K4.6 or F4.6

[wt22063]

I know I have seen it here but not sure where to look. What are differences and how to know a K4.6 from a F4.6?

 

[J.LO's SAVAGE X]

a k 4.6 has a 3 needle carb and the head is not perfectly round, it has notches cut in the cooling fins the f 4.6 will have a purple or grey perfectly round cooling head and a black crankcase, with a 2 needle carb

 

[jay2006]

a k 4.6 has a 3 needle carb and the head is not perfectly round, it has notches cut in the cooling fins the f 4.6 will have a purple or grey perfectly round cooling head and a black crankcase, with a 2 needle carb

and to add to that..HPI has rated the f4.6 @ 2.75 hp and the k4.6 @ 2.9hp. however i do beleive the newer f4.6 is now putting out 2.9hp.i believe some other more technical diffrences are cylinder sleeve, porting, carb opening in crankcase is larger on the k4.6, and from what ive heard the k4.6 is a pain in the rear to tune expecially if your a beginner.i have a k4.6 myself but i havnt ran it yet. i got it in a trade with low compression so i rebuilt it and put it back in the box.my advice is LRP!

 

[J.LO's SAVAGE X]

You can get a 2 needle carb from a f 4.6 to use a take out the 3 needle carb

 

[mr havoc]

I'm on my second Savage with the K4.6 and both have ran well

 

[J.LO's SAVAGE X]

yes they are a great motor, but I'm one of those people who get frustrated with 3 needle carbs, I'm not the greatest tuner, lol, so 2 needle carbs help out.

 

[jay2006]

yes they are a great motor, but I'm one of those people who get frustrated with 3 needle carbs, I'm not the greatest tuner, lol, so 2 needle carbs help out.[/QUOTE AGREED ON THE 3 NEEDLE CARB. I'm DECENT AT TUNING BUT IF YOU don't HAVE TO DEAL WITH THE HASSTLE THEN WHY DEAL WITH IT? 2 NEEDLE ALL THE WAY!!

 

[mr havoc]

If you have a 3 needle carb the MSN is best left at factory settings and sealed off, then forget about it

 

[jay2006]

If you have a 3 needle carb the MSN is best left at factory settings and sealed off, then forget about it

YOU GOT THAT RIGHT!!! i bought a brand new mgt 8.0 september 2016. during breakin i started messing around with that mid range needle and it was the worst head ache ive ever had in my life as far as nitro engine is concerned!!! even called team associated and ended up having to send engine in for warrenty and they went through the whole engine ,made sure there wasnt any damage to piston and sleeve, installed it in there test truck and tuned it for me..sent it back and the technician said "don't ever touch that mid needle!" then he said.."i don't even know why they put them on the dam thing!"i know how to adjust them but the one way bearing cracked and the backing plate came loose so i figured one way bearing is 50 and a whole month back order. plus with loose backing plate i know it was running lean so i wanted to make sure no damage was done. i got a gallon ran through it and its an absoulute beast!!nothing like my savage with lrp 32 though lol

 

[J.LO's SAVAGE X]

that k 4.6 was always a really good motor.

 

[GLISEON]

Are you guys sure the f4.6 carburetor can fit on a k4.6? I just recently purchased a k4.6 and don't want to struggle with the headaches of a msn. Or if I were to seal the Msn, which sealent should I do it with ?

 

[Novacobra42]

Are you guys sure the f4.6 carburetor can fit on a k4.6? I just recently purchased a k4.6 and don't want to struggle with the headaches of a msn. Or if I were to seal the Msn, which sealent should I do it with ?

First of all only racers Pros adjust the MSN the average user will not need to adjust it the whole purpose of the MSN is to get a little better acceleration at low and mid engine speeds speeds so they can get better acceleration out of the corners while racing

The factory setting is near perfect for the average user adjust your high speed needle first after you run at least half a tank of fuel through the engine making sure that it is at full operating temperature having a temperature gauge is beneficial cuz you want to keep the temperature below 240°

A lot of people will say 220 to 240 degrees many will tell you that these engines run great at these temperatures and truth be told they're right the problem is the longevity of the engine will drop dramatically if you turn your engine correctly at Full Throttle in first or second gear you'll have a nice faint trail of smoke personally I have changed to the O'Donnell speed blend and it is the best fuel I have ever used my son and I have a Savage X 4.1 a Savage XL a Savage Flux and M GT 4.6 and MGT 8.0 and to Traxxas one off road truck and one on road car I have used Morgan fuels I have used I think it's Wildcat but I have found that the engines run cooler and are easier to get tuned into their Ideal Power Band using the O'Donnell speed blend fuel good luck and have fun with your truck many happy hours of flipping and jumping

P.S. make sure to use an HPI R5 or a McCoy MC - 9 glow plug will the years I've tried OS and every other company out there dhpi and McCoy seem to last the longest