5.9 in X Leaning Out

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gator

gator

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48
Location
Mississauga
Last year I pulled out my 4.6 and unfortunately went and got the 5.9. I seem to be having trouble with the engine leaning out after 2 tanks of fuel. I recently found a bad o-ring on my high speed needle, which I replaced. Truck ran well with the 1st tank although by the end of the second it was doing the same thing. Should I bite the bullet and go and replace the 5.9 now or is there something I may have missed? I've re examined the o rings and they all look good.

Gator
 
I say replace it... But I hate that mill. I am a firm beliver that if it needs to be sealed to run its best in the trash can.
 
I'm starting to think Bankrupter has something, all my seals are good, I would hope that the seals would last longer than 1/2 a gallon of fuel. I'll do another quick check however, Thanks guys.
 
Mid range needle needs to be flush and sealed...major air leak there will cause you to lean out.
 
i agree j.... i have seen them walk out. also....check your gas tank top and fuel & pipe lines....
 
This motor is known for leaning out for a few reason. Do you have a stock fuel tank installed which is a standard Savage problem? What pipe and header combo are you running on it? What Gear Combo?

The stock XL header and Polished Pipe is boardline for the motor and the pressure is not enough causing it to lean out at half to full throttle more and top of the fuel tank issue equals motor disaster!! If you installed the K5.9 in a standard Savage X with the stock 4.6 header the pressure is really out of wack a more of a lean out on top of the tank issue.

The polished pipe (part number 86138) that is stock on the XL is the same old polished pipe that makes a 4.6 scream which means that THIS PIPE WAS DEVELOPED YEARS BEFORE THE K5.9 HIT THE STREET!! Talking about cleaning out the parts bin! :duh: That pipe is GREAT for the 4.6 but for the K5.9 its like a golf ball pushed through a water hose!! But hey, what do you expect for a truck that has wheels flaking off paint out of the box!! Sorry to say this but Very Disappointed in HPI's quality control lately!!!

If you do have the 4.6 header on it, all you will need is the XL header and the XL pipe hanger, BUT you will have to convert to one shock in the rear or get a set of Big Bore Shocks. This will help some but you will still have to run it fatter (richer) than other motors so it wont lean out.

If you looking for speed change the gear combo which is another choke on the motor. The stock XL is 16T/52T. I would suggest 17t/49t. That combo will help wake it up some.

Bottom line: Its in the pipe and the half tank lean issue. If you got any questions.
 
Cheers Modified, I am using a Buku pipe and the 17/49 combo. I replaced the fuel tank lid with a spare I had lying around. The fuel lines were also replaced with new. I'm going to try sealing it.I recently picked up a set of Big Bores from ebay. I was actually questioning the set up with the Buku pipe as a cause.
 
Gator - I am a fellow Violator brother also! how is your front upper turnbuckles, control arms and knuckles holding up?

Buku!!! You got a ticking time bomb. :sniper2: The only thing i have seen that junk work on is a LRP Z.28R!! I will PM you with a secret pipe for the K5.9motor that will give it a swift kick in the you know what!!!
 
Here is a COPY of a reply on rc universe forum. Props to OSLO for sharing this info!! Check it out and "Laugh" at this :duh:!!

---------------------------------------------------------------------
Unfortunately the BUKU pipe does not work on the K5.9.

I have used it on several engines with great results, but I ran into problems with the K5.9.
I contacted the owner Dave Masler, and below is a copy of his reply.

Hi,

Nice to hear from you, I'm glad all is well.

After quite a bit of prototype testing and dyno work I've concluded that
the current Buku is not compatible with the 5.9. The primary reason
lies in the operating pressure characteristics of the 5.9 motor. I'm
not exactly sure why but the motor fails to deliver much pressure at the
lowest rpm levels. (Virtually all of the other nitro motors I have
worked with produce a high initial pressure at the lower rpm levels and
this pressure falls off after the torque/power peak of the motor.) This
low initial pressure makes the operation of the pipe, as its currently
designed, not effective.

I have a few methods that I plan on trying to "correct" the movement of
the pipe but it will take more development then just a simple modification.

Depending on the outcome of my ongoing research I may be able to make a
replacement end-cap/convergent cone combination that will allow the
current pipe body to be used with the 5.9, but well see...

I have already completed some of the work, but I moved my production
facility over the winter (very time consuming) and also have a few other
pressing project that I'm working on as well. I'm hoping that I will be
able to complete the 5.9 pipe (or at least determine if it will be
feasible) in the next couple months. I'll be sure to keep in touch.

Best Regards,

Dave.
-----------------------------------------------------------------

O man, that came from the man that makes the pipes!! You cant get more truthful than that!!
 
Well I've emailed HPI about this trouble and I have been asked to send it back for repairs. It sounds like they are curious about this type of problem, here's hopin' that they can shed some light on it.
 
Gator they know its a flop they will replace it ask for a F4.6 when they do. Also ask for the HD 47 spur and racing 17 bell they will give it all to you no questions asked. The F will smoke the 5.9 any day of the week no need to worry. just tell them you don't want that flop...
 
I've taken out my 5.9 and sealed it up, everything from the Back plate to the Carb, I also did i small seal around the cooling head. It is now in peak running order, pulling wheelies and blowing off my buddies OFNA, heehee. Here's hoping that I actually fixed the problem. I appreciate all the advice, HPISF ROCKS!!!!

Gator
 
glad u got it all figured out, now the fun starts!! lol
 
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