Leaking Carb

[wedoo2]

I am new to the forum,and glad to be here.  I am working on an 08 DZR400S and cannot cure a leak I am getting from the carbureator.  It is coming from the two holes at the bottom of the intake side on the picture below.  I have removed the carb and did a thorough cleaning, even though it looked great.  Have reset the floats at 13.5 as I read in one of the posts here.  I reset the pilot to 2 1/2 turns out as that is how it was set before.  If anyone has an idea where to go from here please let me know.

 

 

 

Here is a look inside the bowls.

[Noble]

"2 holes bottom of intake side"  I'm guessing the air jet feed passages where air enter the carb picture 1.  You are on the right track.  The only way for those passages to weep gas is if the fuel level in the carb is too high. Float setting or float valve is the problem.  Float setting - set with the float contacting but no depressing he spring loaded top of the float needle.

 

More likely is the float valve is leaking.  Might be the tip of the needle is warn or degraded by current fuels, might be foreign material in the float valve.  My bet is you need a new O ring on the float valve seat.  Use a Vition rubber O ring 1/16" by 5/16" ID.  It fits tight but works well.  Use some silicone lube to help install the seat with the new O ring.

 

Have you tested the gas tank fuel petcock to assure it shuts off fuel when the motor is not running?  Usually gas leaking out of the carb is due to problems with both the float valve and the fuel petcock.

[jjktmrider]

Yet another bad petcock , they will all leaks sooner or later . The needle valves seem to be shit on these because it really shouldn't matter if the petcock leaks , the needle valve and seat should stop it , but they don't . I put 2 new ones in mine in the last couple months and still if I leave my petcock on gas will usually fill the cylinder (did it 3 times now due to forgetting to shut that petcock off , even with new needle valves. I have the vacuum line disconnected so it isn't going there.

[shuswap1]

WEDOO, Noble provided best advice, change out that very problematic O-ring, found under the seat of the float valve. It is far less likely the needle itself than the 25 cent o-ring. An awful lot of people  have changed out perfectly serviceable rubber-tipped float valve needles needlessly.

 

JJKTMRIDER, the float valve may not be the leak issue, have you located and changed the little bugger o-ring?

Edited November 7, 2015 by shuswap1

[jjktmrider]

The first time I had a complete kit and replace the seat and all , didn't leak for a while then started again , since I had another needle valve here, I put that one in but not that o-ring.  Just surprizing that of the 8 "toys" I have currently , the DRZ is the one that keeps leaking . The others just need seal replacements once in a couple years and I seldom shut any petcocks off(bad habit even if not leaking), thus why I keep forgetting to shut the DRZ's off.

I've heard of others insisting to never needing to change those valves(rubber tipped plunger) , like it's a crime , they're cheap and get hard /crappy from the gas also in time , so why not ? In the past, 95% of gas overflowing issues I've had, have been the needle valve , never really did change those o-rings underneath till a few years ago. Maybe Suzuki isn't using a good gas-proof o-ring down there.

[wedoo2]

I want to thank everybody for the responses.  Shows you have a pretty good forum here.  I am semi retired and work at an old timey motorcycle shop and the guy who owns it is older than me.  He seems to accumulate stuff more than he fixes, or sells, bikes.  Maybe around 75-80 older Hondas, other metrics and some Harleys,  Hde loves Magnas The mechanics he has had were guys he picked up and stayed for a while, started a lot of things and then left.  His choices of staff have been pretty bad and a good amount of people have taken advantage of him.  I want to help him all I can.  I have done restoration on bikes of my own for years but I have limits, and a propensity to lean on forums like this.  I won't name the shop because a lot of forums have rules against advertising.

 

Anyway, I was happy to see that this one is active.  Maybe someone here has an old Aermacchi Harley two-stroke they can help me with when I get stuck.  I disassembled the carb on the Suzuki again, put in a new float pin and replaced the seal and it's not leaking.  I read the posts about needles too late, although if I have more trouble I will change it too.  One thing, I don't think that there is an off position on the petcock.  Maybe the OEM was replaced.  Don't know for sure and the owner is clueless.  The bike seems to run strong now, especially since he pushed it in.  Good throttle response.

 

He complained of it running okay, then got hot and died.  I suspect that there is more going on, maybe valve lash, but he wanted to get the carbs straight first.  Besides they were leaking.  I have read posts about this on this particular bike, intermittant running issues when warm but theroies are numerous.  Anyone think my troubles are over?

[Noble]

" I don't think that there is an off position on the petcock".  I'm surprised you are confused by this or may I don't understand what you mean here.  The whole point of a petcock is to turn off the gas. Manual petcocks are typically marked ON, OFF, RES.  Automatic (vacuum operated) petcocks are typically marked ON, RES, PRI.  When set to ON or RES and there is no vacuum (when the motor is not running) the fuel is shut off.  So you are right, there is no marked OFF position. Gas is off automatically. Vacuum petcocks are common on carburated emissions controlled motorcycles.  Suzuki has used them since the 1960's.

[jjktmrider]

Kawasaki does also on many of it's bikes , don't know since when , my '95KLX has one that still works fine , I had a KLR and it's auto petcock also work fine as long as I could stand the bike.

 

BTW , my carb doesn't have that red diffuser or baffle that is held on by the mainjet , never seen one on any other carb I have either ????

Edited November 7, 2015 by jjktmrider

[shuswap1]

The first time I had a complete kit and replace the seat and all , didn't leak for a while then started again , since I had another needle valve here, I put that one in but not that o-ring.  Just surprizing that of the 8 "toys" I have currently , the DRZ is the one that keeps leaking . The others just need seal replacements once in a couple years and I seldom shut any petcocks off(bad habit even if not leaking), thus why I keep forgetting to shut the DRZ's off.

I've heard of others insisting to never needing to change those valves(rubber tipped plunger) , like it's a crime , they're cheap and get hard /crappy from the gas also in time , so why not ? In the past, 95% of gas overflowing issues I've had, have been the needle valve , never really did change those o-rings underneath till a few years ago. Maybe Suzuki isn't using a good gas-proof o-ring down there.

 

Well, feel free to change any part you want but my 2003 needle valve rubber tip is still sealing just fine, not hardened at all. Thinking 'ahead', I bought a replacement for about $50, 5 years ago, still sitting around somewhere. I don't call that cheap if it wasn't necessary!

[jjktmrider]

Ya, they're expensive if you buy them from Suzuki or as an oem part . This is what I get them for usually http://www.ebay.com/sch/i.html?_from=R40&_trksid=p2060353.m570.l1311.R2.TR5.TRC0.A0.H0.XMikuni+needle.TRS0&_nkw=mikuni+needle+valve&_sacat=0

 

just need to find the size needed in the DRZ. 

Edited November 7, 2015 by jjktmrider

[Noble]

jjk - the baffle on the main jet is on all DRZ400 carbs both Mikuni and Keihin.  It was natural color to start with, the discoloration is from the gasoline.  If you don't have one, it is missing.  Not a big deal, it does not do much.