DRZ 400 Carb Drain Leak

[-Monty-]

Hi all,

I have noticed the drain hose on my DRZ is leaking fuel. I took the carb off the bike and found the float valve was not sealing properly (blowing through the fuel pipe and air was getting through), so I ordered a repair kit from WeMoto and fitted it. Blowed through the pipe again and it seems the valve is now completely sealed

However, there was still fuel leaking from the drain pipe. There were only two more things I could think of to try; the float height, and whether the drain screw was actually sealing. After checking, both are fine, so I am pretty much out of ideas now. I did try fitting the old plunger into the valve as the button on top was actually a slightly different size to the new one, but it's still leaking.

Does anyone have any other ideas what could be causing this?

Thanks

Alex

EDIT: Forgot to mention it is the S model with the Mikuni carb.
____________________
Present: [Kawasaki ZX7r][Suzuki DRZ 400s]
Past: [Honda PCX 125] [Yamaha RXS 100] [Honda CB 500] [Triumph Speed Four] [Honda ST1100 Pan European - Po-Po Edition]

[jaffa90]

Still sounds like the carb is over filling, i would check the needle valve and the seat again for dirt. Also is the seat housing with filter sealed as well. I take it that the float floats and is set correctly!

[UncleFester]

Petcock seals gone?
____________________
Module 1 and 2 passed - October 2014. Happy owner of a 2017 Z1000SX, ex owner of a YBR125 / CB500 / VFR800.

[-Monty-]

[UncleFester]

you said your carb drain has fuel coming out of it? Fuel only gets into the bike from one place. you need to work your way backwards.

I only mention about the petcock seals as my mates bike had an issue similar to this and it turned out the carbs we're slowly filling with fuel when the bike was left standing.
____________________
Module 1 and 2 passed - October 2014. Happy owner of a 2017 Z1000SX, ex owner of a YBR125 / CB500 / VFR800.

[Irn-Bru]

Chuck it in the bin and put an FCR39 on instead
____________________
KTM 990 SMT & Suzuki DR-Z 400 SM

[jaffa90]

"""""""I will check this again, but it does seem like it is completely sealed as I can't get any air to come through the valve when I blow through it.

""""""
If it is completely sealed it would not overflow.
Also it should not overflow with a faulty petcock (fuel tap).

[Boddee]

Had a DRZ once, and had nightmares setting the needle height- Or even getting it seated well enough to stop the overflow (I think I needle filed the sides of needle ever so slightly because of very slight undulations down the sides of the needle)- It can be done though if you follow the Haynes Manual instructions and set the height correctly. Not to sure about how those pumper carbs work.

[Nobby the Bastard]

[-Monty-]

[Nobby the Bastard]

[-Monty-]

[Nobby the Bastard]

In that case fill the float bowl with petrol off the bike so that it doesn't reach the overflow. It it leaks its the drain, if it doesn't, lower the float a tad and see if it fixes it. I take it that you've checked that the float actually floats.
____________________
trevor saxe-coburg-gotha:"Remember this simple rule - scooters are for men who like to feel the breeze on their huge, flapping cunt lips."
Sprint ST 1050

[-]

I bought a Wemoto set of float valves for one of my TZR's. It was slightly the wrong length and never sealed properly when the floats were at full height. Fair play though, they refunded me straight away when I sent a photo showing the difference in length.

On my bike, it wasn't just the valves which were worn, the cup they sit in were quite worn too. I ended up going to Allens Performance and ordering a couple of matched cup and valve kits for my carb. Problem solved, but £30 a set from memory. (could have been a pair though).
____________________
TZR250 2MA road, TZR250 1KT road, TZR250 2MA race, TDR250, YZF-750R Boost colours.
Jaguar S Type 3.0 V6 Sport R, VW Transporter T5 GP LWB Shuttle 140ps DSG.