Tank position, help needed

[Paul De Tourtoulon]

"If" you could find a bit of metal tubing to fit into the carb then you could always fiddle about with a silicone tube as an extension if only to see if it works, of course 'on the ground',,

 

I have done a bit of this type of tinkering on my Enya 120 4C with success, the length of the extension can radically change the way that the engine runs.

[Denis Watkins]

1 hour ago, Engine Doctor said:

Below is a sketch drawing to give the idea of the carb extension for OS and copies of type engines. Measurements will obviously have to be adjusted for different sizes of engines. Sorry for pic orientation. tried to rotate but keeps coming up sideways but gives the idea. When I made mine I also incorperated an "O" ring in the top of the extension tube.

 

 

[Engine Doctor]

Hi Jon . No chance of it being widely adopted these days as few seem prepared to invest any time and effort to making and fitting the conversion 

The machining is simple and "o" rings seal any minor imperfections. On my effort I used a piece of Tufnol for the extention tube thst was a tight fit onto the manifold with no "o" ring.

As for negative effect on the engine performance it may have lost a couple of hundred rpm at top end but idle and reliability was excellent. 

 

Back in the 1960's a work mate rebuilt his Triumph Bonneville. He mounted the carbs on the frame with hard rubber hoses after reading about it in a magazine.

The article said it would increase performance . His Bonneville had tremendously increased torque after the conversion and outrun any of the local competition. 

The downside was that it was dangerous to ride in the wet due to the torque spinning the wheel at the slightest provocation. The explanation at the time was that the increased inlet tracts allowed complete vaporisation and mixing of the incoming charge and kept the carbs cool ?

[Jeffrey Cottrell 2]

Hi Guys

Apologies, I haven't posted for a while. Believe it or not, I've been thinking.

When I first questioned the tank height I was measuring it from the carb to the centre line of the tank.
The diagram Jon posted shows the carb level with the top of the tank, when full. Logical, I suppose, but in this case makes things even worse.
So, I've come to the conclusion that this motor and model do not go together.
Much appreciate all the ideas you guys have come up with, especially the chicken hopper tank and the carb tube extension, but I freely admit I have neither the expertise or the facilities to make these work.
Couple of other things influenced the decision. First of all, although I did run the engine in the model, it never seemed very happy. Not surprised considering the tank issue. However, pulled the motor and run it on my test stand, and it ran so much better. Not familiar with 4 strokes, but 9,800 rpm on a 13 x 6 sounded pretty good. I mount my stand on a Workmate and the motor was trying to tow this across the field, so thrust is not a problem.
Also, in my kit mountain I have a Dave Smith Models Smart Move. Perfect size for the ASP, and being a kit I can choose my own tank location. Sounds ideal, and means the motor won't go to waste.
Win win.
Meanwhile what to do with the current model.
53 mounted sidewinder is very much an option, but a root through my box of junk (er, useful spares) revealed an electric motor, esc and battery just made for the job.
Decision made.
Thanks again for all your help
Jeff