1980 YAMAHA 175 dt-barely starts HELP ME!!!!!!?

Question

I have a Yamaha 175 dt. I kick the living **** out of it, and it's started two or three times. And it dies right away unless you leave the choke out. I replaced the spark plug, fuel filter, took the carb off and sprayed a whole bottle of carb cleaner through it, and cleaned the air filter. It has spark and im pretty sure it's getting gas, but it still wont start consistantly. And if it does, it wont stay running for long. I just took the exhaust off to see if that's the problem, and tryed starting it for about 5 min., but my leg felt like rubber so I came in to type this and take a break. PLEASE HELP ME!!!!!!!!!!

Answer 1

Probable clogged pilot jet in the carb.

Remove the pilot jet and hold it up to the light - you should be able to see through it (the main jet is in the center, the pilot jet is off to the side).

While the carb is off, remove the reed block and hold the reed valves up to the light - they should firmly seal with no air gaps.

Answer 2

here ya go http://www.bikebandit.com/houseofmotorcy... then click on the various diagrams to show exploded views of all the main components.

those little carbs are pretty simple to work on and take apart.  pay close attention while dissassembling to insure you get it put back together correctly.  I would also suggest getting a shop manual for it too.  tearing into the carb and thoroughly cleaning all the parts with an old toothbrush & carb cleaner is your best bet.

other issues could be low on compression, needing a new top end which is entirely possible since it is a 28 year old bike.  

another very likely problem is the muffler packing is saturated with unburned 2 stroke oil causing excessive back pressure not allowing it to run properly.  there should be a s***w at the tail end of the muffler that can be removed to pull the endcap out of the muffler.  this end cap should have a packing material tightly wrapped around the baffle pipe that sticks into the back end inside of the muffler.  this packing can be removed and new packing material applied.  relatively easy to do and inexpensive.

more than likely one of these three things is what is causing your problems.

Answer 3

How long has the bike been sitting ? Does the engine seem to have good compression when you kick start it ? Two stroke engine have a tendency to have the crankshaft seals dry up in time. when that happens the engines don't build enough pressure to push the gas up through the ports to run very well.

    I would actually take the carb apart and clean the jets, taking close attention to the pilot jet.