brownviper1966

HI Guys,
I m totally new to the nirto world (4 wks experience)

My first motor is Kyosho's pureten GP2 1\10th rally car with .12 pullstart engine.

I ran the engine in using 20% sidewinder fuel; though not sure I did it right because the engine was left reving about middle throttle most of the time to prevent it from cutting off , however after the run-in the engine runs and starts.
Now, my problem is that i cant keep it idelling for a long period of time without it cutting off. I tried to lean and richen the fuel/air mixture with no success. and also, if I pull the throttle for full power the engine kind of chockes and most times needs restarting. I changed the plug with no difference . I switched to 10% byron fuel; after a better run-in procedure this time round,,,,,,,,,,,,,,,, and still the engine isnt right.
I wonder is the engine (kyosho purethen .12) really bad, and I need to get another engine that is more user friendly and reliable?

OR

shall I cut my losses and get another nitro kit all together, as the current .12 engine is driving me mad


Please Help an newbie to get a grip with his nitro hobby

brownviper1966

^^ ^^
anyone?

Genius

Is your engine the GS11-r? has only one needle aside from the idle screw? Is it brand new?

brownviper1966

yes, thats right

Genius

the GS11r aint the best engine but it should still be able to run properly. Breaking in is very important wherein you should take your time, the extra effort will reward you with a better running engine. I hope that when you did the break in the engine it was very rich and a lot of oil was coming out.

Anyways for normal running you can start by closing the main needle (turn it clockwise) and then open it around 1 3/4 turn to 2 turns(counterclockwise), maybe a better idea to start with 2 and then just close it a little depending on how it runs. That engine normally likes those settings. then just set the idle maybe 1mm opening, or set it low enough to keep the clutch from engaging and high enough to keep it from dying. The 20% fuel should do just fine.

Genius

Also it might be difficult to find an engine that will fit the car. Although iv seen it been done before its not a very good idea cause the Pureten wasnt designed for a very powerful engine. So the car, especially the drivetrain has a hardtime taking the extra horspower.

luke_morrow

brownviper1966,

I am new to the game also, but i found a few things with my Kyosho GXR-15 engine that may worth a check on your car:

1. If the engine keeps cutting out when backing off from high throttle, IMEDIATELY check that you are not missing screws from your exhaust. I was very lucky in that I found one that went missing in a large area! Other symptoms also included a rougher sound at idle (ie. exhaust gas not going through the exhaust). The rubber gasket probably needs replacing now ... but i've sealed it tight enough and put thread locker on the screws to be safe (note that the heat from the exhaust means i will be checking that the thread locker is secure ... on a regular basis).

2. Just double check that your carbie is screwed on snug and tight, otherwise it doesnt idle for more than 2 seconds. I had that problem and at first i though it was supposed to rotate to align with the servo at all times. Then i checked the maintenance manual drawings and found that it could be tightened ... and so i did and it made all the difference.

3. Try writing down the settings for the idle mixture screw, needle valve and idle adjustment screw and then set them to what your manuals say. Find the best of the two settings and use it as a base point to better tune the motor. Each time you find a better setting write it down and see if can be improved. Sounds like you might want to check the Idle adjustment screw (not mixture) for better idle. Mine is set at about 1.15 turns from in fully.

I dont know if this will help your problem ... but it might just save you some money to get it running well until its time to upgrade.

If you cant fix the problem with this help ... and still want to save money for the short-term, record an mp3/mpeg/other of your engine running from idle to 80% max rpm ... then zip and attach it to a post. Experienced racers should be able to tell straight away by sound ... and seeing the trail of exhaust smoke under power.

Goodluck ...

Luke

Rapid Roy

Also you can't let a nitro engine idle for more then 15 seconds without blipping the throttle. Fuel tends to collect in the case and "load up", which is causing the sputtering you are describing. There are a couple of pretty good engine tuning tutorials floating around this forum. Maybe somebody can point to one for you.