Kyosho KE.21R questions

[BenJammin]

Hi all, new member here.

I have a Kyosho Inferno MP9 TKI3 with the KE.21R engine. The buggy was purchased around 2017 and spent a few years sitting with no after run oil in it. When I dug it out a couple of years back, I had no issues getting it running - it basically fired straight up and has run well since. However, it makes an almost ear piercing metallic noise when you're near it. I've had the engine out and spun it over by hand to feel for bearing failure and it feels pretty smooth. Any ideas what could be causing the noise? I thought maybe it could be the pullstart shaft mechanism but I want to be sure before it destroys itself or something.

It also has a pretty burbly, rough sounding idle and spits lots of oil on tickover - pulls well at the top end and leaves a nice thin trail of smoke. Takes off well with no bogging, but smokes a lot on initial takeoff, and does bog a little if left to tickover for more than 10 seconds. Pinch test stalls at about 3-4 seconds (I'm aware the pinch test only gives a rough idea of the LSN tune). I'm thinking the LSN may be a little rich, but when I lean it out it starts to struggle on takeoff.

I can try to record a video of the noise but it's difficult to pick up on the phone due to the pitch of the noise.

Any advice is appreciated, thanks all.

 

[CertifiedMike]

Welcome to RCTALK.COM!!!
Before we talk about the motor I'd like to mention that KYOSHO RULES!!!

Now that we have that cleared up, the screaming sound is likely a clutch stuck or bad bearing in the pullstart.
Def do not run it until you have the noise worked out!!!
Get the noise worked out first. Then work on your tune.

Clearly, the best thing to do is box that car up and ship it to me so you'll have no more troubles!

 

[BenJammin]

Thanks for the warm welcome, CertifiedMike!

I'll get the engine back out when I'm off work - clutch bell spins freely but could there be something hidden? I've had the backplate off recently to change the pullstart plunger(?) O-ring, it has this style pullstart;

I didn't see any bearings, the drive plunger just sorta floats there on a cushion of magic and thin oil. My next question in that case; is the pullstart itself (the plastic portion) resposible for supporting it all when the plunger is pulled away from the crank? Is it possible that the recoil portion itself is just worn out and floppy?

Maybe I'm just not being particular enough about the way the crank bearings feel (I've not had much to do with glow engines) - it sat for so long (probably close to 5 years) with no after run oil I struggle to imagine there isn't any pitting or rust buildup, surely? It's difficult to see the balls (lol) past the crank.

You can't have my baby, she needs to keep my poorly T-Maxx company on the shelf while it waits for it's new heart. That's a whole story in itself haha. I need to fix one or the other, I don't wanna take the electric one out!

Thanks for the help, and sorry about all the questions!

 

[BenJammin]

Is it possible that the recoil portion itself is just worn out and floppy?

Ignore this - I'm being thick None of that assembly should spin at all once the engine has started and the plunger has disengaged, no?

 

[Littlemotor]

Ignore this - I'm being thick None of that assembly should spin at all once the engine has started and the plunger has disengaged, no?

Is this arrangement not the same as yours?

If not, it’s the first pullstart I’ve seen on a Kyosho without a one way bearing..

 

[CertifiedMike]

Thanks for the warm welcome, CertifiedMike!

I'll get the engine back out when I'm off work - clutch bell spins freely but could there be something hidden? I've had the backplate off recently to change the pullstart plunger(?) O-ring, it has this style pullstart;
View attachment 244198
I didn't see any bearings, the drive plunger just sorta floats there on a cushion of magic and thin oil. My next question in that case; is the pullstart itself (the plastic portion) resposible for supporting it all when the plunger is pulled away from the crank? Is it possible that the recoil portion itself is just worn out and floppy?

Maybe I'm just not being particular enough about the way the crank bearings feel (I've not had much to do with glow engines) - it sat for so long (probably close to 5 years) with no after run oil I struggle to imagine there isn't any pitting or rust buildup, surely? It's difficult to see the balls (lol) past the crank.

You can't have my baby, she needs to keep my poorly T-Maxx company on the shelf while it waits for it's new heart. That's a whole story in itself haha. I need to fix one or the other, I don't wanna take the electric one out!

Thanks for the help, and sorry about all the questions!

Listen, if I can't just HAVE your car, we've gotten off on the wrong foot. I gonna have to stop answering with good info and slide in some misinformation too.
I always wanted a job at the CDC.

We'll see how long it take ypu to get this started once I have you dipping your glowplugs in spray paint so you won't loose them when you drop them in the dirt!

Ok, so my theory is that something in the clutch setup is worn. The bell goes out of tollerance and the springs start hitting the clutch bell.
Might only start happening at higher RPM which could also be said of a dry bearing. Feels ok to spin by hand but is wonk when running.

Rust build up inside the clutchbell is common.

You should have a bearing on the pull start side as well.

https://nitrohobbies.com/kyo74031-10/

Like that maybe???


I feel like a tear down to inspect the parts after sitting for so long 'untreated' is pretty warranted.
Better than blowing up a motor at least.

I would replace the bearings anyways.

 

[BenJammin]

Is this arrangement not the same as yours?

No, mine has no one way bearing. There's a slotted drive that sits on the shaft of the plunger with a pin through it. As far as I can tell, when the engine starts the pin rides up the slot and pulls the plunger away from the crank. I implore you to enjoy my first MS Paint endeavour since I was, what, 11?

I will take some photos of it when I get a second to pull it off again, but without blowing too much smoke up my own behind I think that drawing is a pretty accurate representation lol. Just seems to me like it's gonna be a noisy setup, because there's nothing holding the plunger away from the crank pin, other than the force of the startup flinging the pin up the slot. I'd have thought it would work it's way back toward the crank with the vibrations

We'll see how long it take ypu to get this started once I have you dipping your glowplugs in spray paint so you won't loose them when you drop them in the dirt!

I was wondeering where all the pretty colours came from! I liked the pink ones, they match my eyes.

Thanks for the suggestions guys, at least I have some places to start looking. I may just try and find the engine bearing measurements and order a Reds clutch if I'm honest, no harm in a full refresh I suppose? Lol

 

[Littlemotor]

No, mine has no one way bearing. There's a slotted drive that sits on the shaft of the plunger with a pin through it. As far as I can tell, when the engine starts the pin rides up the slot and pulls the plunger away from the crank. I implore you to enjoy my first MS Paint endeavour since I was, what, 11? View attachment 244202

Psh! Well dammit done sir!!! Man-that’s crazy AF, learn something new everyday.. well if that’s the case-and the “magic” has worn off, then I’d be looking dead nuts at that heresy for your banshee scream..

 

[CertifiedMike]

No, mine has no one way bearing. There's a slotted drive that sits on the shaft of the plunger with a pin through it. As far as I can tell, when the engine starts the pin rides up the slot and pulls the plunger away from the crank. I implore you to enjoy my first MS Paint endeavour since I was, what, 11? View attachment 244202

I will take some photos of it when I get a second to pull it off again, but without blowing too much smoke up my own behind I think that drawing is a pretty accurate representation lol.


I was wondeering where all the pretty colours came from! I liked the pink ones, they match my eyes.

Thanks for the suggestions guys, at least I have some places to start looking. I may just try and find the engine bearing measurements and order a Reds clutch if I'm honest, no harm in a full refresh I suppose? Lol

I am not familiar with that plunger set up. I have seen a few ppl mention a weird 'kyosho pull starr' but never actually looked into what they mean. Def post up some pics!

You may very well have a noise coming from the thing that clearly needs a bearing that does not have a bearing!

A teardown to inspect is more than reasonable after this sort of time sitting.

I tyink it would be a total waste of you time and you should put it in the postage paid box that I just sent to your house.
( more misinformation)
and yes, those glowplugs match your pink eyes nicely!!!

 

[BenJammin]

I'll get it all apart tomorrow on my lunch break. The more I think about it the more it stands to reason that the plunger smashing against the crank pin thousands of times a minute is probably the noise I'm hearing. It's 'that' kinda noise if you get what I mean. Annoyingly it's an incredibly difficult nosie to both explain and capture

I am not familiar with that plunger set up. I have seen a few ppl mention a weird 'kyosho pull starr' but never actually looked into what they mean. Def post up some pics!

You may very well have a noise coming from the thing that clearly needs a bearing that does not have a bearing!

I never really thought much of it to be honest. Not until 30 minutes ago anyway I'll get some pics posted on this thread tomorrow.

Is it possible that it's something to do with it being an RTR buggy as opposed to a kit? Everything for the KE.21R has been discontinued so I can't even find a photo of it. The KE.25 pullstart mech looks a totally different design - I imagine the pullstart is one of the KE.25's many improvements over whatever the hell I have here haha. Maybe they even splashed out on a one-way bearing?

Thanks again both for all the suggestions. Shall tear it all down again tomorrow and give everything a good once over.

 

[Littlemotor]

I'll get it all apart tomorrow on my lunch break. The more I think about it the more it stands to reason that the plunger smashing against the crank pin thousands of times a minute is probably the noise I'm hearing. It's 'that' kinda noise if you get what I mean. Annoyingly it's an incredibly difficult nosie to both explain and capture

I never really thought much of it to be honest. Not until 30 minutes ago anyway I'll get some pics posted on this thread tomorrow.

Is it possible that it's something to do with it being an RTR buggy as opposed to a kit? Everything for the KE.21R has been discontinued so I can't even find a photo of it. The KE.25 pullstart mech looks a totally different design - I imagine the pullstart is one of the KE.25's many improvements over whatever the hell I have here haha. Maybe they even splashed out on a one-way bearing?

Thanks again both for all the suggestions. Shall tear it all down again tomorrow and give everything a good once over.

It’s definitely not something you’d experience with the kit version. No pullstart/RTR engine to fool around with. You’re correct about that.

 

[BenJammin]

Okay, I know it's been a year since I said I'd get some pictures, but, I now have some pictures!

If you look at the closeup picture you can see the seat of the drive adapter has been peened over from impact - I suspect this has been and will be my noise (at least until I get a bump box, and possibly an engine full of nice, shiny newness)

 

[BenJammin]

Also signs of continuous impact on the plunger.

Is this the wierd Kyosho pullstart you mentioned?