paynts01 Posted June 9, 2013 Report Share Posted June 9, 2013 Took my txt pro 280 out for the first time today. Bike started on 3 rd kick, rode down to the area for practice and the bike cut out. Could not get it to start after 20 - 30 kicks, took plug out and it was dry (new ngk iridium) then pulled choke up and it started but raced away on tickover, turned choke off and it struggled to tick over. Carried on and rode around but every time i backed off the gas it wanted to cut out. Not really sure what the problem is but it seems like carb starvation. 1- only start with choke (hot or cold) 2- wants to stall when backing off throttle. Have not had a delorto carb before so did not want to play with the screws until i knew what they did or which ones which. Any help appreciated. Thanks Andy Quote Link to comment Share on other sites More sharing options...
shercoben12 Posted June 9, 2013 Report Share Posted June 9, 2013 (edited) The small one on the left Is the fuel screw. This should be about 3 1/4 turns out so put it fully in first and wind it out 3 1/4 turns. The big one is your idle/tickover. If its stalling when off the revs up your idle just turn it clockwise untill the bike will just about move along in 1st with no revs and a little clutch. Turning the small screw out makes it richer in equals leaner.... -Ben Edited June 9, 2013 by shercoben12 Quote Link to comment Share on other sites More sharing options...
paynts01 Posted June 9, 2013 Author Report Share Posted June 9, 2013 Cheers ben. Will turn it out 3 1/4 turns and check tickover tomorrow. 1 Quote Link to comment Share on other sites More sharing options...
dombush Posted June 9, 2013 Report Share Posted June 9, 2013 (edited) hi If I were to guess it sounds like one of the following problems (as you suggest, all fuelling related):- Blocked pilot jet (doesn't explain the revving on choke when warm) Incorrect idle mixture screw setting as Ben says Fuel starvation, a variety of causes An air leak Normally a bike will run very rich if the choke is applied when the engine's warm, it will rev up if there's not enough fuel to match the extra air that the choke circuit provides. The only fact that intrigues me is that the bike seems to run ok when not asked to tick-over.. is this correct? If the bike also has trouble picking up as well but runs ok at medium / high revs I would suspect a blocked pilot jet. If the bike has trouble picking up and also runs very badly at other revs I suspect general fuel starvation / float height. If the bike picks-up ok and runs perfectly ok at other revs, I suspect the idle mixture screw. If the bike doesn't just die on tick-over, but revs up and down, I suspect an air leak. good luck Dom Edited June 9, 2013 by dombush Quote Link to comment Share on other sites More sharing options...
copemech Posted June 10, 2013 Report Share Posted June 10, 2013 (edited) Bout time to learn to clean a Dellorto pilot jet it sound like! Water can do this as well, see if you can catch what comes out the bowl in a clean clear vial, you may be surprised! Edited June 10, 2013 by copemech Quote Link to comment Share on other sites More sharing options...
totalshell Posted June 10, 2013 Report Share Posted June 10, 2013 could just be set not to tickover by the sounds of it.. Quote Link to comment Share on other sites More sharing options...
paynts01 Posted June 10, 2013 Author Report Share Posted June 10, 2013 Cheers guys. When i say "backed off the throttle" i mean, going down steep hills with no throttle open and it feels like its cut out, the only reason its still running is that its in gear and the back wheel still turning, dip the clutch and give it some revs when you reach the bottom and it picks up but as soon as you back off and go back to tickover it cuts out. going up steep climbs it pulls like a train, its just when no throttle is being used. Just got home from work and going to have a look at all the above starting with simples first, Fuel air screw and tickover. Wont really be able to post my findings until i go out on it again and get up to full operating temp. Thanks again guys it is appreciated. Andy Quote Link to comment Share on other sites More sharing options...
tltel Posted June 10, 2013 Report Share Posted June 10, 2013 Normally a bike will run very rich if the choke is applied when the engine's warm, it will rev up if there's not enough fuel to match the extra air that the choke circuit provides. Dom Am I reading that right?? TLTEL 1 Quote Link to comment Share on other sites More sharing options...
dombush Posted June 10, 2013 Report Share Posted June 10, 2013 The context was the bike revving up when the choke was applied when the engine was warm. Normally if the choke is applied when it isnt needed it will cause the engine to run very rich and therefore reduce revs. If the engine revs up instead its indicating something might be wrong. The basis of this is:- The choke plunger opens a seperate bypass air venturi that draws up extra fuel from the float bowl. If there isnt enough fuel to feed this circuit the engine will see the extra air without the fuel and will therefore behave as if there was an air leak (which technically there is). As with any other small air leak the engine will rev up and run slightly weak. Quote Link to comment Share on other sites More sharing options...
tltel Posted June 11, 2013 Report Share Posted June 11, 2013 ok Dom. Read it again without the wine lubrication and I can see where your coming from. I could'nt get my head round the choke circuit providing extra air. TLTEL Quote Link to comment Share on other sites More sharing options...
dombush Posted June 11, 2013 Report Share Posted June 11, 2013 :icon_salut: anyway what we need to know is Paynts (my mind keeps reading that as something else) has solved his problem. Dom Quote Link to comment Share on other sites More sharing options...
paynts01 Posted June 12, 2013 Author Report Share Posted June 12, 2013 OK here goes. Before i took the carb off i checked a few things. Whilst bike running on tickover i sprayed carb cleaner around the plastic boots either side of carb, this raised the revs so i now know i have a air leak especially air filter side. I then checked air / fuel screw (small one on left hand side) and it was 3 1/4 turn out so put that on 3 1/2. Have now taken the carb off and noticed a small amount of miky liquid in float bowl (maybe water from cleaning as im anal about having a clean bike). Going to blow the jets out next and give it all a good soaking in carb cleaner before drying out with can of air. Also cleaned and lubed air filter ready to go. Will be the weekend before i can do anymore with working night shifts. Cheers paynts Quote Link to comment Share on other sites More sharing options...
sting32 Posted June 17, 2013 Report Share Posted June 17, 2013 (edited) If you are ANAL, and use high pressure washers, you have to learn where NOT to point the sprayer, that is for sure, I would list 3 that I never do!@ Never aim full pressure at radiators, bends fins closed easily Never aim at rear linkage or wheel bearingings directly, unless you are about to disassemble and regrease said items, water in any of those will rust the bearings. Lastly, careful around carbs and airbox. now would be a good time to take off the seat/airbox and familiarize yourself with it, the opening of the airbox is where the tank meets seat, so spraying carb cleaner could be sucked into the "normal intake loop" increasing the idle... there is a "drain flap" on the bottom of airbox to let water and vibrate some dirt out.. this sometimes deforms with dirt caught, to where it stays open and again if you get carb cleaner near it, it can cause reves to change. Milky stuff sounds like water to me. adjust the "revs" with the bike in gear, holding clutch. clutches drag on GG, so getting idle up while in gear will mean more idle speed when out of gear, which is NORMAL in today's riding, since you should have a finger on clutch and slip the clutch more to go slow if you need to. we no longer ride with the clutch 'let go' anymore, just FYI. Floats should be level (the little bar that rests on the floats little tabs) when carb is off, and upside down on bench, you may also want to check that the float has NOT got gas seeping into the little plastic floats, by shaking them as soon as you can, after taking carb apart the gas will evaporate and you will miss it. check them like you check to see if your beer is empty, well, least I do before I bring a can to my lips, lol... Edited June 17, 2013 by sting32 Quote Link to comment Share on other sites More sharing options...
paynts01 Posted June 24, 2013 Author Report Share Posted June 24, 2013 Hi Guys, Been out on the bike tonight for the first time since stripping the carb and rebuilding it. All seemed well for 10 mins and then the same old problems came back. Evertime you let the gas off it stalls, the revs drop instantly and it cuts out. Try kicking it over and nothing, pull the choke up and it starts straight away but revs to high to ride like that. Turned the tickover up a little 1/4 turn and it seemed a little better but felt lumpy on over run (down hills with no gas). Also with the tickover up the bike was not controlable, with the clutch in it kept pulling / going. This became to scary to ride like. Noticed in the oil window that the oil looked frothy ? also when you pulled the clutch in you could here a strange rattling noise from engine, but only with clutch in. Had to give up in the end as it was to dangerous to ride with no clutch. Seems like i have another problem to deal with now which is disappointing as im enjoying riding the bike for the first 10 mins before the problems start. Cheers paynts Quote Link to comment Share on other sites More sharing options...
nigel dabster Posted June 25, 2013 Report Share Posted June 25, 2013 Calm down fella, I think there is less going on here than you think! Clutch rattle is normal even on new bikes so dont worry about the noise, its fine, lets park that. The carb if its a dellorto means the bike isnt "new"? Do you mean new to you? What did you do to cure the air leak issue you noted above? If the tickover is too fast slow it right down till it just stops then A LITTLE above that is fine. Note here if it wont tickover unless its quite fast then there is something fundamentally wrong. When you cleaned the carb did you check the banjo filter? Does the choke seat nicely and make a good seal? Are the floats set at 18.5mm? All this talk of 3 or 3 1/2 turns is rubbish you need to start here and adjust to suit the particular bike/atmospheric conditions. (that said dellortos are pretty good and dont vary as much as kehins) Quote Link to comment Share on other sites More sharing options...
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