mousecritter

My Feedback: (3)

I should be receiving my Savage X SS soon and I wanted to know if that HTL issue has been fixed by HPI. It doesn't seem like there are many recent threads about the issue, so maybe HPI fixed it?

I've read that shortening the fuel and pressure line will help w/ the issue. This will be my first complete nitro experience with the whole break-in process, etc., so should I break-in the engine with short lines? Or should I first fire up the engine w/ stock length lines to see if the k4.6 has the HTL issue?

Mattholew

I'm sure your probably aware, but in case your not, you should seal your engine as well.

http://www.youtube.com/watch?v=6xwDy-I0Z4I

del1969

First off, leave everything like it is, untill you get some experiance.
Break-in like the manual says.

The htl issue is easy to solve, when you tune your truck after break-in use only half a tank of fuel.
After you tune it fill the tank up, this pervents the motor getting to hot at half a tank, but it will be a little
rich when you first fill it up.

You can also do this, fill the tank up and tune it, if the motor is leaning out at half a tank richen it up abit. just remenber, to lean it out the same amount
when you fill it back up.

BudBud

Man, that seems a little crazy. They have not fixed the issue and the polished pipe seems to be the worst. Shortening the fuel line seems to help as much as anything I have tried. It is a mod that will only cost you about three dollars if you do not like it. Normally, I just come back in for fuel when I hear the lean condition starting or see the tank getting below that step. We call it a half tank lean, but I think 1/4 tank lean is more like it. The lower half of the tank does not have nearly as much volume as the top does due to that step in the tank. Glen

SLAYERDUDE

I haven't tried the shortened lines yet.
I pretty much do what BUDBUD said.
When it starts to lean out, just bring the truck in leave it running and top it off.
I do normally set my final tune about 1/2 tank.

I know a guy that did a tee in the line with a check valve thing...
Big pain in the ***** and far from free but he said it works awesome.
I'll try to find the link and post.


SLAYER

TAKZILLA

I have wondered if any one has tried RBInnovations Hyper Valve or Offna makes a simular check valve that goes inline on the exhaust line,in theory maintains pressure on the tank.can't find it right now but offna calls it CPV constant pressure valve or something like that.
Any one know any thing about these?

mousecritter

My Feedback: (3)

Thanks everyone for the info. This problem sounds like a pain in the rear.

sparky 25

To be honest, after i shortened the fuel lines i never had the half tank lean problem with the k4.6 on my xss kit,

but once i fitted the lrp30 i started having the half tank lean problem,

don`t know how or why,

with the k4.6 engine it would keep the tune the whole way through a tank of fuel[sm=confused.gif]

sparky 25

Takzilla, i have run the check valve on my cen gst as it had terrible half tank lean,

after fitting the check valve it would empty the tank every time,

tuning with that extra pressure going to the tank meant that i had to run the engine much leaner or it would not run so good,

i ended up having to rebuild that engine twice in such a short period, even with average temps of about 220f

so now i just refill my trucks when they become half full.

TAKZILLA

Yes,thanx for the info.that's why I've never bought one.if it worked as good as it should everybody would be useing them.
I do wonder why other than you I get no input,good or bad?

Mattholew

Does the mid tank mod take care of the HTL problem? I am tired of having to refill after only a few minutes of running or having to stop and richen up as it burns down. I would love to solve this problem for good.

Argess

There are a few things going on that contribute to 1/2 tank lean, and ccertianly some engines are less susceptible than others. The check-valve idea is here:

http://www.rcuniverse.com/forum/m_74...tm.htm#7499609

I've been runing with the check-valve for almost 1.5 years and it's great. Engine runs same with a full tank as with an empty tank (well, you need some fuel...LOL). When it runs out of fuel, it's usually a surprise, except you sometimes get a light indication due to a few air-bubbles in the line as the tank finally empties.

It's much less of a pain to do than any of the tank re-location/replacement mods. Probably about the same cost as the Yamada valve is close to $10

B_YBASHER

change your fuel tank toofna 125cc #30280 that would fix your htl problem...i think lol...but you'll have shorter running time tho...

aci155

Had the same prob.. i took it to my local hobby shop and it tuned it for me but i still had a bit of a prob...i made the high speed needle a bit 2/8 of a turn leaner and it was fine its a beast:P  lo0l its even more economic on fuel:P

SLAYERDUDE

[sm=spinnyeyes.gif] So you leaned it out 1/4 to get rid of the lean problem...[sm=idea.gif]

Psst... 2/8 = 1/4 fyi