paxdad Posted January 18, 2011 Report Share Posted January 18, 2011 Well as previously posted I cleaned out the carb on my 04 125 and had it idling smoothly and did a short ride with everything working just fine. Fast forward my son takes it out for a ride yesterday afternoon and drops the bike for a period of less than 15 seconds. He proceeds to pick it up give it a kick and off he goes for some backyard riding. He says the bike ran great and the idle issue fully resolved (see my previous thread). I get home and decide to start the bike to see how it was idling and it will not start. Check for spark and all is good but notice plug is wet with fuel. Kick it over numerous time to try and disperse the fuel build up etc. replace with new plug still will not start and again remove new plug test spark but still wet with fuel. Remove the head pipe to try and let fuel evaporate and head pipe is about half full of fuel!!! Muffler is also saturated with fuel. Drain transmission/ clutch oil and it is ok with no signs of fuel. I am perplexed! How could this much fuel have gotten into the exhaust and still run while son was riding it in the back yard??? If the oring on the choke jet is bad can that let a substantial amount of fuel by and over the piston into the cylinder? Could a stuck float cause this situation without the overflow showing signs of stuck floats?? Again the bike ran great after I cleaned the carb and rode it up the street the night before and according to my son it ran great while he rode it the next day. Thoughts/ comments are appreciated. Quote Link to comment Share on other sites More sharing options...
copemech Posted January 19, 2011 Report Share Posted January 19, 2011 Thoughts around this seem to point to a carb float valve that is not sealing properly due to poor seal or a bit of trash, thus the motor will get filled with fuel after shutoff, if the fuel valve on the tank is not closed while sitting. Worst case, new needle and seat for the carburator. Dellortos are not bad about sticking floats, as they work independantly, as compared to others. Yot you do want to insure the float arms are set parallel with the carb body when the carb is inverted. Quote Link to comment Share on other sites More sharing options...
tony27 Posted January 19, 2011 Report Share Posted January 19, 2011 I'd say you've hit the nail on the head there Cope, I've heard of older betas & monts draining a full tank through the engine overnight. Luckily not to the point of blowing the barrel off when kicked over Quote Link to comment Share on other sites More sharing options...
paxdad Posted January 19, 2011 Author Report Share Posted January 19, 2011 Well as previously posted I cleaned out the carb on my 04 125 and had it idling smoothly and did a short ride with everything working just fine. Fast forward my son takes it out for a ride yesterday afternoon and drops the bike for a period of less than 15 seconds. He proceeds to pick it up give it a kick and off he goes for some backyard riding. He says the bike ran great and the idle issue fully resolved (see my previous thread). I get home and decide to start the bike to see how it was idling and it will not start. Check for spark and all is good but notice plug is wet with fuel. Kick it over numerous time to try and disperse the fuel build up etc. replace with new plug still will not start and again remove new plug test spark but still wet with fuel. Remove the head pipe to try and let fuel evaporate and head pipe is about half full of fuel!!! Muffler is also saturated with fuel. Drain transmission/ clutch oil and it is ok with no signs of fuel. I am perplexed! How could this much fuel have gotten into the exhaust and still run while son was riding it in the back yard??? If the oring on the choke jet is bad can that let a substantial amount of fuel by and over the piston into the cylinder? Could a stuck float cause this situation without the overflow showing signs of stuck floats?? Again the bike ran great after I cleaned the carb and rode it up the street the night before and according to my son it ran great while he rode it the next day. Thoughts/ comments are appreciated. I am reduced to the opinion as well that the floats were stuck open. When I got home to ride the bike after my son the fuel petcock was on as he forgot to turn it off. So if the floats were stuck after it fell over and he put it back on the stand with the petcock on it could fill with fuel. I ended up turning the bike upside down and kicking it over numerous times to completly drain the crank case and any voids in the ports etc.Once inverted quite a bit of fuel drained out of the intake, spark plug hole, and exhaust port. I disassembled the carb again and everything looked fine and when I inspected/ tested the float needle and seat they are sealing. So if the floats are stuck down and the fuel petcock is on and the bike is setting on the stand level would it not overlfow out of the side vents or would it overflow into the main jet and directly into to the engine? Or if the floats were stuck down and the bike were running could it continously suck enough fuel to keep running and fill the exhaust/ engine up with unspent fuel and then when my son turned it off that it continued to fill up? Sorry to belabor this issue. I will have it back together this evening and hopefully running good again. Quote Link to comment Share on other sites More sharing options...
copemech Posted January 20, 2011 Report Share Posted January 20, 2011 Long story made short, there is no overflow tube on this carb, only bowl vents(higher up), so yes, if fuel valve does not shut off, or floats stuck, fuel will run up and out the jets and into the bore of the carb and into the motor. A carb like the Kiehin that has a overflow tube, well it is totally useless on a trials bike due to the angle of the carb. With the history of your bike, with water and mud injestion, you can bet it all came in through the intake and carb, and this can be a real bitch to totally clean and get everything working well, but sounds like you are on the right track. Small particles can be your enemy here, and you will never see them without extreme measures. Quote Link to comment Share on other sites More sharing options...
paxdad Posted January 21, 2011 Author Report Share Posted January 21, 2011 Got it back together and it seems to be back to running well. Son rode it again this evening and he it ran fine as well. So good to go. Now I can get on with changing the water pump seals. Quote Link to comment Share on other sites More sharing options...
copemech Posted January 21, 2011 Report Share Posted January 21, 2011 Got it back together and it seems to be back to running well. Son rode it again this evening and he it ran fine as well. So good to go. Now I can get on with changing the water pump seals. Good deal. Be sure the pump seals face each other and the shaft is not grooved excessivly! Cheers, Quote Link to comment Share on other sites More sharing options...
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