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CV carb won't feed fuel. Stumped.


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Bike was running okay and then stopped running suddenly, can't figure out what the problem is. Can anyone think of anything I'm overlooking?

2006 DRZ400S w/2001 E motor, stock S (CV) carb. 3x3, Big Gun Quiet Series mid-pipe and can w/ stock E header, 145 MJ, 25 Pilot, 4th clip on Dynojet needle, Keintech 2.5 turns out. On needle, starting from notched end: cap, spring, washer, clip in 4th notch, thicker metal washer, plastic spacer (is this right?). Breather vent on E intake manifold is capped with stock bolt. Fuel line attached between petcock and carb. Vacuum tube between petcock and top of carb (when mounted) attached. Vacuum nipple at bottom of CV carb capped with rubber cap. Breather hose out left side of carb is open and breathing.

Bike will crank with start button, but WILL NOT FIRE. Fuel flow good to float bowl. Spark plug works and dry, even after lots of cranking. Thus, apparently, fuel is not getting out of carb and into combustion chamber. Vacuum hoses appear to be installed, capped properly.

The jetting was off before it stopped running. It cut out and lost power in mid-high revs. Ran fine until throttle was open about half way. At WFO it pulls hard, without cutting out. So, essentially I have a patch at %50-%90 that cuts in and out on the highway at steady speed.

I tried moving the clip up to the second notch on the Dynojet needle, but it didn't work. I also went back to a 142.5 MJ, but that didn't work either. Before I had installed the 145, I had a 140 MJ, which worked but was weak. I still can't get the bike to start.

Because the bike ran, however badly, with the existing jetting, I'm thinking there's another problem besides jetting. It turns out that, when my bike stopped working, I had it parked so that when this industrial sprinkler system turned on, it shot water under my fuel tank and towards my motor for who knows how long. I have had a similar situation after pressure washing, but in case that is what caused the sudden failure to start, I've changed the spark plug, checked to make sure the lead was dry, made sure the combustion chamber was dry, made sure there isn't water in the oil. I've also taken apart the carb twice and sprayed the heck out of it with carb cleaner. The second time, I also removed and cleaned the main, pilot and that other jet right there, as well as the holes they were seated in, in case water got in them.

I can't think of anything else to do except start over and do all the same checks again, hoping I messed one up.

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simple test. remove air box door and and air filter.shoot a bit of cabr cleaner in intake.crnak.does it run for a second? if not youve got other issues.

jetting doesnt make a bike shut off and fail to start again after it was already running.

Thanks, Eddie. Yes, I tried the starter fluid: nothing. Odd thing is, it broke down at my new job on Friday. After a couple days of messing with it, it finally started and I thought everything was great. Ran fine all the way home. And then when I tried to start it up this morning, nothing. I have since tried starter fluid, and taken the carb apart and put it back together again after cleaning. The only other thing I've adjusted is the idle screw. I also swapped the gasoline, in case there was water in it.

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Valve adjustment needed? Took the odometer off awhile back on second motor with supposedly low miles. Should be quite a bit less than 10K on motor. Supposedly valve adjustments don't need to be made for 14K. This is a 2001 E motor--were they different?

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Valve adjustment needed? Took the odometer off awhile back on second motor with supposedly low miles. Should be quite a bit less than 10K on motor. Supposedly valve adjustments don't need to be made for 14K. This is a 2001 E motor--were they different?

and if your has lost intake valve clearance it will be just one of the many that quit running long before 14k.

14k is simply ridiculous.

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pull the stator cover to check to see if the starter clutch bolts backed out.

If the starter clutch wasn't engaging, wouldn't I not get spark or compression? Anyway, I'll pop it just to see. I did the Loctite fix, but I'll check anyway.

and if your has lost intake valve clearance it will be just one of the many that quit running long before 14k.

14k is simply ridiculous.

I read somewhere that that's Suzuki's recommended valve maintenance interval for the DRZ400S. In any case, I'll check the valves. Hopefully, I can make do with what few shims I have, because the only motorcycle shop in town just went out of business and I won't have other wheels until the weekend.

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If the starter clutch wasn't engaging, wouldn't I not get spark or compression? Anyway, I'll pop it just to see. I did the Loctite fix, but I'll check anyway.

I read somewhere that that's Suzuki's recommended valve maintenance interval for the DRZ400S. In any case, I'll check the valves. Hopefully, I can make do with what few shims I have, because the only motorcycle shop in town just went out of business and I won't have other wheels until the weekend.

If the starter clutch bolts back out they can damage the stator. Causes a no spark situation.

Suzuki has some unrealistic service intervals in the owners manual.

And, if it was a valve adjustment thing, wouldn't it still get my spark plug wet with gasoline?

If the intake valve isn't opening the fuel can't get to the plug.

Strike that. As I reread my post I found myself saying "What the hall was I thinking?"

Edited by GOF1
Brain fart!
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Starter clutch bolts fine. Right intake valve was at zero clearance. I hate it when the real problem is hiding behind a lot of red herrings: I was experimenting with the carburetion (and it sucked), I had a cracked nipple plug on the carb, I turned out to be parked with my motor in the jet of a high-power lawn sprinkler. Had plans for a week to go on a several day camping trip, and am instead broke and without transportation.

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