Poor running clone out of the box

[Hutch58]

:thumbdown:

I'm new to the site and have enjoyed reading all the great advice. I just completed my second 6.5 clone conversion (with a lot of help from all of your suggestions and photos) of an otherwise stock Doodlebug. When I fired up the engine for the first time I noticed that it just didn't run as well as the engine I used on my first conversion. It's rougher running, especially at idle and seems to die more easily. It also has a bit backfire pop when decelerating from higher speeds. Can the carb on these things be adjusted? I noticed what I thought was a black mixture adjustment screw on the backside of the carb. Has anyone had this problem and if so had any luck with adjusting the carb?

 

[Hutch58]

Rough Idling problem solved

Well, after receiving no suggestions I decided to dig into this on my own. I found that the screw I was referring to was not a mixture screw (I assume these engines don't have one and are factory set) but an idle speed screw. I increased the idle speed and this helped tremendously. I also cleaned out the float bowl. There was a small amount of debris. I don't know if this made a difference but it can't hurt. It still doen't run quite as well as the first clone conversion but these engines are probably not built to quite as tight a specification as the real thing. That's OK though, my son and I had a great time messing with these things. I'd like to lower the fenders and accent with some pinstripes, etc., but that's for another day.

 

[Jleon]

I just found an idle mixture screw on my lifan 6.5. It's hidden behind a black rectangular "cap". I broke mine trying to remove the cap from an angle. The shaft appears to be thinner than un-cooked spaghetti. Now I'm screwed!

 

[Hutch58]

I'm sorry to hear that. I kind of thought that's what that was. I was tempted to mess with it but decided not to. Are you able to put it back the way it was?

 

[wolfgang123]

you mostly likely will have to drill out your jets it would be more helpful if you would describe what it is doing better other than just running rough