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Getting back into the hobby

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hornet7288

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Hello all!

Just about 10 years ago at the age of 15 or so I purchased my first nitro RC car...a duratraxx maximum ST with those ugly yellow wheels. I drove it for years and years until I went off to college. While in college I had no money to keep driving it so away it went for years. Now that i'm a few years out of college and have a job I have found myself wanting to get back into the nitro RC car world. While I realize the maximum ST is kind of a starter truck I would like to get it running again.

I noticed that the engine was seized so where should I go from here? I imagine I could rebuild it but I have little experience with pulling apart nitro engines. Does a nitro engine "rebuild" consist more of a tear down, clean up and re assemble or are there various parts that should be replaced?

Is it even worth rebuilding the motor considering it has been sitting for 7+ years seized up? If not, it seems that torq .12 engines are not readily available online. Are there other direct replacement (possibly larger) engines that will drop right in the place of my torq .12?

I have noticed that a good number of the maximum ST replacement parts are now obselete. Are other parts similar to the stock maximum ST parts so that they can be replaced as they break/wear out?

Another random thing. I know that years ago they sold a 2 speed transmission kit for the maximum ST. I never bit on this item because I didn't have the money then. I doubt they still make this not, but are there 2 speed kits available for my current engine configuration (or a replacement engine configuration) that will work with the maximum ST?

Thanks for the help and I really look forward to getting back into the hobby!
 
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hornet7288 said:
Hello all!

Does a nitro engine "rebuild" consist more of a tear down, clean up and re assemble or are there various parts that should be replaced?

I have noticed that a good number of the maximum ST replacement parts are now obselete. Are other parts similar to the stock maximum ST parts so that they can be replaced as they break/wear out?
Click to expand...

Chances are you just need to give your engine internals a thorough cleaning.
You probably have a collection of old fuel which turns to goo over time, and possibly some rust.
If you have a lot of mileage on your engine, then you should consider a rebuild. Rebuild usually consists of new piston and sleeve, bearings and seals.

HPI Nitro Star and OS Engines still offer small block, side exhaust, rotary carb engines for applications such as yours if you ever decide to upgrade.

As far as replacement parts go, I found that ebay is the best bet for finding discontinued parts.
 
I would feel comfortable with rebuilding it as I have a 89 toyota supra that I built the engine from the block up.

Where would I be able to find torque specs and whatnot for the motor?

Also I would like different exhaust. The exhaust the engine has on it now has a blue rubber exhaust pipe which breaks down over time and needs to be replaced often.

Where would I be able to find rebuild parts? Is the piston and sleeve simply a certain size just because the engine is a .12?

I don't know what is considered alot of use but I feel like the engine still has some life so cleaning may be my best option for now.
 
Thanks!

I am really excited about getting back into it.

I think tearing the engine down and cleaning it will be fun.

It has been so long that I can't remember much about glow plugs. What kind of glow plugs are good to run in a torq .12 engine?

And also if anybody has pointers on torquing parts of the engines back together that would be helpful. Are the gaskets reuseable or should they be replaced?

I need to get the mount screws out from the bottom. Two of them are stripped badly so i'll have to use vice grips to remove them.
 
Once your engine un-seized , turn the flywheel counterclockwise by hand.
You should feel resistance when the piston reaches top dead center. If you don't, chances are the piston and sleeve are worn.
Improper break in procedure, dirt into the engine, or excessive lean mixture can lead to premature engine wear and require rebuild. If your engine was properly tuned and maintained, you should get several gallons through your engine before rebuild is required.

Small blocks usually run best on hot glow plugs. OS Engines A3, Novarossi #4 or #5, McCoy MC59, are a few example plugs that would work with your engine.

Engine screws don't need to be torqued, just tightened snug with a dab of blue Loctite.
When tightening cooling head screws, tighten in a star pattern similar to lug nuts on an automobile. I also mark the cooling head and crankcase with a Sharpie so I can line the cooling head up the same way it came off.

The cooling head should have some copper shims which mate to the top of the piston cylinder. These can be reused. The exhaust header usually has a gasket which mates to the crankcase. Its a good idea to replace this gasket as they tend to deteriorate from heat, over time.

On a final note, if you remove your piston/ con rod, be sure the tiny oil hole in the con rod (above the con rod journal) is facing forward toward the flywheel during reassembly.

The carb and engine backplates are sealed with rubber O rings which should be inspected for cracks, breaks or nicks.
 
Sounds great! I appreciate the replies/help. I plan to remove the engine and attempt to clean it out in the next few weeks.
 
Wow.....I still have a maximum. No brake disc on it, but it runs. Almost forgot about the lil thing.
 
A couple summers ago I bought a control line plane at a flea market. It had an ancient McCoy .19 engine that was seized up tight. I just took the glow plug out, oiled it, broke it free, oiled it some more and it fired right up with a new glow plug. Your engine should live again!
 
That's what I'm hoping. I really feel like it doesn't have too much use on it.

If I can get it running again the only things I want to do for now are get a better air filter for it and maybe different exhaust. I mentioned before the exhaust is in the shape of a cylinder and has a blue rubber type pipe coming out of the back. I seem to remember having to replace these rubber pipes often as they were always melting a breaking off.
 
Well I got the engine removed and got it unseized just by using some oil and good ole fashioned elbow grease. The engine turns over well now and seems to have good compression at TDC. A few things before I put it back on, buy fuel and try to fire it up...

-I would like to get a better air filter than the one that came on the motor. I don't know anything about filters so where would I find one that would fit directly on a torq .12 motor?

-While cleaning the engine off some I noticed there was no exhaust gasket. Do I need one or could I go without for now? AND I would like put different exhaust on...same with the air filter. What kind of exhaust could I buy that would bolt directly onto the torq .12 motor?


Thanks

Pics of the motor

photo_zps4d4bf89e.webp
 
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What is a good rechargeable igniter? I have been looking for a decent one on amazon. Can't find my old igniter.
 
Sounds good. I'll snag both of those...any suggestions for a different exhaust setup?
 
Well I am about ready to reassemble everything. I am going to order a set of one of the glow plugs mentioned a few posts ago. Now the question is what is a good type of fuel for a small block nitro engine? Back when I used to drive it I would just buy whatever the hobby store had but I can't remember anything about it and whether or not nitro fuel comes in different blends.
 
Usually a good 20% nitro is all you need for bashing. I prefer Sidewinder and have had good luck with it. Other good brands that are discussed here are O'Donnell's and VP. Also support your local hobby shop (lhs). They are there to help.
 
I use Byrons. It just seems the best for me. Has a unique smell I like too! My nitros seem to really hold a better tune on it than any other. The price is good also.
 
Awesome. Some fuel and glow plugs are next on my list along with some air filter oil. Hopefully the engine even runs.

Unfortunately (to my knowledge) there are no hobby shops here in Savannah, Georgia. I've searched online and asked around as nobody knows of anything. If anyone on here is aware of a hobby shop in my area let me know!
 

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