Problems with Zama Carb
 

I just purchase a Homelite 45 cc from Harbor Freight. The engine comes with a Zama carb. When I run the engine it seem to lag going from idle to high speed when I hit the throttle hard. I have tried richening up the low speed needle and this has helped but it still seem to hesitate a little. I have a new Walboro Carb coming from Peter at Wacker engines, but I wanted to get some feedback from you guys. Am I doing somthing wrong or is the Zama carb a lemon?

RE: Problems with Zama Carb
 

Normally, a Zama runs as good as a Walbro. They are not as well documented as the
Walbros though. For that reason, the conversion guys try to use Walbros if they have a choice.

I bought a Factory reconditioned Homelite 20" Woodsman 45 cc from Cummins Tool and it had sawdust inside it too but it has run OK.

Enjoy,

Jim

RE: Problems with Zama Carb
 

Thanks for the responce you obvously read my other post under gas engines. I coul'nt believ when I took off the cover of the saw that the entire filter was covered with saw dust. The engine still runs fine though. What kind of prop are you turning on the Homelite and in what kind and weight of plane. I originally converted a Ryobi 31, but the plane I am building is probably going to weigh 15 lbs, a zirolli p-47 1/7 scale. I figured I should upgrade before findign out the Ryobi was not enough. I want this plane to move not just fly.

RE: Problems with Zama Carb
 

Don,
I have not converted mine yet. It is still a saw. It's a nice saw and I havn't built the model yet. The engine, meanwhile, has more value as a chain saw to me.

The Homelite 45 is a 20 by 8 at about 7300 rpm engine.

Enjoy,
Jim

RE: Problems with Zama Carb
 

Some times you have to adjust the low side needle just a very little different than "best idle" to get a good transision. I have noticed occasionaly I need to set the low side a tad rich from best idle on a couple of mine. By that i am talking just enough adjustment you barely see the needle move when making an adjustment. If your trying to go 1/8 to 1/4 turn at a time on adjustment there is a good chance you will never find the optimum setting. Once you start getting close go 1/16 turn or less at a time. Some are way more "touchy" than others. And remeber, when you change the low side it may/will affect your high side adjustment so it may need to be reset again. And if the engine isn't fully broken in the needed setting for best performance will probably change till it "settles" in. Breaking the engine in on a test stand can save you a lot of frustration at the field. I always do a tear down on the carb of any engine if it isn't brand new. And almost always find crap in them. One of the worst offenders is when some one used a milk jug for a gas container. Very small bits of the plastic dissolve and end up caught in the carb. Plugging up the screen. I always use a "chainsaw" type filter in the tanks of my gassers. Keeps the carb clean and also prevents it from sucking air as the tank gets low. recently ran a G62 like that on the ground in the plane and it never missed a beat till it ran completely dry.

RE: Problems with Zama Carb
 

Thanks for the advise, that just what I needed. When I got the saw I was having trouble getting it started so I pulled of both halves that have the rubber on them and soaked it in carb cleaner. After that it fire right up. I thing the low end problem is just what you talked about, I thing I was adjusting the low end to much at a time rather than in very small incraments. I still am going to get a Walbor from Peter at Wacker engines, since I also have a Ryobi ready to go, but it still has the small Carb.

Could you also let me know what kind of prop you are running on your engine?