Savage X K4.6 Engine dies when opening throttle

[mrseldowski]

Haven't used the engine for maybe 4-5 years, opened it up and cleaned it all up.
Soaked engine/carb in nitro fuel
Lubricated all engine parts with after-run oil and re-assembled

Using Traxxas 20% fuel (mostly because its all I can find around here).
Engine started pretty easily (R5 Plug) and idles fine, but when I try to accelerate more than like 30%-40% it starts shaking and then cuts out.
I tried adjusting the needles for a LONG time. Started with factory/flush and mostly leaned out the neededs, but no matter what I do/how long I leave it idling to warm up I still have the same issue.
Compression seems good to me, and I checked the fuel tank pressure seems good I think? Maybe the fuel tank o-ring old but it looks okay.
Any tips or is this engine toast?

 

[Gazzman]

Maybe it's leaned out to far and getting fuel starvation. Have you tried giving it abit more fuel instead, wind the HSN out abit passed factory setting. Had similar problem on 1 of my K5.9s at the weekend, it didn't start shaking tho just kept cutting out. Would accelerate off well than after 3 -4 seconds of giving it throttle sounded like it was misfiring and if kept gas on would die.
I doubt if the mill is toast, sound like carb issue to me. If it's got good compression and starts and idles well would say it's good.
You say it's a K series with the mid range needle. never change this needle, always leave it flush with 1 of the 2 holes in the inside of it facing up so as the fuel from the inlet has a straight path through the needle. Unscrew the banjo where the fuel enters the carb and you can see if the holes are lined up on the MRN. Once set never change it. I put a small piece of tape over the end of the needle once set flush as they have a habit of moving.

 

[Gazzman]

PS. the K4.6 is a right pain in the arse to tune good. I have 2 K4.6HO mills and can never get them to run any sense for long but if you get it right they fly. The HO mills are the ones with the black crankcases, pushing 2.95hp