paul w Posted May 2, 2007 Report Share Posted May 2, 2007 i have just re-built the bottom end on a ty175 i bought as a basket case, thing is it wont run off tickover unless the choke is pulled out. i have dismantled the carb twice and i am confident that its ok. it starts first kick, ticks over, but refuses to run if i try and open the throttle, as i say, if i then pull the choke on it will rev cleanly for a few seconds untill it then chokes up. any ideas? Quote Link to comment Share on other sites More sharing options...
max1956bikes Posted May 3, 2007 Report Share Posted May 3, 2007 its sucking in air through crank seal.if just rebuilt poss seal not home properly. Quote Link to comment Share on other sites More sharing options...
kevin j Posted May 3, 2007 Report Share Posted May 3, 2007 I would revisit the carb. If crank seal, or inlet seal, the air leak would be worst at idle (tickover?) unless the idle mixture was way rich. I take it as though it dies immediately off idle. There are some transisiton holes in the cab body just around the slide, make sure they are cleared. next range is the needle and needle jet. Squirt some WD40 over the crank seal areas and see if it changes. Use a propane torch (not lit) and apply some LP gas to the carb and base gasket areas, see if it changes. Not recommended for the crank seal area as spark at points could be ugly with LP gas. Doe it die out from lean, or from rich? the 175 had an oring on the main jet to the bowl, if that leaks it goes way rich and floods out. Quote Link to comment Share on other sites More sharing options...
paul w Posted May 3, 2007 Author Report Share Posted May 3, 2007 this is doing my head in ! so far i have ; stripped the carb x5 times and blown out, its clean, all rubbers have been replaced. checked the crank oil seals, there fine. set and reset the points x3 times thats all ok. changed the plug. its a great spark. starts first kick, ticks over but you cant ride the bl**dy thing. sod it, its off back in a corner. Quote Link to comment Share on other sites More sharing options...
scottt Posted May 3, 2007 Report Share Posted May 3, 2007 Is your air filter blocked? What size jets are in the carb? What position is the needle in? How many turns out is the air screw? Quote Link to comment Share on other sites More sharing options...
paul w Posted May 3, 2007 Author Report Share Posted May 3, 2007 (edited) hi scott , thanks for the reply, here are the details. air filter clean and lightly oiled. 240 main 25 pilot. 4th from the top. one and three quarters. the only thing i have noticed it the needle has 2b1 stamped on it, this doesnt sound right to me, i will call j.k. hirsts in the morning, if that doesnt work i think i will have to pull the cases apart again Edited May 3, 2007 by paul w Quote Link to comment Share on other sites More sharing options...
scottt Posted May 3, 2007 Report Share Posted May 3, 2007 They all sound ok, you could try giving Birketts a ring on 01229 716806 he should be able to help or offer a bit more advice. Quote Link to comment Share on other sites More sharing options...
bob abell Posted May 4, 2007 Report Share Posted May 4, 2007 O-ring installed at the bottom of the needle jet thing to seal it to the carb bowl? (and allow the main jet to meter fuel, not bypass) Quote Link to comment Share on other sites More sharing options...
feetupfun Posted May 4, 2007 Report Share Posted May 4, 2007 hi scott , thanks for the reply, here are the details.air filter clean and lightly oiled. 240 main 25 pilot. 4th from the top. one and three quarters. the only thing i have noticed it the needle has 2b1 stamped on it, this doesnt sound right to me, i will call j.k. hirsts in the morning, if that doesnt work i think i will have to pull the cases apart again 1. If it idles, there is nothing wrong inside the motor so don't pull it apart again. 2. You haven't mentioned checking the fuel level in the float bowl. 3. You haven't mentioned checking that the reeds close properly. 4. Are you sure a rag or a wasp nest didn't get into the exhaust pipe while it was off? 5. Have you checked that the jet size stampings match the actual hole sizes? Quote Link to comment Share on other sites More sharing options...
paul w Posted May 4, 2007 Author Report Share Posted May 4, 2007 thanks for the replys guys. i have been informed that the needle is indeed incorrect. i have ordered a new one. if that fixes it, i will be very surprised. Quote Link to comment Share on other sites More sharing options...
andy.t Posted May 4, 2007 Report Share Posted May 4, 2007 Hi,it does sound like a carb fault,have a close look at the pilot jet and poke the hole with a thin object to see if its clear,some blockages are not obvious to the eye. Regards Andy. Quote Link to comment Share on other sites More sharing options...
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