I am having problems with the bellcrank setup on my US41. The throttle transition is not linear with the travel on my transmiter. I have tried changing the position of the clevises on the belcrank and on the servo and still am not happy with the setup. I am having trouble with the idle. One click up on the trim: too fast. One click down: it dies. I was wondering if anyone knew of a carb mounting block that would rotate the carb 90 degrees alowing for a straight shot to the throttle. If one isn't available comercially, how hard would it be to make one up myself. I bet this is a job for RCIGN!! I'll get in contact with him if no comercial unit available. On my 25 cc homelite, there is a premade unit available for purchase that rotates the carb, and I know that Zenoah just came out with something alike.....how about for the US41?

I have a carb mount for the US 41 that has the half air grove cut out towards the fly wheel.
Carb mounting holes are 2 o`clock & 8 o`clock and it has the two lugs on the back of the mount.
It is new and it should be what your looking for.
Here are a couple of pics of it, if you can use it send me a email at the link below.

pic#2

pic#3

Wayne

I can suggest that Raplh can and will make a custom carb adapter as you mention that will rotate the carb to any position you desire...

Are you using a programmable radio? If so take a look at the throttle curve. The problem you describe is pretty common in that the transition is non linear with most gassers. I typically have to tailor a throttle curve for most of my gasser's to achieve a balanced linear transition...

Your carb needles may also need attention.

Is your servo arm and bellcrank arm pivot the same length? Is your servo centered when the carb is open half way or centered? Both of these items will effect the ratio or geometry of the linkage and cause some problems unequal movement...

Thanks Cub 1 for trying to help. The unit that you have is the very same one that I have. This is the stock carb mount which will put the throttle arm in a vertical position. I am trying to rotate the carb 90 degrees to have the throttle arm in a horizontal position. Thanks for replying. I have been messing around in the shop and have found some 3/8 inch thick aluminum plate that I think I will try tooling to see if I could make one up myself. I am not sure if it would work though because I have read that the aluminum block will transfer engine heat to the carb and vaporize the fuel (not a good thing). How about some thick gasket material between the engine and carb mounting block? Well I still have to make the thing first. I'll post a picture of my attempt to make a 90 degree carb rotating block as soon as I finish it. Anyone out there know of one that I can purchase. I wonder if the Zenoah part would work. I have a homelite carb rotater here somewhere...I'll have to look..if I remember right it is called a "heat dam". Thanks for your help.

MGlavin thanks for the help. No computer radio here, just a basic 6 channel. I have already checked and tried the things that you mentioned. I found that the problem was in the arm between the bellcrank and the carb. The manufacturer use some type of ball link that would allow a little bit of slop. The vibration of a the engine would not allow the bellcrank and throttle arm to hold a steady idle..it is not a firm connection. I will work out a straight shot to the carb that will hopefully correct this. Does anyone else that has a US41 have this problem?

Wayne,
You can try putting two bellcranks together to cut out the vibration and the flexing.
B&B sells this item or if you have a extra bellcrank laying around you can make it yourself.

Wayne

As I mentioned Ralph or RCIGN can and will make what your looking for, $15.00 out of g-10 fiberglass.

I would stay away from the metal adaptors. Plastic, Teflon, Phenolic, Resin cast, fiberglass or even Durlon will work well, insulating the carb from heat migration is desired...

I suspect the Zenoah G45 adaptor will work...

I did the double bellcranks on the Poulan 30 in my Edge this past weekend, works great.