Newbie in need of help

[Robman23]

Hi firstly I would just like to apologise for another newbie needing help thread, however I really am stuck so need some advice.

I have a thunder tiger tomahawk vx 1/10th touring car. It is my first nitro car and to be honest it is far more trouble than I had ever imagined. I picked nitro over electric as I wanted something that I could tinker with. I got it back last September and got on really well with it. Got it tuned alright and running well. Put it away for winter, came back to it last month and snapped a couple of pull starts so decided to buy a rota start which I must say is brilliant, however on that note I can't seem to get it running properly since fitting this. When I removed my engine to fit it I messed up my tune and now cannot find default settings. I can get it to start up and idle, but the revs start to slowly build up and just keep steadily going up until it goes mad and I have to pinch the fuel line. Also if I even touch the throttle it goes totally mad like I have put on full throttle and left it on. When checking the idle gap it is fine - I did think it had stuck open but it seems fine. Does anybody have any ideas what I can do to fix or even anybody live locally (Leicester) want to have a look? Will gladly pay for your time.

Any help please will be hugely appreciated.

[Joe_K]

Sounds like it's lean (not enough fuel in the fuel/air mixture).

Here's the manual by the way, page 7 is where you need to be looking:

http://mms.tiger.tw/upload/upload_file/CAR/6194_manual.pdf

Anyway, to set up the carb:

Start the engine and turn the low-speed needle (figure c in the manual) anti-clockwise to increase(richen) the fuel flow. Turn it in 180 degree increments until your engine is idling at a constant speed (not going constantly up like you say it is). When you have it idling correctly, pinch the fuel line and see how long it takes to cut the engine out. You're aiming for 5 secs or so.

For the high-speed needle, you should have a temperature gun.

http://www.maplin.co.uk/p/infrared-thermometer-with-laser-targeting-n92fx

or

http://www.maplin.co.uk/p/pocket-infrared-thermometer-n19fr

should do the job.

Drive the car, accelerate at full throttle for a second or two. Listen to the engine. It should sound crisp and clean - it shouldn't bog down as it accelerates. If it does bog down, this could be a sign of the high-speed needle being too lean also. Again, turn the high-speed needle anti-clockwise until the car sounds clean under acceleration.

Turn the idle screw to increase/decrease the idle speed as necessary. This sounds vague I know - what you need to do is run the car for a little while, so it's warm. If (having set the two needles above), the car keeps cutting out when returning to idle, then either the low-speed needle is too rich (shouldn't be as you set it up earlier) or the idle is too low. If the engine runs on (higher than you want) when returning to idle, then either the low-speed needle is too lean or the idle is too high.

To richen (opposite to lean) the mixture of a needle turn it anti-clockwise

To lean the mixture of a needle turn it clockwise.

Use the temp gun and point the sensor at different parts of the heatsink, you want the engine to be no warmer than 90-100 degrees C. If it's too warm, richen the top-end needle a little (1/8 of a turn) and go again for a minute or so and then temp it again. Repeat till you have your temperatures under control.

Buy some after-run oil (http://www.modelsport.co.uk/hpi-engine-after-run-oil-50ml-/rc-car-products/35806). Once you've finished running your car, kill the engine, close the throttle, and put some of this oil into the carb - fill it so the oil sits a couple of mm deep in the carb opening. Now turn the engine over with your starter (DON'T use the glow start, we're just getting oil into the engine to protect the internals). That's it!

Hope this helps, I have no doubt other people have other ideas about engine tuning and maintenance but this will certainly help you to get a good base setting for your engine.

[Essex2Visuvesi]

If you have a 1:1 car with automatic transmission you can use ATF as after run oil.... Its the same stuff