we have a

1247 or 1257 mate? i cant find anything for a 1247,
besides that, do you have the radio gear connected and turned on?
or no linkage fitted yet?
if no linkage then is there a return spring on the carb? or is the carb opening under the weight of the throttle arm when tipped forwards?
if radio is fitted with linkages etc and turned on,
are you using a gyro of some sort that you connected through the throttle/brake channel/servo by mistake?
of have a loose connection somewhere and when you tip the car forwards it loses signal and the failsafe kicks in but goes full throttle instead of full brake?

1257 .
radio is conected and turned on.
linkage is all fited.
radio and linkage are all fited and working properly.
no gyro.
don;t know of any loose conections.
i just don;t know.

can you post a pic or two of your linkage setup mate?
then some of us might see sommat obvious possibly,
and/or fire the car up again on the chair, look at the linkage/servo when you tip it forwards and see if theres any movement in the linkage, or if the throttle/brake servo just has a mind of its own when tipped forwards,

Take your linkage off and start it to see if it has the same issue. If it does, it's likely an air leak, or your throttle shaft could be jammed. Also your idle screw, check it

here are some pictures.

I'd switch spots on that brake/throttle. They look like their crossing eachother in an X you want linkages to be linear and in line with what their actuating

this look better?

that is much better than the previous setup

Looks good now

that seeto solve the problem of when i lift the car off the chair when it is running going to full row for another problem.
when i hit the brakes the engine will stop.
what can be done to stop this/
thx D

Idle screw needs to be set.

thx that seemed to fix it.
now if it wasn;t raining out i could go play with it.

well got to play with it yesterday.
after much fiddeling with it i got it running pretty good.
man that pipe is loud.
ran it for about 20 min and it just locked up would not go motor was running.
took it over to buddys house and we took it apart and discovered one of the screws had backed out and was hitting main spur gear and would not let it move.
fixed that than we went out to run it again and got it finer tuned.
he left before id and after a while it started running funney so i stoped it and it would not roll on the ground just like before.
took it home and discovered the same thing happened as before but it was a different screw this time fixed this and it is waioting for the loctite to cure all the screws on the tranney plate got a dose of loctite.
fun eh?

Any bolt that is metal to metal needs loctite. Even grub screws.

guess i will need a gallon of loctite.