posted
I have a Mugen MBX4-XR with a .21 S7 engine. My question is about tuning the high end. I have been told to run the engine around 240 degrees. check this with an infrared temp gun and I search for the hottest point on the base of the head. I have read that some people run the engine as high as 260 degrees. At top speed there is still smoke coming out of the exhaust and the temp is around 240 but I checked the glow plug (O.S.#3) and it looks dull, as if its lean. If I richen the mixture it doesn't seem to have as much top end. What do I do? I don't want to ruin my engine. Obviously temp is not the most important thing because I am sure that 240 degrees on a cold day is not the same as 240 on a hot day as far as mixture goes. It seems I am always adjusting the carb. Help!
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posted
If you use a Raytek or similar device to measure your temperature, be sure to measure the glowplug. Its seems what you are doing is O.K., however we do not know how the other brands glowplugs resist at high temperatures, our experiences are based on our glowplugs, so we really advice you to try and use our glowplugs, if you are able to get our engines you should also be able to get our glowplugs.
Posts: 5412 | From: Allevard, FRANCE | Registered: Jul 2002
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jtlittle
unregistered
posted
You may be getting detonation from too hot of a glow plug. Try an RB-6 or RB-8 plug and see if your sensitivity problem goes away. I always run a RB6 and on extremely hot or humid days an RB8. I also run 30% fuel with an added .01mm head shim.(.004in.)
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If detonation happens it is not due to the glowplug but due to the compression(volume of combustion chamber + space with the piston in TDC), the main needle setting the top rpm the outside temperature, altitude and humidity.
Changing just the glowplug will not really solve your problem if you have one. However we noticed that if you increase the volume by adding shimms the engine becomes easier to set but less powerfull.
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