I was given an RC and it needs some work. It needs cleaned up, and some new parts. I have no idea what model it is and all I know is that I believe it's an hpi. Are there any identifiable numbers any where on the frame? I am completely new to this hobby and any help identifying the model so I can find an owner's manual, order some new parts and get it running would be greatly appreciated. Thank you

HPI Nitro RS4 MT2, nice truck! Hope the motor isn't gummed up yet, it looks like its been sitting for a while.

Thanks for the quick response. It has been sitting for a couple of years. I plan on tearing it down and getting it all cleaned up and running. The air filter was gummed up pretty good. Looking over the owner's manual, it looks pretty in depth. Hopefully I'll have it up and running before too long. Thanks again

Collector is wrong, no other way to say it. This is a HPI Firestorm, not a MT2. Owners manual, exploded views, and parts list are available online in pdf form from HPI.

Btw acetone works great dissolving old nitro gum, but it might dissolve the foam air cleaner too. If the engine is gummy just pour some down the carb and threw the glow plug. Let it sit on one side for a few hours, turn the crank a little, let it sit on the other side. Pop the carb off and let it soak in a cup of acetone. Then just turn the crank with it upside down, glow plug out a few times. Then run it or spray some wd40 in it if it's going to sit for awhile before running. If you can help it you're better off not taking the engine apart anymore than this, the possibility of creating more headaches for yourself increases the more you take the engine apart unless you're going to seal it all up with rtv

Dawn dish soap works best on the foam air filter elements. Soak with soap, squish to distribute, let sit 5 min. Rinse, dry, oil, done.

Do NOT use WD40 to oil the engine. That stuff is snake oil if there ever was such a thing. Dexron Automotive trans fluid works very well, or even a good dose of Marine Fogging Oil will do the trick. WD40 is nasty stuff when it's left to set..

Quick, don't really agree on the snake oil part and I wouldn't use wd40 in a nitro engine normally. But I meant for it to be used to wash out the acetone and would assume the engine would be run within a few days so it would be fine. After run oil or your suggestions are much better for normal use and longer term storage.

Curious if you've tried ATF in a gummed up engine. It might not work as fast as acetone but considering the detergents in it ATF might work well in dissolving old gummy nitro fuel.

I meant to say to use acetone (which evaporates very quickly) to loosen the engine first, which will dissolve the oil left behind and removes it. Use a little ATF or air tool oil to re-lube the engine before running it so it's not getting run dry only after the acetone is evaporated (and the residues are dumped out or removed). If it's been put up more than a year or two, it should be at least have the backplate removed (should be done anyway to remove the crud the acetone knocks loose) to ensure the bearings aren't rusty.

WD40 is essentially naphtha (paint thinner) and a very light light oil. The problem with it is it will swell the silicone parts in the carb and cause leaks. Really, it's a very poor lubricant. It's good usage is water displacement. That's what WD stands for. ATF has much better lubricating qualities and doesn't seem to swell silicone parts.

Engines put up for long periods of time should be partially disassembled to make sure there aren't any nasty little surprises inside, so my advice is to soak it first to loosen it up, pop the head and backplate off, soak/rinse/clean again, and if bearings are okay and nothing else seems amiss, re-oil the main parts and reassemble. Rusty/gritty bearings can eat glow plugs and piston/liner fits very quickly, I'd not chance ruining the engine by not being thorough.

I used PB Blast on a traxxas .15 motor once....the motor was totally locked up, could not budge the flywheel at all. Took the top off and removed the pull start and let it sit in a bath of PB Blast over night. Next day put the motor back together and had it running and tuned in less than half an hour.