Trying to understand what can I do now

[Madalin9184]

Hello!
I recently bough an HPI savage and currently in the break in process, as the weather was not good, I was not able to run it this week. Today's weather is ok and I wanted to start the car but when I pulled the starter, I was able to pull it easily as it was not engaging. I removed the engine and the Pull Start to clean out the one way bearing but when cleaning the axle on which the OWB is seated, I was able to move it freely. Pushing it slightly in make it work again without issues. I removed the backplate, cleaned all the oil that was on it and assembled it back, it worked for one pull and then it had the same symptoms. It is an engine problem? is it that axle broken? I only ran the car for 5 tanks. Has someone faced this issue? Thank you!

 

[fstnd]

There's a pin that engages, and it is pushed by a spring inside the crankshaft. Check if it's there, and if it is in good condition

 

[Madalin9184]

Oh, I understand now, taking a look. The store where I bought it gave me some instruction on how to break-in the engine and told me to not touch anything, and being my first nitro rc, I had lots of question and received minimal information. Thank you for the reply!

 

[Madalin9184]

Ok, it seems that the pin is not going out full? I can press is but it only goes out a tiny bit.

 

[Madalin9184]

found the problem..the spring is broken..ordered the replacement.

 

[fstnd]

That spring is very easy to lose.. also the first thing I ever had to order for my first savage. I've never seen one break though but it's great you found the problem

 

[CreepyQuarryCrawler]

Welcome to the site!

Nice set of opening posts and great job on the diagnostics

 

[Madalin9184]

Thank you!

 

[watertrucker]

Welcome to RCT. Nitro can be challenging but it’s great when you figure it out. That’s awesome you were able to diagnose your issue. Well done

 

[Madalin9184]

Thank you! You are all awesome!

 

[Madalin9184]

I have other questions that I didn't managed to find an answer that made my brain understand. As this is my first Nitro RC Car, I am well aware that the engine life will be short . Can I replace it with something similar? Do I need to find and buy the same engine? I found some engines at some the hobby stores in my country, but I haven't heard of the names ( Hobao .28 4.6cmc, and also an expensive one RB Concept Monster Truck 10 Pullstart .28 ).

Also, when giving the engine some acceleration, it seems that the RPMs slow down and then it shutdown, or it will try to keep going and then the car will move, is this something related to the settings being rich? or there is not enough fuel going in the engine?

 

[fstnd]

By the time your engine is worn out by use, you'll either have a whole collection to choose from, or you'll consider those approximate 46 hours of runtime per engine to be worth it that's a lot of tanks and they can probably take even more

 

[fstnd]

Also, when giving the engine some acceleration, it seems that the RPMs slow down and then it shutdown, or it will try to keep going and then the car will move, is this something related to the settings being rich? or there is not enough fuel going in the engine?

If there wasn't enough fuel getting to the engine, that's still a tuning issue. A video would help the most, anyways my best guess currently is that the high speed needle can be leaned out ⅛th of a turn at a time. Does your engine stutter while this happens?

 

[Madalin9184]

The only needle that I touched in this break-in process was the idle one, as the wheel were turning when the car was suspended. While reading the manual I noticed that it stated that the needles should be in the "factory setting" but the high speed needle is not, it was "screwed in a little". Will come back tomorrow with a video and photos. Thank you for your time and answers .

 

[watertrucker]

It’s amazing how long those tiny engines can last. I have a Revo 2.5R that is 21 years old and still runs like new. You just have to keep up with the maintenance. Also I like to run my engines a little rich, they run cooler and get plenty of lubrication that way.

 

[Madalin9184]

It’s amazing how long those tiny engines can last. I have a Revo 2.5R that is 21 years old and still runs like new. You just have to keep up with the maintenance. Also I like to run my engines a little rich, they run cooler and get plenty of lubrication that way.

Oh wow, that so awesome!!
That is my plan also, I don't need it to go fast, I just want to enjoy it's sound and bashing capabilities of the car.

 

[Madalin9184]

Hello ! Made the following video with the car after receiving a spring from a friends old engine, seems to have a little life untill my replacement spring and pin will come

(don't know why youtube decided to make it a short, but hopefully it's ok)
In the first part it's what I described that the engine dies after accelerating, was advised to turn a tiny bit to the right the LSN from the sliding carb and it should work, and yes now the engine works as it was before the spring incident. the rest of the video is how the engine reacts to the accelerator, seeing a lot of smoke and I understand that this is ok, as it is in the break-in process and it needs lots of lubrication. The next step now will be to run the car at 1/2 acceleration for some tanks. By any chance do you guys know what temp should the engine reach for this step? In the manual I only have what temps should I look out for when tuning the fuel mixture, and the hobby store did not gave me any information on this.

 

[CertifiedMike]

You should try to keep track of the temps at first so you know where your engine is happiest. A fair running temp range is 220-250F.

The 'factory tune' settings are a baseline. They are only a guide to get you running again if you've gone too far out of adjust.

Its 100% ok to adjust away from 'factory settings' to get your engine tuned correctly.

Adjust in small increments, 1/8th turn at a time and test.

Never store your RC with fuel in it.
For a day or 2, prob will be fine but fuel does go bad when exposed.
It will turn to gunk and cause no start or lock your motor up if left too long.

Are you using after run oil? If not, start now!

ALWAYS rotate your piston to BOTTOM dead center. ( piston at lowest point in crank rotation)
The metal expands as it gets hot. When it contracts as it cools, you want the piston down low where 'pinch' is less.
This will save the 'pinch' on your piston sleeve.

Clean and oil your air filter regularly.

I'm sure theres more I can't think of right now!


Welcome to RCTALK.COM!!!

 

[Madalin9184]

You should try to keep track of the temps at first so you know where your engine is happiest. A fair running temp range is 220-250F.

The 'factory tune' settings are a baseline. They are only a guide to get you running again if you've gone too far out of adjust.

Its 100% ok to adjust away from 'factory settings' to get your engine tuned correctly.

Adjust in small increments, 1/8th turn at a time and test.

Never store your RC with fuel in it.
For a day or 2, prob will be fine but fuel does go bad when exposed.
It will turn to gunk and cause no start or lock your motor up if left too long.

Are you using after run oil? If not, start now!

ALWAYS rotate your piston to BOTTOM dead center. ( piston at lowest point in crank rotation)
The metal expands as it gets hot. When it contracts as it cools, you want the piston down low where 'pinch' is less.
This will save the 'pinch' on your piston sleeve.

Clean and oil your air filter regularly.

I'm sure theres more I can't think of right now!


Welcome to RCTALK.COM!!!

Hello! Yes, I use after run oil, I have a 50ml bottle from Optiglobal, I usually take the glow plug out, put 2 drops, pull the starter 2-3 times, to be sure that the oil is betting everywhere and put the glow plug back.
The mentioned running temp is for after the engine break-in? or those are the temps that need to be during the process? Thank you!

 

[CertifiedMike]

Those are operating temps.

If you are following a break in procedure that requires monitoring temps, do that process as the procdure requires.

I would not try to start the engine while its cold. Use a heat gun to warm it prior to starting.

Its easy to find bottom of the piston stroke while the glow plug is out.
Don't forget this step!