Quantcast
Jump to content

Recommended Posts

Posted

ok ok, it's not a quad, it's a kids bike, but it's still an issue I need solved lol. so with the choke on, it fires up first kick, but as soon as you take off the choke it dies. I removed the carb and sprayed it down with wd40, no help, maybe I need to actually soak it in a carb cleaner bucket for a night...I'm assuming it's a carb problem, but dunno? this carb is a little differant than the big quads i'm used to, it has some...apparatus lol...next to it with a very small air, fuel, or vacuum hose, not sure which, connecting it to the carb? anybody know what i'm dealing with here? I've never dealt with these little guys so don't know a lick about em... thanks in advance

Ryan

Posted

From the sounds of it your not getting enough fuel with choke off. So I personally would do a carb clean and check your jets and needle. Also if you can take a pic of the piece your talking about it would help out for people to see what your actually talking about and might be able to give you better advise. Quick question are you letting the bike warm up properly before shutting the choke off? I know my sons ttr90 has to warm up to running temp before I shut the choke off and then it runs perfect.

Posted

ill do that then. I do let it warm up, let it warm up for about 10 minutes the other day on a 70 degree day (saturday) just to make sure that wasnt the issue. im going to pull off the carb again tonight and soak it overnight, ill take some pics of the "apparatus" lol and post them, thanks guys.

Posted

so heres some pics, the first one is of the carb, the other three are of the "apparatus", it looks attached to the crankcase, let me know what ya think...

IMAG0491.jpg

IMAG0490.jpg

this last one is of the carb removed and the hose that connects to the carb...

IMAG0492.jpg

Posted

So I'm stumped. I had the carb in the carb cleaner can for 24 hours soaking, pulled it out tonight after work, pulled the idle and primary jet off and sprayed the crap out of them and their respective holes, and just for good measure, sprayed the crap out of every orifice I could find on it, put it all back together, and nothing changed, still idles great on choke, and dies off of choke... I'm at a loss for words :(

Posted

You may have the carb as clean as it's going to get and just need richer jetting :unsure: Even though it sounds more like a blockage somewhere in the idle circuit, it would be a shame to overlook an obvious solution, right?

Posted

so you think adjusting the jetting out some would possibly do it, im no carb professional, so try to speak about it as if you were training a 10 year old and ill probably understand lol.

Posted (edited)
so you think adjusting the jetting out some would possibly do it, im no carb professional, so try to speak about it as if you were training a 10 year old and ill probably understand lol.

Right on man. Carbs are simple in principle…but can be complicated in execution ha ha ha. When you put the choke "ON", what you're doing is opening up an additional circuit through which fuel can flow. This gives the engine the additional fuel it needs for combustion to occur at lower temperatures. A properly jetted engine should have a hard time burning all the fuel it sucks in with choke on after it’s warmed up.

In your case it sounds like there isn’t enough fuel getting through to the combustion chamber without the utilization of an open choke circuit. That likely means that the idle circuit (the gas flowing through the pilot jet AND through the gap between the main jet and the needle in it) is insufficient. A larger main jet will put more room between its inside diameter and outside diameter of the needle, which is one way to increase the flow of fuel at idle. Increasing the pilot jet is another. Or there could be an unnatural blockage like sand, etc wadded up in the either of the jets or around the needle that is reducing the flow.

Edited by Senator
Posted (edited)

awesome write up man, thanks, I adjusted the jet about one turn and vio la, no more problems! on my way out the door to head to sandlake, or to camp at the dunes, thanks man.

Ryan

Edited by the_ry_guy
  • 1 year later...
Posted

same problem, took carb apart cleaned everything ,crnked right up, wide open with choke on, turn choke off.....dead. going by local shop will let you know. coachj

Posted

make sure when you put carb back on that you line up the Throttle Vaulve. ther are 2 slots 1 long and 1 short on the vaulve. look down inside the carb you will see a small pin on each side 1 high and 1 near the bottom align the slots accordingly( long slot high pin) let me know if this helps... coaachj

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Similar Forum Topics

    • By P_syko
      I’m brand new to 4 wheelers and just bought a 1987 Yamaha Moto 4 350. It has good compression and fuel, but no spark. I’ve looked high and low trying to find how to test all the components of the ignition system, but can’t find anything. This has a new CDI box on it, but I suspect it might be the stator. How do I test the stator on this? Any help would be greatly appreciated! 
    • By DPDISXR4Ti
      I hadn't driven my Kodiak for a two months, and since it was low on fuel, the first thing I did was filled it up to maybe 7/8 full. Getting ready to start it, I rotated the fuel selector switch to "on" and within seconds I smelled and saw fuel dripping onto the floor. I quickly turned it off and the fuel gradually stopped - I can repeat this.
      The fuel is flowing from the hose that is connected to the bottom of the carb, and routes around to the left side toward the wheel well. Any idea what's going on here? It ran fine the last time I had it out.
      Thanks...
    • By carkivey3
      i just picked this up. was told ran fine but overheating issues led to replacing head gasket and head. has not ran since. he is not a mechanic but helped someone else who he could not get back to finish job, got aggravated and put up for sale. i was thinking timing issues. i have 110-120psi on all 3 cylinders so i think valves are correct. dont know about distributor yet. however i have no spark. i have no power going to ignition coil. tried to follow white wire but gets lost in wire harness. does anyone have a wiring diagram? can anyone tell me what conditions have to be met before starting. motor turns over so i would think all safeties are met but you never know.
    • By jhamrick75
      If anyone is having issues with the Mikuni VM24SS carb, I thought I would post what issues I had and how I resolved them.
      Acquired a 93 Bayou 220 that had sat for over 4 years.
      The carb was extremely corroded and pitted and full of leftover fuel.
      Cleaned carb and bowl and was able to get the engine to start.
      Within 30 seconds exhaust would heat up and start to glow red hot.
      Removed carb and recleaned everything, including a second overnight soak.
      Needless to say, after removing the carb for the 5th time and my frustration to the limit I
      realized that my attention had been to the carb body and not to the bowl.
      There is a small brass rod on the bottom of the carb that goes down into the float bowl but is seperated from the main section. I had cleaned that area very well....I had thought.
      ***The corrosion had sealed off the channel that runs from the main bowl section to the small tube section on the side of the float bowl. No amount of carb cleaner was going to get it to budge. So i took a small nail and started to scrape away the corrosion and was eventually able to dislodge enought of the corrosion that carb cleaner would flow through that channel. ***
      I thoroughly cleaned each side of the channel in the float bowl and reinstalled the carb and now the issue of it running lean is gone.
      On a second note the fuel mixture screw was a nightmare to remove as the threads had been corroded and wouldnt let the screw come out. I used a little cutting oil and worked the mixture screw in and out until I was able to push past the corroded threads and completely remove the needle. After a couple passes with a tap to clean the threads it is like new again.
      Hope this helps if you are having a lean running machine.
    • By Ethan7387
      Hi could someone please help me, not to sure what engine this is 


×
×
  • Create New...