Set mid and forget it.

Set the mid to 2 turns out from flush at 2 oclock and leave it there. Then it will adjust like a 2 needle carb.

Guess is over rich hsn o weak plug... Thanks

Having serious problem to fine tune, when WOT, feel like starving for fuel but still extreme rich hsn. Change 2 new plug but same problem. 10th tanks...

Hsn-3 turn out from full close
Msn-2 turn out from flush 2pm
Lsn-1.25 turn in from flush

Plz assist

Have you fiddled with your idle gap? Make sure the idle gap is small - like 1mm or less.. As you close the idle gap, you generally need to lean the LSN to raise the idle back up - and vice versa.. I'm not a tuning expert, but often I find richening the LSN helps get things in the ballpark if a tune is playing hard to find... (but that is sometimes also compensating for a too-big idle gap..) The trick is finding the balance between the idle gap and the LSN - the HSN is simple..

All I've ever heard about MSN's is ... don't mess with them.

Yes with msn. For idle gap n lsn is correct. I just need expert opinion with 3 needles carb. Cant seem to make it dial

I did some reading, i think my tune got problem in the transition from mid to top end if the plug happen to be good. Should i lean the mid needle .5turn n richen lsn .5turn. I think just leave the hsn rich for safety. Any opinions? Thanks in advance

I would lean the top to 1.5 turns out and see what is does on a full throttle run. If it cuts out, then richen it and re-test. The bottom end is mainly for idle speed. If it won't clear out from a 10 second idle, then lean the bottom also.

The pipe, plug, and fuel will change what the top and bottom needles need to be set at.

fuel
 

It might be your fuel. You said you added 2 ounces of castor oil. That is twice what I would add although I am not familiar with the brand you mentioned. Just an idea.

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Replace tank

I run 5port n 2103 arrow pipe. Any recommendation for better power band n fuel efficiency. From this forum os 2060 not suitable on 5port.

i have one of the gen 1 3 port engines and i hated the carby on it. was difficult to tune and seals were crap. ever since i put the 2 needle carb from the MG66 on it it has been awesome!

From what i learnt in this forum. Is a good carb. Get the msn set then dont tune it. It it tune like 2 needle

Yes the carb is good now, you just have to have the mid range 2 turns out from flush at 2 o'clock. Then it tunes just like an OS carb.

The seals and the carb insulator have all been improved since the original version also.