Hello everybody,
Last weekend I decided it was time to bring back to life an engine I had bought a long time ago; a Homelite 30cc (has a big carb and homemade muffler, but everything else is stock, as far as I know). I shelved it for several reasons, without even giving it a run. So I put fresh fuel on the tank, installed a cone (so I could ease the start by using my drill instead of a stick) and gave it a try.



The tank was at almost at the same level of the carb, and the tubes lines were direct. The fuel could get to the carb without restrictions. I had opened the carb and it looked like new. To make sure the ignition was OK, I unscrewed the plug (almost new) and made it spark outside of the engine. With the stick it required a strong hit to make a nice spark, but with the drill it worked very clearly. Deep Purple’s “Space Truckin’” (made in Japan version, obviously) was roaring from the speakers on the other side of the workshop. The clouds gathered to create a rain storm, and the wind whistled while dancing with the leaves. The situation seemed just ideal to make an engine fire up.
Yet, after many random explosions, the best I could get was a few seconds of noise at a about 10-15% top rpm with the starter an butterfly closed, after priming it and giving it a good spin. High and Low needles started at 1-1.5 turns, but I changed that to see if it improved anything (it didn’t). Definitely, something was wrong, but I had other stuff to do so I decided to work later on it.
After thinking of it, I believe I found the main reasons why it didn’t work properly.
First, and I’m almost ashamed to say this, after looking at several pics of similar carbs, I believe I reversed the pulse and fuel connections; I connected the tank (blue line) to the pressure port and plugged the fuel intake (green cross). I wasn’t sure which was the right port, so I looked carefully and saw that priming the engine trough the current port (blue line) would make the carb pour the fuel through the small holes on the venturi. I guess I was wrong… I just hope I didn’t break or bend anything (should I check the needle valve lever height in the carb, perhaps?).



Second, I don’t see any pressure lines going to the carb, so it can pump the fuel to the engine. Perhaps such connection is done through the carb spacer, I don’t recall if my engine worked that way (I’ll check when I get to my workshop).
There’s a hole indeed, I don’t know for which reason (perhaps to make staring easier?), in the middle of the block. I plan to close it with a headless screw and some glue to fill the gaps, unless I hear of a better idea.



My theory is that the engine ran shortly on the primed fuel, as it wasn’t able to get enough (if any) fuel to keep running - because of the possible lack of pumping and wrong fuel piping. But even then, shouldn’t a primed engine start effortlessly?
Just to make sure I’m pointing in the right direction,
[ul][*] I have to reverse the piping connections.[*] I should use a high temp rated epoxy to install the nipple, and plug the hole.[*] If there’s no pulse port throught the carb spacer, I’ll have to drill a hole in the crankcase, epoxy a nipple to it and connect that to the carb (as you see in the pic). By the way, is there a preferred place to make that hole?
[/ul]




I would like to try a few things on this engine, as it’s my first gasser, but I must make sure it works flawlessly first, so any help will be welcome. [&:]
Have fun!