Feels like I'm just solving one issue after another with nitro!

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Same design?

The design of the brake actuating rod is the same but not the transmission housing. That's why I swapped over. The stock is plastic and the top is covered, preventing easy access to the shift point adjustment screw.
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Okay, so typically the actuating rod is being held by the piston that pushes out when it's rotated. The rod has a notch. If it's falling out it means you've got it articulating too much. Brakes need to be tighter, and the travel of the linkage less.
 
Took two months to get the thing to the point it was starting, and running reliably.

Several weeks to get it to even start, then after that it was a whole saga to get it tuned.

Then several weeks to get it to shift into second gear. It kept shedding the clutch adjustment screw. Then when I fixed that issue from happening and it was finally reliably shifting into second gear. Then the tires were worn and it wouldn't grip so I replaced those. Then I bent a prop shaft.

Then after I fixed that with beefier shafts the ceramic brake disk got worn completely round so that even with the brake disk locked the c cup could still spin freely.

I've just fixed that with a metal brake disk and now I'm wondering what is the next issue that will reveal itself?! I get round one road block and then there's another massive one.

I've noticed the revs starting to fluctuate just before gear change so I'm guessing some issue related to that will suddenly reveal itself next. 😑


Just once I'd like a session to end when I'm finished driving, not when the car breaks!

Is this the normal nitro experience?
Hi there it sounds like you have fixed a lot of issues with that Rc. May i ask what brand is it.
 
Took the car out for a bash today. Guess what failed after 5 minutes?

If you said the brake actuator shifting up, dislodging the piston so the brakes fail. You were correct!

This will be the 6th time I've have had to fix this issue!!

The design is so bad! Not only how it keeps happening. But how you need to take the engine and transmission out to fix it.
Hi there it sounds like you have fixed a lot of issues with that Rc. May i ask what brand is it.
HSP. Don't buy one. I've had nothing but issues from day one
 
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Finally had a session where nothing went wrong. And I was able to drive until I was finished. Instead of when the car broke.

Doesn't seem to shift reliably into second gear. But it's a cheap car.

Usually takes about 5 minutes of running before it will shift. And then it shifts well but after about 10 minutes of running it will start failing to shift and I need to let the engine cool. I'm not sure what's going on there.

I thought shifting was a function of engine revs.
 
Not sure, misplaced the temp gun recently. Can't go any more rich though or it doesn't rev high enough.
Are you running so rich, that the car engine is just too cold and not reving up high enough to shift into second gear?
Then when you stop, engine loads up on too much fuel and again has issues shifting once you start to accelarate.
There is not reason for tranny not to work, if its shifting its shifting. Its quite simple in design.
You need to lean that engine out a bit.
 
Are you running so rich, that the car engine is just too cold and not reving up high enough to shift into second gear?
Then when you stop, engine loads up on too much fuel and again has issues shifting once you start to accelarate.
There is not reason for tranny not to work, if its shifting its shifting. Its quite simple in design.
You need to lean that engine out a bit.

No it isn't really like that. I start the car and drive it. And it won't shift for about 5 minutes. After that time has passed the car will start shifting well.
Then about 10 minutes of hard driving the shifting becomes intermittent, if it does shift, revs start to flutter up and down before it shifts.

After a few minutes of that it stops shifting.
 
It could be that the clutch inside the 2 speed cover is getting hot or worn. It is good to take a look.
 
Took the car out for a bash today. Guess what failed after 5 minutes?

If you said the brake actuator shifting up, dislodging the piston so the brakes fail. You were correct!

This will be the 6th time I've have had to fix this issue!!

The design is so bad! Not only how it keeps happening. But how you need to take the engine and transmission out to fix it.

HSP. Don't buy one. I've had nothing but issues from day one
At this point, I would start buying HPI Nitro Rs4 3 evo parts. Make sure its a 2 speed shafty. I was considering HSP parts before I found an HPI plug.

The Nitro Rs4 was the car they cloned.
 
I have been after one of these HSP race 2 speed versions for a while, few came up but were not priced right for me.
I was gonna make it my go to racer, and give the RS4's a break.
Will report back when I get one, but as I said from my experience they are tough cars, not sure how you ended up with a dud.

Install your original tranny back and see how it goes then...
 
I can see where you're coming from with HSP's teething issues, but I really love what they did with parts commonality across their lineup - I've bought one of each of their 1/10th nitros, the onroad, buggy, SCT, rally car, and Monster truck, 5 in total. I think their issues aren't of design, but of build quality

Some issues they all shared, like the exhaust gaskets blowing out, some were random from differing build qualities. I think solving them all such that they didn't reoccur was a great teaching experience that made me very aware of the concepts and construction of a nitro-RC in general, which translated over very well to a nicer model when I finally got one. Unboxing a Kyosho felt like opening a present, and breaking it in was like experiencing the service at a fancy restaurant for the first time.

I think the stock transmission would do a lot better for you than the aluminum one. With a bit of loctite the setscrew in the clutch won't back out. The plastic second-speed gear has a metal pin pressed into it for the clutch to grab, but sometimes replacement transmissions are sold without it and the metal clutch pawl eats through the plastic gear after just a few gear changes, which is why you get the problem where it won't shift into second. The metal second speed gear might solve this problem entirely, but introduces new ones.
 
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