain was ok, but when it was pouring (or a big truck went past me) it came spluttering and banging to halt. After having emptied the floatbowl, everything was ok again. So I guess the engine can suck in enough water for it to be a problem.

[seen some changes]

To be honest, I would expect any water drawn in through carb would go straight into the cylinder rather than the float chamber due to the suction being created on the induction stroke. This only leaves water getting in from the tank as a possibility. As was previously suggested, drain the tank ,if possible into a clear container where it can be left to stand for a while and then if there is water there you will be able to see it.You can check the integrity of the cap while waiting for this to happen. I have ridden hundreds of miles in heavy rain and snow over the years on my two Constellations and it has usually been rain on the electrics that has caused me problems.If I fit new ht leads for any reason I always make sure both them and the distributor cap are clean and dry and then spray ignition sealant on the whole lot before putting cap back on. You can check your leads by running the back of your fingers along them while the engine is running and any leakage can be felt or seen by small sparks leaping to earth through you.If you are worried about doing this you can always get the wife/partner to hold your hand and then you can judge the amount of ht leakage in relation with how high they jump and also the names they call you.

[seen some changes]

P.S perhaps while you are draining the fuel any moisture is being dried out by the heat from the engine only to reappear once you are going down the road and the electrics get wet again so leading you down the wrong path.As previously mentioned , draining the tank would be a good idea as well to see if there is any water in there

[Phil666]

you have a wire gauze air filter.... well this will let you suck water into the carb as well. Put a pare element filter on with oil on the filter. Even better put an airbox on the filter so water cannot get in the catologue here has a number of choices and filter covers.Promise this will work.