5.9 tuning issues!

[Tyson Adams]

Hey guys, I just got a 5.9 pretty much brand new and broken in I'd imagine, and put it in the 4.6. Other than obvious changes like the transmission and gear ratio, it's virtually just a swap. The Sav is already beefed right up in the drivetrain so all should be good. After install, I've started it and idled and began trying to test and tune. I restored the needles to factory and it took off fine until it hits mid range. It bogs right down and won't change into second. I've fiddled with every which way combination of settings and not even getting close. It overheats within 5 minutes and that's not even doing hi speed passes yet. Running a cold plug, os 10, A3 and a HPI R5. I've tried an Os 7 and 8 all the same problem. I ended up with the hi speed wound way out from factory to the point where the needle comes lose. Still over heating, bogging in mid range and won't snap second. Not even close. It's just not getting the RPM it needs, but running hot? Now I'm a pro at tuning engines and mastered the 4.6 but this has absolutely got me stumped.binthought it could be the inline fuel filter but no, that would affect entire rpm not mid range onwards. Maybe the previous guy has played with the mid range needle which I've heard is a big no no. And also a lot of guys are dead set against the 5.9. Maybe a seal in the carb? An air leak? That's all I can think of. There's not a great deal of info on the 5.9 tuning online and I don't know where else to turn. I'm hoping that someone here has seen this problem or can help me out? I'm stuck and ready to change back. Cheers heaps in advance 🙂

 

[Jr.]

THe first thing that jumps out at me is, is it really broke in? "Pretty much brand new and broken in I'd imagine", sounds like you bought it used?

 

[X]

I agree with Jr. I would go through break in as if it were brand new. Unless you know specifically how the engine was broken in and run previously. Also, that cold plug is not going to help you. What fuel are you using? Likely you should be using a medium plug, like the OS #8.

This seems to me to be a good opportunity for you to disassemble the engine and verify that everything looks alright. And while you are at it seal the engine up good.

 

[Tyson Adams]

Yeh sorry mate I didn't word that right haha. I meant like it's still in the brand new category as far as engines go, but it looks as tho it's done a little work. And the needles had been tuned in. It could well be that that is the problem. I just figured it had already been done. It cuts out if I rev it too hard off the ground. But even then it won't go through the mid range. Not even close to high speed.

 

[Jr.]

I think it's likely it can't achieve the rpm needed for the shift because the pinch is still too tight.

 

[Tyson Adams]

I also ran an os7 and 8 when trialling thinking that it was causing it to overheat I switched to cold. I had an issue with the 4.6 high speed needle where the o ring went in it and it would start, idle take off then stall. This current problem isn't as sharp tho like it bogs and then will idle. Then stall. And bubbling fuel like its way too hot! But pissing out fuel from the exhaust. I'm thinking air leak in the carb maybe. Any thoughts?

 

[Tyson Adams]

I just asked the bloke I got it off he said he put 30 tanks through it and it run fine haha. Ahhhhhh bloody hell

 

[Jr.]

I'm not intimately familiar with th 5.9, but I have read a ton of reports of the mid range needle being problematic

 

[rcnut14]

if fuel is coming out of the pipe ur runniing the hsn too rich

 

[Tyson Adams]

But it's cooking itself so it's way too hot I can't lean it in anymore. Must be a leak hey

 

[Jr.]

Have you sealed it? Backplate, O-rings?