Brison 6.4 question
03-09-2009 | 07:03 AM
#1
Thread Starter
Brison 6.4 question
Hey, guys. I had a little mishap over the weekend. While flying my 35% WH Sukhoi the motor came loose and rubbed against the baffle inside the cowl. Consequently the little linkage snapped off that connects the mechanical ignition advance ring with the bellcrank linked to the carb. I managed to fabricate a new one at the field, but had no idea what the exact length of that linkage was. After guessing the length the motor fired back up and ran fairly well. Was easy to start and transition was instantaneous. So was idle. But WOT I only could get 6100 with a Evolution 26x10. Anybody know how long that linkage needs to be? Any input is greatly appreciated.
03-09-2009 | 09:12 AM
#2
Senior Member
My Feedback: (264)
RE: Brison 6.4 question
ORIGINAL: thevirginian
Hey, guys. I had a little mishap over the weekend. While flying my 35% WH Sukhoi the motor came loose and rubbed against the baffle inside the cowl. Consequently the little linkage snapped off that connects the mechanical ignition advance ring with the bellcrank linked to the carb. I managed to fabricate a new one at the field, but had no idea what the exact length of that linkage was. After guessing the length the motor fired back up and ran fairly well. Was easy to start and transition was instantaneous. So was idle. But WOT I only could get 6100 with a Evolution 26x10. Anybody know how long that linkage needs to be? Any input is greatly appreciated.
Hey, guys. I had a little mishap over the weekend. While flying my 35% WH Sukhoi the motor came loose and rubbed against the baffle inside the cowl. Consequently the little linkage snapped off that connects the mechanical ignition advance ring with the bellcrank linked to the carb. I managed to fabricate a new one at the field, but had no idea what the exact length of that linkage was. After guessing the length the motor fired back up and ran fairly well. Was easy to start and transition was instantaneous. So was idle. But WOT I only could get 6100 with a Evolution 26x10. Anybody know how long that linkage needs to be? Any input is greatly appreciated.
To get the timing right you are going to have to time it like it was new. You will have to find TDC and then adjust the timing link length for 28 degrees total ignition advance at full throttle. This is the only way to get it right, anything else is just a guess.
03-09-2009 | 11:11 AM
#3
Thread Starter
RE: Brison 6.4 question
Hey, rcdude
I thought I could short cut that step by asking what the exact length should be
. I wasn't sure either what the ignition advance for my engine is. You are sure it is 28° for the Brison 6.4, correct? I certainly appreciate your help.
I thought I could short cut that step by asking what the exact length should be
. I wasn't sure either what the ignition advance for my engine is. You are sure it is 28° for the Brison 6.4, correct? I certainly appreciate your help.
03-09-2009 | 11:36 AM
#4
Senior Member
My Feedback: (264)
RE: Brison 6.4 question
28 degrees total advance is generic for all gas two-stroke model engines, you can go slightly more but it will not incrase power much and you run the risk of detonation. 28 is safe.
If you have never timed the ignition before, here is a good description of how it's done. This is how I time my C-H converted G-62's
http://www.ch-ignitions.com/CHinst.html
Mike
If you have never timed the ignition before, here is a good description of how it's done. This is how I time my C-H converted G-62's
http://www.ch-ignitions.com/CHinst.html
Mike
03-09-2009 | 07:16 PM
#7
RE: Brison 6.4 question
thevirginian, rcdude7 has offered solid advice . Follow the instructions from C&H and set the timing by adjusting the length of the rod . I have 2 Brison 6.4's and the rods are not the same length . A static length check does not insure correct timing ,it has to be checked and adjusted. I also checked my 3.2 engines and none of them are exactly the same either.
] I guess I will have to do it the hard way.
