Requesting advice on troubleshooting a flat spot

mcvetyty · Post by **mcvetyty** » Mon May 25, 2015 3:34 pm

Hello -

I have a 2008 Stella 2T with a sidecar, that has a Pinasco 177 and a Sip exhaust. My jet stack is currently:

55/160
160
BE4
118

The BE4 is a change that I just implemented in order to try and get rid of a flat spot that I am experiencing in the lower 1/3. The BE4 DID help slightly, but there's still a flat spot.

My question is, what's should I adjust next? In reading threads, I am very confused on the BE3/BE4/BE5 debate, so I am unsure if a BE5 would help. Or, if the BE4 is the max atomizer, should I adjust the idle jet next? What would be the next size from my 55/160 in the line?

Thank you!

mcvetyty · Post by **mcvetyty** » Mon May 25, 2015 4:39 pm

Update. I just took it for a nice long ride and from what I can discern, I'd say the flat spot occurs right at the 50% throttle mark. It sputters briefly before taking off again.

Based on that, are there any thoughts as to what my next adjustment should be?

Appreciate the help!

BuddyRaton · Post by **BuddyRaton** » Mon May 25, 2015 9:00 pm

Are you running any temp gauges.

mcvetyty · Post by **mcvetyty** » Mon May 25, 2015 10:22 pm

Yep! Never goes higher than 240.

mcvetyty · Post by **mcvetyty** » Tue May 26, 2015 10:10 pm

Any other thoughts? I'm mainly just looking for confirmation on three things:

1) Does this symptom (hesitation/sputtering at about the 50% throttle mark) warrant a richer or leaner jet?
2) Is the BE4 the max jet in the direction I need to go into, or would a BE5 be an option?
3) Seeing as though its right around the 50% mark, should I try to adjust the idle or the main one iteration? And if its the idle, what is the next one after 55/160?

viney266 · Post by **viney266** » Wed May 27, 2015 1:51 am

It is lean. I am sure, went through this with the same kit.

A bigger idle will help, but not solve the issue, check your PM's