I have a CMB .67 Greenhead in my 1/8th Scale U-3 Chrysler Jeep.
I have the stock remote needle valve opened one turn for the servo arm. Currently I am running 40% nitro, as I do not race. I was wondering how many turns to open the hex head of the needle valve. More details below.
I have been breaking the engine in and have run about 3/4 of a gallon through it. It is still running slow but continuing to get faster each day I run it. I have the hex head opened up about 5 or 6 turns. At one point, I was at 4 turns and it was running very slow. I kept opening it up until about 6 turns and it is now running faster than it ever has. However, it still is only running around half throttle. When I increase to 3/4 or full throttle, it slows down to what seems to be about 20% throttle, even though the carb is wide open. If I decrease throttle to about 30% and increase back to 50%, staying at 50% throttle, it runs its best.
When I start it on the stand, I have very good response from the engine, matching the carb opening closely. I can idle it, mid-range, and give it top-end briefly and it responds well. It doesn't seem to reach those rpms once in the water. I realize there is a load from the prop but the engine actually bogs down if I go above 50% throttle in the water, whereas on land it will increase accordingly. What should I do to get more rpms on the water? I am running an octura 3-bladed prop
Thanks for your help guys.
I have the stock remote needle valve opened one turn for the servo arm. Currently I am running 40% nitro, as I do not race. I was wondering how many turns to open the hex head of the needle valve. More details below.
I have been breaking the engine in and have run about 3/4 of a gallon through it. It is still running slow but continuing to get faster each day I run it. I have the hex head opened up about 5 or 6 turns. At one point, I was at 4 turns and it was running very slow. I kept opening it up until about 6 turns and it is now running faster than it ever has. However, it still is only running around half throttle. When I increase to 3/4 or full throttle, it slows down to what seems to be about 20% throttle, even though the carb is wide open. If I decrease throttle to about 30% and increase back to 50%, staying at 50% throttle, it runs its best.
When I start it on the stand, I have very good response from the engine, matching the carb opening closely. I can idle it, mid-range, and give it top-end briefly and it responds well. It doesn't seem to reach those rpms once in the water. I realize there is a load from the prop but the engine actually bogs down if I go above 50% throttle in the water, whereas on land it will increase accordingly. What should I do to get more rpms on the water? I am running an octura 3-bladed prop
Thanks for your help guys.
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