I think I found the worst dr350 carb EVER - Help!

Discussion in 'Thumpers' started by big-guy-little-bike, Jul 19, 2013.

  1. big-guy-little-bike

    big-guy-little-bike Adventurer

    Sep 24, 2012
    Ok I should preface this by saying I have rebuilt carbs in the past with good results - But my 97 dr 350se carb is beyond me-

    Here is what it WAS doing-
    when I rode flat out or over a hill it would start to spit and sputter like it was running out of fuel. If I let it sit a minute it would start and run fine unless I gassed it hard again (I have a translucent tank so I knew I had fuel) so I figured the float bowl was going empty too fast for some reason and it would clear up if I cleaned the carb.

    Not wanting to tear it apart just yet I dosed the gas with Seafoam first to see if that would clear it out- it helped but did not clear it up completely so I decided to clean the carb- big mistake

    Ok so I took it apart completely and cleaned everything, set the float to where it was supposed to be using a caliper (around 14mm) and I set the mixture screw to around two turns out - It started ran like a champ for 10 seconds then started loading up and bogging out and missing, shit!

    So went to the forum boards and everyone said to make sure to replace the o-rings for the needle seat and the plastic cage that holds the float, and make sure the slow jet was clean and seated well - shit that didn't work.

    did some more reading and got to thinking maybe the guy who sold it to me put a larger jet in it for a pipe and never swapped it when he put the stock one back on and sold it to me - I bought 127.5, 135, and 137.5 main jets so I could put the stock 127.5 in and maybe get a pipe later for the others- nope that didn't work

    when it would run I noticed it developed an exhaust leak so I decided to try putting an aftermarket pipe on thinking maybe that had something to do with it- tried it with all three main jets- no dice

    Checked my petcock to make sure it was good - it was,
    Checked the plug on the frame to make sure I was getting spark- I was

    I am out of ideas and thinking it is something simple I am overlooking
    Does anybody out there in ADVrider world have an idea what is going on with my poor suzuki? any help would be much appreciated!!!!!
  2. fossriver

    fossriver Adventurer

    Aug 25, 2010
    The convergence zone
    Making a diagnosis over the internets is not my specialty. But, if You want a perfectly good cv carb off a 99 SE for cheap Pm me.
  3. PistonPants

    PistonPants Crankcase Scavenger

    Jun 11, 2008
    Cantwell, AK
    The vent tubes that supply atmospheric pressure to the float bowl could be plugged. If they are kinked or plugged it could cause these symptoms. I've seen kinked ones, plugged with mud and insects, iced up.

    Good luck
  4. big-guy-little-bike

    big-guy-little-bike Adventurer

    Sep 24, 2012
    That sounds promising- is that the vent that has a tube connected on the right hand side? if so I have tried that- if not I would like to know where it is so I can check - Thanks!
  5. Kawidad

    Kawidad Long timer

    Jul 9, 2005
    Central Coast, Cal
    Not trying to be a jerk, but your descriptions seem a little vague and all over the map and your diagnostics are inconsistent.:d

    An exhaust leak just doesn't happen and won't do anything like you're describing, plus changing pipes in the middle of trying to diagnose a carb problem will only worsen the problem. You need to limit your variables, not increase them. You also need to be systematic and figure out exactly where your problem arises, like idle, or WOT, etc.

    Your original problem sounds like fuel starvation at high rpm's, but after cleaning you said it ran good for 10 secs then it loaded up and bogged out. Loading up suggests too much fuel and bogging could also mean too little fuel or too much.

    Did it start and idle without touching the throttle? Or is it acting up when you twist the go handle? And, at what point of the rpm scale does it start acting up?

    You said you checked the petcock, but did you pull it and check the filter screen?

    You suggest you replaced carb parts after reading suggestions on the internet, but did you? Did you use OEM parts or an aftermarket rebuild kit (which can be utter crap)?

    Anyway, I'm sure people here, including me in my limited fashion will be more than happy to make suggestions, but if you refine your troubleshooting and descriptions the advice might be better.

    FWIW, it sounds like your original problem could have been a partially clogged petcock filter or main jet, but after tearing into the carb and replacing parts and re-setting the float height, something else got messed up.

    HTH :wave