GTRice

Do anyone have some problems with the carburetor on the K5.9? I had my Savage XL for a while now, it's been an awesome truck, but it's been a third time that the engine loss one of it's low speed needle. I'm not sure how the low speed needle came loose or fallen out, but I keep an eye on these needles, when running the truck anytime. I don't see the fact these needles needs adjustments like the high speed needle, just minor adjustments are necessary.

I sent the engine to HPI and I think they put a new low speed needle in it or something, but sooner within 3 months, it had fallen out on it's own. I sent it back to HPI second time and they replace the whole carburetor for me which helped a lot, since the low speed needle never had any problems. I was running the truck for two years with the newly replaced carburetor, no problems, until yesterday when I was running the truck, it shuts off, which the low speed needle was gone again. I kept an eye on this low speed needle and the whole carburetor and I don't know what happen. Do anyone have this kind of problem? What should I do now?

Argess

Never heard of that happening. Unless the o-ring is worn, the friction from it should keep the needle from moving. You might want to check the o-ring, although you probbaly lost the o-ring with the needle, and after 3 times, which I take it means 3 new o-rings, it's probably not the issue. BUt check your LSN anyway....it should not turn easily when you go to adjust it.

Is there something really out of balance that causes a lot of vibration?.....tires, loose engine mount, etc.?

Engine detonating? Lots of engine vibration when this happens. Might try richening your HSN a small amount.

GTRice

Not sure, if it's the o-ring, but it's still there. Yeah, before the LSN fallen out, it was kind of hard to turn for minor adjusting.

But I think your right about the vibrations. It may be the problem. When I accelerate the truck at high speeds, it tends to sway a little bit, I think it's the tires that was probably not glue probably at the factory. Also, I lean the engine a bit, which the engine does seems to make some vibrations. I lean the engine a bit, because I find that it easily shuts off, when it's riched. When I try to run it a little rich, which is most likely to happen is shut off, but it shouldn't happen to most engines, richening it a bit right? You still be able to run the truck a little rich.

sturb25

Easy Fix i had that problem with my O.S 30 VG but it was the idle screw. get some tread tape, wrap it round the tread in the opisite way that you screw it in. U will have to cut it to the correct width for your tread, go round twice. and you will never have a problem again.

Ive owned quite a few engines and its only happened to two of mine but when it starts happening it wont stop happening, its caused by oil getting on the oring

jeepster820

you could put some silicone sealent on the threads that also helps

Shenanigans

My Feedback: (12)

I dont think you want to tape, or silicone seal the threads of a needle that you will adjust frequently...idle screw maybe, MSN yes if you plan on keeping it in one spot.  Every time you turn the needle you risk getting some of the sealant or tape into the engine. 

I've never read of a problem like this before....read a lot on the MSN out of the k4.6 coming loose and backing out, but never the LSN.

GTRice

Thanks guys. Probably the oil in the oring is maybe causing the problem.

Yeah, I know this is a very unusual problem that anyone could ever have with their nitro engine. The K5.9 runs great, just that I never experience a problem like this before, when I ran many nitro vehicles in the past.

nitrotec

i did straight out of the box. after braking it in and after further inspection, i realized the carb was was defective. hpi sent me a new one for free. hpi is good this way.

Mclovin350z

You can very carefullybooger upone of the threads on the needle. Do this carefully on the back of the threads and it will turn a little harder. Don't do it on the very front of the threads (needle end) or it won't thread back into the carb slide. It doesn't take much but I've done it on other engines with great success.

GTRice

Mine was a defective carburetor too. But big thanks for HPI for replacing it with a new one before.