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Hydro lock.... bent valve?

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I just pulled my DRZ out of the shed to prep it for riding season. Installed the freshly charged battery, turned the petcock to prime for a couple seconds, then to on, and fired it up.

It started up normally after turning over for a couple seconds. After idling for 20-30 seconds it started to sound a little rough. I pushed the choke back in and it died instantly. I tried to restart and nothing happened.... just a click from the starter. I recharged the battery thinking that might be the issue. No luck.

I pulled the tank and spark plug and turned it over.... top end was full of gas. I got all the gas out and put it back together. It turns over now, but wont fire up. Its definitely getting gas, and I installed a new plug. Im thinking bent valve... any other ideas before I pull the head off?

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I haven't drained the oil yet. Would gas in the crankcase keep it from firing?

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DON'T pull the head until you do some simple diagnostics! Highly unlikely that it was hydrolocked. Hyrdo locking usually destroys the con-rod, not the valves. To confirm if you have a bent valve, perform a leak-down compression check. This will tell you whether it's a valve ot not...it will even tell you which valve (intake or exhaust).

You mentioned that you changed the plug. Was it a new one or one that you had laying around? Make sure there is spark at the plug. Also, if your petcock is not properly working, you may not get fuel through the carb. In any event, the petcock should be swapped out with a raptor unit as the vacuum petcock will fail sooner or later - yours sounds like it already has.

Edited by Gary in NJ
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I haven't drained the oil yet. Would gas in the crankcase keep it from firing?

Yes, a crankcase full of gas can prevent it from running.

It is highly unlikely that there is any engine damage from being full of gas. This is very common, the float valve o-ring fails and let's the engine fill with gas. Change the oil, replace the o-ring and verify that your petcock is stopping fuel flow when in the on position with the engine off.
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I'm going to get a compression gauge and test it before I tear it down. I've dealt with the leaky float valve issue before, petcock was rebuilt last year and the O ring was replaced 2 year ago. Gas flows fine with the vacuum hose hooked up, stops if I unhook the hose. I only had the petcock set to prime for a few seconds. Top end was definitely full of gas. It seems to turn over really easy now, but that might just be my imagination. Spark plug is brand new.

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Nothing is wrong , with a good fully charged battery crank it over with the throttle wide open . It's just got fuel vapors all over and doesn't have enough air to ignite , you need to flush it out the extra fuel and vapors till the mixture becomes burnable .  To bend something it would need to be running and instantly ingesting a cylinder full of gas , like jumping into a lake with it running . You'll need to verify a bunch hasn't gotten in the oil but it doesn't always happen . I had to do this 3 times with mine , kept forgetting to shut the petcock off when my o-ring had gotten bad , I had a fcr to go in so I wasn't going to mess with the Mikuni again.. Just took 20-30 seconds of cranking and she popped off and slowly cleared itself up . Disconnect the fuel line so the fuel isn't still flowing into the motor and fix the carb o-ring besides the petcock.

I run Iradium plugs so they'll fire even when wet , can't say for sure if a normal plug will start the same as mine did , may need to take the plug out after a bit of cranking and dry it off with a few quick hits with a propane torch.

.

Edited by jjktmrider
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