I took apart the carb again, the fuel bowl retaining nut's fuel hole(has only one hole) was clogged.. i cleaned that, was able to blow air through it. I expected it to work but still nothing. Same thing. started with a little starter fluid and died 10 seconds later. Is it safe to say that if it starts at all, it's not spark?
Bought a used mini bike with H35 engine. Won't start, what to try 1st?
I'm not a certified small engine mechanic, but all engines need 3 basic things which are AIR, SPARK and FUEL.
Putting these into your situation:
AIR- Should not be a problem. Take off the air filter if you suspect lack of air, but I doubt it.
SPARK- If you're getting spark with the previously described "spark check" or if the engine fires up with the use of "starter fluid", spark is not the problem.
FUEL- Use the Drain to see if there is fuel getting in the "fuel bowl". If you are getting fuel in the "fuel bowl" you're doing good so far. If there's no fuel in the "fuel bowl" clear out or replace the fuel line from the tank to the carburetor. If you have cleaned out the carburetor and ensured fuel is getting through the carburetor to the combustion chamber (cylinder) and it still won't start then I would next suspect the carburetor adjustment settings.
Follow these instructions to get initial settings to get the engine going first and then make final adjustments. I hope all of this helps to get your engine running.
Putting these into your situation:
AIR- Should not be a problem. Take off the air filter if you suspect lack of air, but I doubt it.
SPARK- If you're getting spark with the previously described "spark check" or if the engine fires up with the use of "starter fluid", spark is not the problem.
FUEL- Use the Drain to see if there is fuel getting in the "fuel bowl". If you are getting fuel in the "fuel bowl" you're doing good so far. If there's no fuel in the "fuel bowl" clear out or replace the fuel line from the tank to the carburetor. If you have cleaned out the carburetor and ensured fuel is getting through the carburetor to the combustion chamber (cylinder) and it still won't start then I would next suspect the carburetor adjustment settings.
Follow these instructions to get initial settings to get the engine going first and then make final adjustments. I hope all of this helps to get your engine running.
I had the same problem with my 5hp Tecumseh, it would only stay on for about 5 seconds. I took the carb apart, cleaned and reinstalled...still had the same problem. Try this, (it worked for me)...Dip your carb in carburetor/parts cleaner for about one hour...let dry or shoot air with air compressor in all holes of carb (careful not to get carb solution in eyes/face) reinstall carb and that should do the trick. A guy at the minibike shop taught me this. My 5hp Tecumseh runs like a champ now. 
