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Hey guys, took my savage 3.5 out today

I'm still having problems with my tuning,

The savage idles comfortably, when i fully accelerate it hesitates before taking of, if i am gentle with the lever the savage gains speed but then when at full throttle it starts to hesitate again.


i have a tuning guide and it says that if it suddenly dies or looses power then richen the HSN,

It also says if it suddenly bogs or dies then Lean out HSN

what is the difference between loosing power and bogging?

and any tips on easier tuning?
 
If there is excessive smoke, your rich. If the stream is hard to see, or your engine sounds hickupy, It's probably lean. What's your temps?
 
i have a hard time hearing a lean tune. an overly rich tuned is easy to hear. if you hit the throttle, and the RPMs start to increase then they suddenly drop. your most likely rich.
 
For what it's worth here's an experience I had with an HPI 3.5.
I drilled out (enlarged) the venturi and reset the three needles/screws to what they were before I did anything.

It idled fine, but when I gunned it from a stop it moved off the line ok and then a split second later kind of coasted (like it was starved for fuel) before catching it's wind and moving on.
I interpreted that to mean that my drill job upset the low end setting and that it was lean at that point before the HSN's setting took over.
I richened the LSN which took care of that issue.

Bogging on the other hand (to me) means that it's getting too much fuel and it tries to burn off what it gets and then is overwhelmed with the excess fuel and it bogs down.

Maybe someone like Scrogg can point out exactly what your issue is, but I think you need to adjust your LSN as well as your HSN.

Do you have a temp gun?
If so, what temp are you running?
When you're at speed, is there a steady stream of smoke?
Also - how old is your fuel?

What are your needles current settings (how many turns out from fully (gently) closed?)
From the HPI 3.5 engine manual.
The HSN is factory set to 3 1/2 turns. after break-in, the needle can range from 2 1/2 to 3 turns from fully closed depending upon humidity, elevation, fuel and glow plug.

The LSN is factory set to 3 1/2 turns. after break-in, the needle can range from 2 1/2 to 3 turns from fully closed...

"The mid-range adjustment screw is pre-set from the factory to 3 1/4 turns from fully closed. It is recommended that you do not adjust the mid-range adjustment screw."
 
Thanks guys.

Have tried to go back to stock however i have a problem.

The LSN when you close it all the way in. then taake it 3 1/2 turns out. when you push the throttle the (bit that comes out of the engine that connects to the servo arm) doesn't move, you have to release the LSN another 4 turns before it moves.

why is this?

Also

Sometimes the fuel wont go to the carb when starting, even with your finger over the end of the exhaust. what could cause this?

Many thanks.
 

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