flooding problem

Having trouble with a friends 00' drz400. It has an fmf power core exhaust and the power up jet kit. Its sat quite a bit throughout its life with very little maintenance, and was never winterized properly. The last time it was out when we stopped for a break the bike flooded and soaked the air filter with gas. We rung out the filter and continued riding. A little further into the ride we stopped again because it started running funny, he opened the gas cap but it created a strong vacuum and was hard to get open. After that it seemed to run ok the rest of the day. Since then I've cleaned the carb several times. Now when you shut it off it either soaks the air filter or dumps gas into the case. I'm not familiar with suzukis, but the petcock doesn't seem to have an off position...just prime, on and reserve. Any suggestions on where to go from here? I'm stuck and tired of seeing it sitting in my garage, lol.

Probably a failed vacuum petcock, disconnect the fuel line from the carb, with the engine off and the petcock in ON or RES no fuel should flow through. If it does, then you either need to repair the petcock (seals inside), replace with another vacuum petcock, or get a manual petcock.

Use a manual petcock and get used to turning it off ... Manually

You have a leaking float valve, likely the O-ring under the valve seat fitting is shot. VERY common issue

Sounds like the petcock is the place to start. Every time I pulled the carb I would have to jamb something in the gas line because it wouldn't shut off.

Any suggestions on where to pick up a petcock from? Local auto parts store or tractor supply?

Thanks guys...

Sounds like the petcock is the place to start. Every time I pulled the carb I would have to jamb something in the gas line because it wouldn't shut off.

Any suggestions on where to pick up a petcock from? Local auto parts store or tractor supply?

Thanks guys...

Ebay,  i got the yamaha raptor 660 petcock shipped for like 18 bucks,  its a direct fit,  has the ON/OFF/RESERVE feature that you want,  you will need to cap off the vacumme line at the carb tho.

+1

You have a leaking float valve, likely the O-ring under the valve seat fitting is shot. VERY common issue

 

Agree......I will be very surprised if this is not the issue....

 

A manual petcock is a good safety back up for when the bike is sitting, you just have to remember to switch the tap to OFF..... :)

Edited by Craigo 485sm

Manual petcock will take care of the flow to the carb, but it won't stop the carb float valve from leaking....which is where the wet filter and flooded gas come from.

 

As you know, the engine requires a regulated supply of fuel that is in balance with the air flowing through the carb

However... if another source of fuel is introduced....as it is with your leaking float valve, the engine will not run as it should. For the sake of a 25 cent o-ring your engine will be quite unhappy.

 

Your call, of course............

I had a flooding problem, too. My seat o-ring was so flat that the seat fell right out of the carb body, when the hold-down was removed. I thought it best to go ahead and replace the whole needle valve assembly because, in addition to the seat o-ring, if the needle valve tip is worn, that can be a leak point too.

 

I, also, installed a Raptor petcock.

Jallen,

 

You may also want to check your friends oil and make sure that gas didn't find it's way into the transmission.  Seems like most of the time when people discover the issue with the vacuum petcock, they also find that they have gas in their oil.

 

:ride:

I have the flooding problem on my 2008 DRZ00 SM as well - I have a flat FCR 39mm carb on it.

I replaced the float valve needle....but did not replace the seat o-ring - left it overnight and it still drips out of the overflow hose.

BTW, I also checked the floater for leaks - it is solid - I bench tested with fuel and warm water.

 

I moved to the petcock - there was a small but consistent drip from it when you remove the hose on the on/res position.  I went ahead and replace the two washers - the smiley face and the oring - Yamaha part numbers per another thread -

3AJ-24534-01

3AC-24523-00

 

When tested the petcock, these is still a drip in the ON/RES position...

 

Any help will be appreciated.  How does the o-ring seat look like and how do you take that out?

I have zero experience with the FCR, my o-ring reference was to the Mikuni. Maybe dig out a schematic and see if the FCR uses the same method of sealing the float valve seat?

 

I have no patience with the vac-operated petcock, the inevitable leak is only discovered when the engine floods badly. And, yes, I know that an off-on-res petcock can also leak....... eventually.

Thanks for all of the quick and helpful replies everyone. Looks like the carb is coming back off....

 

I'm sure gas has reached the transmission, it seems to be everywhere else.

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