Cannonball3
Well-Known Member
- Local time
- 5:10 AM
- Joined
- Sep 11, 2021
- Messages
- 845
This is for all you experimenters out there. This is on my low end Minareiil that runs a stock exhaust. Its gutted and has three 1/4” additional holes. After going thru the jetting/needle adjustments it runs very well. With one exception-off throttle/low throttle surging. I finally concluded
it was probably a back pressure issue or lack there of. So I modified the cap to be adjustable. After much experimentation this is what I arrived at.
With all holes open it was prone to WO 4stroking. I stuffed the three holes with coarse steel wool and that improved the 4stroking, and ran great overall, but still surged at cruise/ light throttle. After adding the cap and a bunch of test riding, the ideal setting was 3 partial holes, with none of the original opening. Was quieter, smoother and low and mid improved, no surging. Amazingly it still had 35 top end. It will top around 42, ports wide open. I ride thru a lot of quiet neighbor hoods to get to town so smooth and quiet is important. The cap is retained by the mufflers bolt and has a stout compression spring to hold settings.
Just throwing my experiences out there. If you ride 3/4 throttle all the time surging wont bother you. It suck's at light cruising. All builds are different, so you are on your own figuring out yours. This worked for me.
it was probably a back pressure issue or lack there of. So I modified the cap to be adjustable. After much experimentation this is what I arrived at.
With all holes open it was prone to WO 4stroking. I stuffed the three holes with coarse steel wool and that improved the 4stroking, and ran great overall, but still surged at cruise/ light throttle. After adding the cap and a bunch of test riding, the ideal setting was 3 partial holes, with none of the original opening. Was quieter, smoother and low and mid improved, no surging. Amazingly it still had 35 top end. It will top around 42, ports wide open. I ride thru a lot of quiet neighbor hoods to get to town so smooth and quiet is important. The cap is retained by the mufflers bolt and has a stout compression spring to hold settings.
Just throwing my experiences out there. If you ride 3/4 throttle all the time surging wont bother you. It suck's at light cruising. All builds are different, so you are on your own figuring out yours. This worked for me.
Attachments
-
0B9BAFFD-59EF-415B-9AA2-3409B9602CD3.jpeg95.4 KB · Views: 109
-
B2DAC2D6-EA2E-4AC8-8189-7DD47D170EFD.jpeg89.9 KB · Views: 92
-
917A2F30-B939-48C3-AECD-E9F999973EAE.jpeg91.2 KB · Views: 91
-
B6947C5B-2B68-429E-811C-5D0620FB2276.jpeg114.6 KB · Views: 93
-
0A3D6FFB-37E8-45E1-9749-FA62807C65F6.jpeg465.9 KB · Views: 110