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DRZ400s dies after getting wet

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I did not see this covered anywhere so I wanted to share it. I have had problems with this bike dieing after crossing water since I have had it. I read the threads about it and it always focused on the FCR carb. Mine has the standard s carb so that got ruled out. The bike died on me this weekend after splashing through a couple of small puddles. The bike died around the next corner. I tried to start it about 10 times when it would happen to catch it would only idle and would die as soon as I gave it any throttle. Got worried that I was going to drain the battery and decided to let it dry out. Waited about 8 minutes and tried it again and cranked up like it never happened, ran great the rest of the day. see video that was recorded of the failure here

The bike was covered with mud so when I got home I washed it thoroughly. Tried to start it after washing it and experienced the same symptoms. Let it sit and dry then it fired right up ran fine. Thought about it the next day at work and decided that when I got home I would spray the hose in different locations until it died and suffered the same symptoms. This test eliminated the carb as the problem, and indicated that something under the tank- an electrical connection most likely- was the culprit. Pulled side panels, seat and loosened tank until I could lift it and access to what I would call the coil that feeds the spark plug, and multiple other connectors. I then disassembled each connector individually drying with compressed air and applying dielectric grease to it and then putting it back together before going to the next connector (didn't take them all apart at the same time, one at a time to avoid confusion). Let it sit over night and I just tested it by spraying water under the tank and all around the motorcycle in general. Results were that it did die a couple of times when spraying directly on top of the carb, not sure if I was getting some mist in the air box (3x3 mod completed) or what but it started right back up and ran fine. It was just idling and I dont think it would have died if I had been riding with any throttle on. My bike details - 2004 drz400 3x3, drilled out end pipe stock exhaust, stator replaced before I bought the bike, other non mechanical improvments currently 9200 miles. Hope this helps someone diagnose their problem in the future.

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My fix did not work, connectors was apparently not the problem, or at least not all of the problem. I deduced this while my riding partner was towing me out of the woods with his KLR650! It started to die at every stop, then it just died. It now starts but will not stay running when given throttle. I am cleaning the carb now and will post what I find the problem was.

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My fix did not work, connectors was apparently not the problem, or at least not all of the problem. I deduced this while my riding partner was towing me out of the woods with his KLR650! It started to die at every stop, then it just died. It now starts but will not stay running when given throttle. I am cleaning the carb now and will post what I find the problem was.

Interesting look forward to what you find...

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Read this: (found on another site)

]Here's the most basic principle to understand about your carburetor. As air flows into a carburetor, the area available for flow narrows. For a given mass flow rate, this means that the speed of the air increases as the area decreases. Because of the decreased pressure in the throat, the atmospheric pressure can push fuel through the jets into the air stream. This is all assuming that the fuel in the bowl is still at atmospheric pressure. Thats what your carb vent hoses are for

If the vent hose to your carb bowl gets plugged up with, say, water, then you will no longer have the pressure differential needed to push fuel from the bowl through the jets. If this happens in a water crossing, this could be you]

Many bikes are prone to this problem unless you make a simple modification commonly known at theT-vent. The basic principle is to insert a T-fitting into your carb vent line as close to the carb as possible, and route an additional vent to an higher location on the bike. This will allow you to do deeper water crossings without plugging the vent hose, which is usually routed to the lowest location on the frame.

]Here are some links that may help

http://www.advrider....ead.php?t=98167

http://www.advrider....t=149009&page=2

I ran mine up under the gas tank to the steering neck and put a loop back done to under the tank. That way vented way up high and if needed had a siphon or extra fuel line.

From seeing what little water you was in this may not be it but an easy and cheap mod to do.

Edited by wingam00

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check your spark plug boot. if it has cracks, it can ground with very little moisture. a drop in the right place is enough. also check the plug wire and coil connection.

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check your spark plug boot. if it has cracks, it can ground with very little moisture. a drop in the right place is enough. also check the plug wire and coil connection.

Good point. One can take a spary bottle with water and mist the area of the spark plug and other electrical connections why the bike is running and that help find any problems.

Edited by wingam00

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Thanks for the responses. This was two separate problems apparently. I did have the problem where it died in water. I believe that is fixed. Got some bad fuel somehow which caused the carb jets to plug up. Cleaned the carb and found that it started too easily- no choke, and died the instant that it got to 1/4 throttle. Thought about it and wondered if I could have mixed up a couple of jets. Took it apart again and found that I switched the startup jet and the main jet. I didn't think that the engineers at Suzuki would have used the same size and thread pattern for these jets, but they did. My mistake for mixing them up- bang head. Took it out for about 35 miles of riding yesterday and all is well. I should hit the swamp this weekend and will test it out in the water. I have avoided the vent tube t fitting and routing under the tank or into the air box because I think it allows the water to get closer to the carb. Can water enter the carb through the vent if it tube fills up or is it only one way?

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Thanks for the responses. This was two separate problems apparently. I did have the problem where it died in water. I believe that is fixed. Got some bad fuel somehow which caused the carb jets to plug up. Cleaned the carb and found that it started too easily- no choke, and died the instant that it got to 1/4 throttle. Thought about it and wondered if I could have mixed up a couple of jets. Took it apart again and found that I switched the startup jet and the main jet. I didn't think that the engineers at Suzuki would have used the same size and thread pattern for these jets, but they did. My mistake for mixing them up- bang head. Took it out for about 35 miles of riding yesterday and all is well. I should hit the swamp this weekend and will test it out in the water. I have avoided the vent tube t fitting and routing under the tank or into the air box because I think it allows the water to get closer to the carb. Can water enter the carb through the vent if it tube fills up or is it only one way?

The idea is to route a least one vent line up high where it won't get submerged. For example, on top of the airbox. Now if you ride through water that'll get that high to clog the vent line, then water already would have been sucked through the air filter stopping the engine... So anywhere above the airbox is good, because that's about as high as water can get for the engine to still run.

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Rode through a ton of water today. drz did great until it really started getting wet. I hit one puddle going fast, and as soon as the water splashed up it died. Tested it when I got home. If I spray any water on the wire going between the plug boot and the coil. I'm going to try some heat shrink on it and see if that helps.

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Mine always acts up when it rains, always thought it had to do with my K&N filter letting water into the carb.

Edited by Moterreal

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Rode through a ton of water today. drz did great until it really started getting wet. I hit one puddle going fast, and as soon as the water splashed up it died. Tested it when I got home. If I spray any water on the wire going between the plug boot and the coil. I'm going to try some heat shrink on it and see if that helps.

take whatever your setup allows - apart - and silicon it back together. or just put a new plug wire on it and be happy.

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Oh good are you suggesting it is the plug wire? If so does a standard plug wire from an auto parts store work? Because I tested it again this week while washing it and It absolutely dies when I squirt a light steam of water on the plug wire/ plug. I was thinking about installing some heat shrink but if a standard spark plug wire will work ill t that first.

I was thinking it was the point where the boot and the plug wire went together.

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I had the samething happen to me one day I took my bike through Azusa river I slipped and dropped the bike in the river after getting the bike to the other side checked that there was no water in the air box, carb or in the engine oil started it up and it did the same hard starting with low idling and shut off when I would give it gas I just let it dry off for 10-15 mins no problems after that had a feeling it was something electrical now I know

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I just want to mention that I've had a lot of issues with the sidestand safety switch when riding off road that can give you similar symptoms. If your foot bumps the kickstand down a little, or the pit/creek/bump that you're wheelieing through is big enough, the bike will either bog or die when the sidestand isn't all the way up. think I might make a strap to keep it up while riding off road and decommission the safety switch...

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I just want to mention that I've had a lot of issues with the sidestand safety switch when riding off road that can give you similar symptoms. If your foot bumps the kickstand down a little, or the pit/creek/bump that you're wheelieing through is big enough, the bike will either bog or die when the sidestand isn't all the way up. think I might make a strap to keep it up while riding off road and decommission the safety switch...

Take it off and solder the wires together. Not many Dizzers left with them in place...

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LOL I wear a size 13/14 boot, That side stand kill switch did not last long with me, everytime I touched myh boot to the kickstand it would bog down. Clutch kill switch is gone also, it had to go so I could fit my GPS. I have zeroed in on the culprit, just not sure if I should replace the spark plug wire with an auto store part or heat shrink it. We rode through so much water this weekend and as long as I went slow enough that it didn't splash up under the tank area, it ran fine. I went through one puddle and splashed water under the tank and it was like someone hit the kill switch. At the end of this run we had to pull one of my riding partners DRZ440 out by hand, good thing there were 3 of us. :smirk:

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Problem fixed. I put some dielectric grease on the spark plug wire/boot/cover. Now I can spray water on the wire and it does not stall out. Now I get to change my rear wheel bearings.

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Tested it he swamp this past weekend. I went into a small pond that ended up being much deeper than I thought. Bike preformed flawlessly not even a hiccup. I cleaned my bike when I got home and later that night I noticed mud had dripped out of my air box onto the swing arm. The hole was even deeper than I thought it was. Had about an inch of mud in the bottom of the air box. Whew! I don't want to come that close to sucking muddy water into the engine again.

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