I have converted a Homelite 33cc chainsaw engine and I went to start it. I tried hand starting it and it wouldn't fire. I remove the spark plug to see if I was getting a spark and I wasn't getting one. I adjusted the distance of the magneto to the flywheel and I finally got a spark. I tried to start it again and nothing. I then checked again, the spark with the spark plug removed and found that I have to really spin the prop very fast to get a spark and it doesn't always spark. I have converted a Homelite 30cc weedwacker engine and it starts really easily and sparks without having to swing the prop so hard. I have also converted a Green Machine 7700 chainsaw, (Zenoah G-62) engine and I can hand start that engine too. My question is, do I have a bad magneto? or does the 33cc engine always have this problem? My next question is, can I swap the magneto from the 30cc engine to the 33cc engine? They look very similar. My next question is, has anyone converted the Homelite 33cc engine to a different ignition system and has the old magneto laying around? I may need one. Any suggestions would be appreciated. Thanks

Paul

Paul,

I found the same thing. I have converted both types of engines and the 25/30cc types out of blowers/wackers start a lot easier than the 33s out of chainsaws. The 33s require a much sharper flip but they do hand start. Try experimenting with prop postions: 12 o'clock, 12:30, 1 o'clock, etc. Also try using 50:1 oil if you're not already, that seems to make them easier to start.

The only reason I can figure for the chainsaw engines requiring a faster flip is for safety reasons, but that's just a guess. I thought of swapping mags with on of the 25s but the magnets are different.

rsjr started a thread here somewhere about the 33cc engine and he uses a portable drill as a starter.

Jim

Jim

Thanks for the input. I went and looked at the magneto for my Homelite 30cc and saw that the coil and the metal contact points are larger than my 33cc engine. So what you said made sense. I still tried to see if I could get the 300cc magneto on my 33cc engine. I think it might make it but you have to enlarge the mounting holes and I'm not so sure I want to risk messing up a good magneto. My 30cc engine runs good, but it's heavy. I wanted something small but more powerful so I go a 33cc engine. Now if I can only get it to start! I don't want to use a starter on these gas engines. The reason why I thought they are so good is that you don't have to hook up glow starters, use electric starters etc to get them to start. You just have to give them a few flips and they start. That is when you have them set up right. I'll try changing the prop location. I have it set up the way I have always been setting them up on my other engines. If anyone else has any comments on the magneto ignition for a homelite 33cc engine, I'd love to hear about it. Thanks

Paul

Hi,

Any way to wrap a pull start rope around the prop adapter hub??

Just a thought,
AV8TOR

I finally decided to try my electric starter and the engine started, but it wouldn't run. I backed out the needle valves and it still didn't run. I finally got it to run by holding my finger over air intake, choking the engine. I think i have an air leak and that is causing the pump not to work on the carb. I have a stupid question, but since I got the saw in pieces I never saw which tube on the carb is the feed tube and which is the vent tube? Can anyone tell me? Right now I have the feed line hooked to the smaller tube located in the middle of the carb and the vent line to the larger tube that is closer to the top of the carb. Is that correct? Any help is appreciated. Thanks

Paul

Put the feed tube onto the bigger tube on the carb, and block off the narrower tube. I usually pinch it off and sweat solder it closed to seal it. You could also put on a short piece of tubing and plug it.

If you got the needles out of whack now, just set them at 1-1/4 to 1-1/2 turns out and start from there.

Here's a picture of how mine is set up.

Jim

Jim

Thanks for the picture. I definitely had the feed line on the wrong tube. But I tried running it again today and it didn't run any better. I switched the tubes and tried choking the engine and it didn't suck any fuel when the line was hooked to thelarger tube. It seemed to be sucking through the smaller tube which I had hooked to the vent line back to the tank. When I hook the feed line to the middle smaller tube the engine sucks fuel easily when fully choked. I also noticed that your carb is mount upside down compared to mine? I have the needle valves facing forward. I checked the carb mounting piece and and the hole from the engine that drives the pump is lines up correctly and the carb's pump hole is lined up on the mounting piece. I'm confused? Of course if I didn't have the pump hole lined up correctly that would explain why the engine is not running right. Have you ever seen the carb mounted with the needles pointing forward? Thanks for your help.

Paul

Paul,

The engine will run with the carb either way. I turned it around for the plane I'm using it in. I don't understand why it won't draw fuel through the tube for you. If you removed the choke did you plug the holes where the choke shaft was? I forgot to do that once and couldn't understand why it wouldn't draw fuel when I choked it with my finger.[sm=bananahead.gif]

It seems a though grate minds do think alike..... LOL!

The engine will run with the carb either way. I turned it around for the plane I'm using it in. I don't understand why it won't draw fuel through the tube for you. If you removed the choke did you plug the holes where the choke shaft was? I forgot to do that once and couldn't understand why it wouldn't draw fuel when I choked it with my finger.

I might be mistaking but if you turn your carburetor around the vent line that 'flick' the pump won't align and it won't draw a fuel.Correct me if i am wrong