Bass1

I have an old mechanical advance Brison 3.2 with a CH ignition. I need to check and reset the timing on the engine due to a mishap and subsequent change out of the timing and throttle linkage. There used to be instructions/timing wheel printout on the old CH Ignition website on how to set up the wheel and make a pointer to check for 28* BTDC at max throttle. Anybody have those instuctions or diagram to show me how to set up this system and use it? I thought I had it set up properly by copying the length of the rods from another Brison engine I had but the hubs and timing rings are different sizes so I'm sure the rods are different lengths as well so it didn't translate and I'm getting a miss/detonation at max throttle so I'm quite sure I'm too far advanced. Thanks in advance (no pun intended

BadAzzMaxx

Are you using the original CH ignition that the timing is fixed in the ignition, If so you can set it at full throttle and use the method in the link below.

http://www.rcextremepower.net/ignition_timing.html

Milton

All Day Dan

My Feedback: (5)

Milton is being modest. His classic video will really help. Dan.
http://www.youtube.com/watch?v=GBXFpxWg7vY

w8ye

My Feedback: (16)

I have always used Milton's classic video method for the last 15 years anyway.

Bass1

Thanks Milton for the video and thanks Dan for for the link. I found my old C&H timing wheel printout and made the unit with light ply and soldered up a nice clip on pointer. I found that my ignition was timed at 30* BFTDC at max throttle. When I reset (shortened) the timing linkage to 28* BFTDC my engine came back to life and the missing/detonation was 99% gone. I shortened the lingage one more turn for good measure and the engine runs smooth as silk through out the rpm range. Although it was about 20 degrees cooler outside than yesterday when I had the issues so I'm also going to pay very close attention to adequate cooling as well. I'm fairly certain that retarding the timing a tad was the fix. Does a mere 2 degree change in timing make that much difference?? It sure seemed to on my engine! I also opened up the front end of the cowl a bit to expose more/all of the cooling fins and enlarged the hot air exit in the bottom of the cowl as well. Would you guys baffle (close off) the two outside cowl cheek openings as well for best cooling? I've had a few similar airframes in the past using the same motor and left the cheeks open with no problems. Be a very simple proccess to close them off as it's the beginnig of summer and it's just going to get hotter...