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Old 12-10-2019, 01:25 PM   #1
Owain
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M821 Damp Start issues or water in fuel?

Hi,

I made the mistake of leaving bike out in heavy rain after which it started sporadically running on one cylinder.

This seemed to clear itself after a few runs and i thought was all OK.

Then i got caught out again. But this time bike fails to start. Turns over splutters a bit. But fails.

Thinking this was damp electrics. Took fuel tank off and tried to get to top plug. But i doing so i took fuel line, ground and pump off. But also two rubber hoses at front of tank. Drain hoses? One of these seemed to be full of water.

Thinking back i think i have seen water sitting under petrol cap when i have refueled bike.

Is this a blocked drain pipe, ment to drain water from around petrol cap? Could i have water in fuel?


I charged battery and this made no difference.

Any ideas?

What would be wet fuel symptoms?

M821
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Old 12-10-2019, 02:23 PM   #2
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I’d expect the drain hose to be 2 into 1. One to drain water from round the filler, the other to vent the tank itself. If you open the cap while the filler neck is full of water, you’ll probably get some water in the tank. I wouldn’t expect a one-off of this happening preventing the bike from starting, as the fuel pump should stir up the tank contents quite effectively, although it may need to turn over a couple of times before it catches. Pretty much the symptoms you describe.
Also if the hose is blocked and the tank isn’t venting a vacuum may be preventing fuel supply. You’d likely hear quite a hiss on opening the tank as air rushes in if this is the case.

Last edited by slob; 12-10-2019 at 02:26 PM..
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Old 12-10-2019, 03:32 PM   #3
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I think you nailed it on the head.

The rubber drain pipe for the water ingress round the fuel cap was pinched. Probably had been since the bike was manufactured.

Have cut out pinched section of pipe and spliced.
Fuel is draining from pipe at this moment.

A long standing issue and with the amount of rain we have had recently. Hopefully not damaged anything else.

Hopefully clean fuel will fix problem.

Got some good picies, but upload sze limit stops me luploading.

Cross fingers.
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Old 12-10-2019, 03:36 PM   #4
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The photo thing is a bug in the forum software, post them elswhere (eg photobucket) and link to them using the image (mountain) button above the reply box.
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Old 12-10-2019, 08:08 PM   #5
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https://photos.app.goo.gl/EMPcNYqXaJzLA7e86
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Old 12-10-2019, 08:24 PM   #6
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Looks as though it had a bit of heat on it while it was trapped to have ended up like that
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Old 12-10-2019, 09:32 PM   #7
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Quote:
Originally Posted by Owain View Post
I think you nailed it on the head.

The rubber drain pipe for the water ingress round the fuel cap was pinched. Probably had been since the bike was manufactured.

Have cut out pinched section of pipe and spliced.
Fuel is draining from pipe at this moment.

A long standing issue and with the amount of rain we have had recently. Hopefully not damaged anything else.

Hopefully clean fuel will fix problem.

Got some good picies, but upload sze limit stops me luploading.

Cross fingers.
https://postimages.org is simple and works well.
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Old 12-10-2019, 11:30 PM   #8
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Interesting picture content though no wheelie bin in sight so probably something you photo-shopped up.

That pipes had a good squashing while getting hot hasn't it. The S2R I have had a set of siamesed drains like that but they didn't do too much as they pipework through the tank had got blocked with a mix of old paint, lacquer and washed off alloy oxide. Evil job to clear out.

I've never had any water related problems with any of my Monsters, even riding well more impersonating a boat in some floods we had a few years back.... except the bloody oil turning to mayo
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Old 13-10-2019, 09:55 AM   #9
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The pipe routing was as from the factory. So must have been like it for ages.

I remember seeing water round cap when filling up and ignoring it. These things always come back to bite you if you don't follow them up.

Btw. Photo only just missed the wheelie bins!!!
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