HPI engine identification

[Mixy]

Hello, I bought used HPI engine few years ago but I cant indetify it. I thought that it is nitrostar K4.6 but K4.6 has one more needle on carb and mine not. Then I thought that it is F4.1 but this one has different "HPI" logo on engine body. RC mode: Savage S-25. Thanks

 

[X]

To me, that looks like an hpi K4.6 engine with an STS carb. Looks just like the carb on my D30M. Is there any labeling on the front of the carb?

 

[Mixy]

You are right. Body of engine looks like K4.6 and on the front of the carb is label "STS". So question is: How to setup engine with this carb to factory setting? If I flush needles(according to K4.6 manual) engine runs badly or even doesnt start.

 

[X]

I'm guessing someone didn't like dealing with the mid needle, so they swapped to that carb. There is likely no "baseline" tune since the carb and engine are not matched. Just keep adjusting from the stock K4.6 settings until you get to a spot where you can run. Get it good and warmed up and tune like normal.