Need a little help here.

I have a brand new 46gt with about 16oz of gas (32:1 penzoil) through it. It was lean coming from Scott and that was adjusted. The top end is not the issue( at least I don't think). The problem is the low-end. There is a lot of un-burnt fuel coming off the carb. When I let it idle for a while and throttle up, it tends to die every now and then. Thinking it being too rich, I leaned it, No difference. So I richen it. Still no difference. When I tached the low end to see whether it was speeding up or bogging down, it seemed to be holding steady @1700rpm. Now I am at a little loss....

BTW, my other 46gt is running well. Just not sure what is with this particular one. Any help will be appreciated.

Azhar

I'd swap carbs if you are lucky enough to have two of the same and see what you get. In doing so will help you sort out whether or not it is a carb issue or mixture issue. I assume compression feels good?
Good luck, you'll sort it out and I know Scott will be there if you need him.

Maybe you didn't lean it enough? If it idles for a long time fuel will build and it will die once you throttle up quickly. In this case the idle should slowly get lower, and eventually die. If it idles for a long time and the idle slowly gets higher it's too lean. It may hesitate (bog) or even die if it's throttled up quickly in this case. I'd tune it so the idle stays the same RPM for a long period of time....30 seconds for example. Also listen to the midrange. You can hear a 4-stroking sound...sort of a missing of the firing. If it does this keep leaning until you hear a smooth continuous sound throught the entire midrange (except for near idle, usually some 4-stroking has to stay there for a quick transition). Then test the transition. You want the 4-stroking almost gone...but you always want a little there at the bottom. Make sure it snaps up to full RPM's as quickly as possible. If this tuning doesn't help, you have a bad carb IMO.

Just curious what prop you are running?

Joe,

I am going to try and lean out the low end and see what happens. It must explain the high amount of unburnt fuel coming off the carb. The prop is a JXF 21x8. I might try and use the 20x8 that I have lying around.

Azhar

Azhar,
It does sound like it could be a little rich on the low. The best way to do the low is keep leaning it until it won't transition. Then richen it enough to get transition back. Do all adjusting once it is good and warmed up. The thing is, if it is a little too lean it will do the same thing, so that is why I say to lean it until it won't transition. That way you found the point of being too lean and have somewere to work from.

Scott,

Thanks for chiming in. Hope you are feeling better. Right now the low end is over 2 turns open. I am going to lean it and do as you suggest. Will let you know at the end of the day or tomorrow.

Azhar

at that far out you are def way rich...

Jake,

You are right. I was confused for a while but I think I have it dialed. We will see in the next day or so when I get it up.

Azhar