TTR EK4 S2 Project BEAST MODE

[twintec99]

Once it gets beyond that pinch point ,there is no way that it would run properly & tune!
If the piston /sleeve still looks good ,an is smooth ,you can send it in an have it re-pinched
for $ 20 bucks + $ 10 for shipping ,which is well worth it it!

Called redcat and they confirmed it should be 5mm from top of head. He said something probably caused rod to stretch when it locked. In that case, where can I get parts? They would not be able to repinch at this point if rod is stretched would they? I have been removed from RC so long, it's like starting over regarding finding who to call piston, sleeve and rod all look new. Thanks in advance.

 

[Nitrotrout]

I'm guessing those new parts you posted are no longer available?
I have the sliding set up on my V2. Even though the shoes are still in good shape, I'm going to make some out of clutch material I have.
I made this set out of phenolic. Didn't work. Too slippery.

Copo I agree, I don't think either clutch assembly is available these days, Thankfully, any big block 1/8 scale buggy clutch kit will fit.
I adapted a Buku adjustable clutch to my Pro .70 and it's held up to a 1/2 gallon of fuel with no noticeable problems thus far.

So after tearing the motor down because I just had to know if the motor was OK, I do have the revised clutch like yours. Not sure why my motor was stuck...bearing looked all gunked up. I baked it at 300 and got the piston up to 250. It came loose. I cleaned it up and used Mobil one to lube piston and crank. Did they come out with a better bearing that I should have before putting it all back together? I did not want to force the rod off.

I pulled on it with needle nose and it really was not cooperating. What is your method for getting rod off crankshaft.Maybe I needed to use more force. There did not seem to be any give like smaller engines have. So I hit pause. Motor spins fine now and piston looks brand new. Been sitting for 10 yrs though. So new bearing might be best while torn down. There is really nothing online about this motor.

twintec99 most likely its old fuel seizing up your engine. It turns to a glue like substance with age. Nothing a good soaking in nitro cleaner. or WD40, or the like wont cure. That is a sweet looking engine with all those MSJ goodies, BTW.
I use a zip tie looped behind the conrod and pulled outward to remove it from the crankshaft. The crankshaft pin / conrod should be at the bottom of the crankcase when you remove it Theres a good possibility old fuel is also preventing the conrod from detaching from the crankshaft pin. A little soaking and scrubbing should break it free.
Unless the cylinder is heavily scored, theres no need to replace it or the piston.. The.70 engines use a piston ring like a full scale engine.
http://www.ebay.com/itm/THUNDER-TIG...419956?hash=item43eaff78b4:g:rwwAAOSwF1dUSQzq
Chances are after sitting 10 years you'll probably need some new O rings for your carb such as these:
http://www.ebay.com/itm/NEW-Thunder...648745?hash=item1e9d7412a9:g:m3cAAOSwPgxVMpu3
Bearings
http://www.ebay.com/itm/Thunder-Tig...943976?hash=item25994ff4a8:g:vUcAAOSwIBBUZ7WU

 

[COPO]

What you all running for fuel? I'm using Cool power 30% nitro.

 

[twintec99]

Copo I agree, I don't think either clutch assembly is available these days, Thankfully, any big block 1/8 scale buggy clutch kit will fit.
I adapted a Buku adjustable clutch to my Pro .70 and it's held up to a 1/2 gallon of fuel with no noticeable problems thus far.



twintec99 most likely its old fuel seizing up your engine. It turns to a glue like substance with age. Nothing a good soaking in nitro cleaner. or WD40, or the like wont cure. That is a sweet looking engine with all those MSJ goodies, BTW.
I use a zip tie looped behind the conrod and pulled outward to remove it from the crankshaft. The crankshaft pin / conrod should be at the bottom of the crankcase when you remove it Theres a good possibility old fuel is also preventing the conrod from detaching from the crankshaft pin. A little soaking and scrubbing should break it free.
Unless the cylinder is heavily scored, theres no need to replace it or the piston.. The.70 engines use a piston ring like a full scale engine.
http://www.ebay.com/itm/THUNDER-TIG...419956?hash=item43eaff78b4:g:rwwAAOSwF1dUSQzq
Chances are after sitting 10 years you'll probably need some new O rings for your carb such as these:
http://www.ebay.com/itm/NEW-Thunder...648745?hash=item1e9d7412a9:g:m3cAAOSwPgxVMpu3
Bearings
http://www.ebay.com/itm/Thunder-Tig...943976?hash=item25994ff4a8:g:vUcAAOSwIBBUZ7WU

Thanks for all the links NT! I cleaned it up and it's rotating fine. Just as piston gets almost to the very top, I can feel a slight snag with motor back together. Maybe it's normal and just the ring as piston changes direction...not sure, but it all looks brand new regarding piston and sleeve. I got thinking about that comment of a stretched rod and piston being too high... I don't think so. I think it is normal position based on further inspection of msj tmaxx head compared to EK4. If you see pics I posted, tmaxx head has 5mm lip that sits inside tmaxx sleeve, therefor that piston would have to be recessed 5mm. The EK4 head is flat on top, just like the stock, thereby allowing piston to travel higher. Do you agree Nitrotrout (NT)?? What battery do you suggest for servos. Again, been a long time and any advice is greatly appreciated. Any other advice you have regarding stock chassis, tuning settings, warning what should be replaced if stock is no good, I am all ears. I included some photos. Not as cool as yours, but for 13 yrs old, pretty clean.

 

[cbaker65]

Doh...I didn't realize that was a ringed engine ,my bad!

 

[twintec99]

No worries. I would rather be on the safe side and prevent a problem, then just throw caution to the wind and not due any research. Thank you for your input.

 

[twintec99]

Will this charger work to charge 2 18650 3.7v 3000 mah Li-ion batteries, if the proper connections were made with the correct connector? That will create a nice light weight powerful 7.4v battery. I noticed the 6 v battery seems to struggle to turn those big tires.

http://www.ebay.com/itm/Battery-Cha...633579?hash=item2a314b20ab:g:VWwAAOxyXVBSMXR4

 

[cbaker65]

Will this charger work to charge 2 18650 3.7v 3000 mah Li-ion batteries, if the proper connections were made with the correct connector? That will create a nice light weight powerful 7.4v battery. I noticed the 6 v battery seems to struggle to turn those big tires.

http://www.ebay.com/itm/Battery-Cha...633579?hash=item2a314b20ab:g:VWwAAOxyXVBSMXR4

I don't see why not!
I use to make my own batteries as well.
One time I got my hands on some old video camcorder back in the early 90's ,
They were a aa 4400 mah ,I made receiver batts out of them ......LOL
They rarely needed charge!

 

[Rooky78]

Its been a few years now, but when I was researching a new charger, that B6 was well regarded.

 

[twintec99]

You mean this one....
http://www.ebay.com/itm/like/171716921603?lpid=82&chn=ps&ul_noapp=true

Thanks, I saw that one as well. Good price. Those Li-ion 18650's are cheap and have great power. I temp hooked two up to the EK4 and tested the steering. It really came to life. I'll use them on my FG1/5th scale too. It needs quite a bit of power to turn its steering as well. I have seen various duration from 3000 up to 9800. The 9800mah are super cheap, 2 for 5 bucks. Wonder if they use these in electric RC cars. That is quite the run time.

http://www.ebay.com/sch/i.html?_odk...800.TRS0&_nkw=lithium+ion+18650+9800&_sacat=0

 

[Rooky78]

No, I was talking about the original one you linked to. The Imax B6AC

 

[twintec99]

No, I was talking about the original one you linked to. The Imax B6AC

I see, I just noticed they both say B6 but different configuration. Thanks.

 

[Nitrotrout]

What you all running for fuel? I'm using Cool power 30% nitro.

@COPO I'm currently using VP Racing Fuels 20% oil 20% nitro helicopter fuel. . I'd like to use a 30% nitro fuel but none of the five or more rc hobby shops within a 20 mile radius of me offer such a fuel. I have to special order. LOL

The EK4 head is flat on top, just like the stock, thereby allowing piston to travel higher. Do you agree Nitrotrout (NT)?? What battery do you suggest for servos. Again, been a long time and any advice is greatly appreciated. Any other advice you have regarding stock chassis, tuning settings, warning what should be replaced if stock is no good, I am all ears. I included some photos. Not as cool as yours, but for 13 yrs old, pretty clean.

As I recall the piston did travel unusually high even with the fresh piston ring in it. I think I might have posted pics of it even.
As for servos, anything is better than stock, same goes for the AM transmitter/receiver.I'd suggest a high torque servo for steering to compensate for the oversized wheels and tires, a fast servo for throttle /braking, I prefer HiTec servos but there's several comparable servos on the market these days.

A 6v rechargeable humpback battery to power the servos is always a better choice than the 4 AA batteries.
As for chassis adjustment, the shocks are the weakest point IMO. !/8 scale buggy shocks would be a vast improvement as well as the shocks COPO used, or the Losi 8ight Shocks like I used.

 

[twintec99]

Thank you. I did get it running. once broken in. what settings on carb do you have? Obviously altitude and humidity is a factor. How many turns is your, high, mid, and low screws out out?

They sold me an LC4 Long reach plug and a Mccoy MC-59 hot plug, he stated the shorter hot plug would be easier to tune. It does die when removing glow plug igniter almost immediately. Is this common? Could it be a shorter plug causing this? They did suggest I use 20% nitro to be safer on the engine.

Rt now high speed is out 3 turns, Midrange is out 1.5, and low speed is out 3 turns, and idle is out about .5.

@COPO I'm currently using VP Racing Fuels 20% oil 20% nitro helicopter fuel. . I'd like to use a 30% nitro fuel but none of the five or more rc hobby shops within a 20 mile radius of me offer such a fuel. I have to special order. LOL



As I recall the piston did travel unusually high even with the fresh piston ring in it. I think I might have posted pics of it even.
As for servos, anything is better than stock, same goes for the AM transmitter/receiver.I'd suggest a high torque servo for steering to compensate for the oversized wheels and tires, a fast servo for throttle /braking, I prefer HiTec servos but there's several comparable servos on the market these days.

A 6v rechargeable humpback battery to power the servos is always a better choice than the 4 AA batteries.
As for chassis adjustment, the shocks are the weakest point IMO. !/8 scale buggy shocks would be a vast improvement as well as the shocks COPO used, or the Losi 8ight Shocks like I used.

That 8.4v Li-ion I made is just what those servos needed regarding steering. Not sure how long they will last yet, I just put the pack in. The 6 volt seemed way too weak.

 

[twintec99]

EK4 NO more. JK. I have to laugh even though I am super pissed. I have an RC dyno in which you can bench test and tune your engine. Not sure they are even made anymore. I ran 4 tanks of fuel through tuning engine. Radio worked perfect and voltage was fine. I take it to a grass field. The radio loses signal at about 75ft away warming up engine, throttle stuck at about 70%, it climbed a tree, lands, takes off and nails a fence. It bent front drive shaft badly, and broke the front rt lower control arm. It could have been much worse. Engine fired right up, radio worked fine again. Not sure what caused it, but now the whole front end probably needs a rebuild. &^%$^&**&^&

 

[cbaker65]

EK4 NO more. JK. I have to laugh even though I am super pissed. I have an RC dyno in which you can bench test and tune your engine. Not sure they are even made anymore. I ran 4 tanks of fuel through tuning engine. Radio worked perfect and voltage was fine. I take it to a grass field. The radio loses signal at about 75ft away warming up engine, throttle stuck at about 70%, it climbed a tree, lands, takes off and nails a fence. It bent front drive shaft badly, and broke the front rt lower control arm. It could have been much worse. Engine fired right up, radio worked fine again. Not sure what caused it, but now the whole front end probably needs a rebuild. &^%$^&**&^&

You got the old AM radio?
If you do ,wheres the antenna hang from the receiver?

Well I seen the pics ,an kind of seen the location.
Its not too good to have the antenna hang over the engine because it catches radio interference
from the clutch bell an any other moving parts.

 

[Rooky78]

Man, that's a drag. Time for a fail-safe.

 

[twintec99]

Antennae comes straight out of the box, right alongside the motor. That is an FM Futaba radio. Is that a 96 millimeter dog bone that I bent at the front tranny? Need to find correct part. Fail safe too....

Is that front skid plate supposed to be bent? It looks too perfect not to be. I just don't recall. It took a big hit.

 

[Nitrotrout]

EK4 NO more. JK. I have to laugh even though I am super pissed. I have an RC dyno in which you can bench test and tune your engine. Not sure they are even made anymore. I ran 4 tanks of fuel through tuning engine. Radio worked perfect and voltage was fine. I take it to a grass field. The radio loses signal at about 75ft away warming up engine, throttle stuck at about 70%, it climbed a tree, lands, takes off and nails a fence. It bent front drive shaft badly, and broke the front rt lower control arm. It could have been much worse. Engine fired right up, radio worked fine again. Not sure what caused it, but now the whole front end probably needs a rebuild. &^%$^&**&^&

Its Murphy's Law: RC's only lose signal at full throttle. Sorry to hear about your rig. Look on ebay for your parts first. If you can't find parts specific to EK4, look for
EB4 S2 suspension parts. They're identical. In the meantime ill try to dig up part numbers.

Antennae comes straight out of the box, right alongside the motor. That is an FM Futaba radio. Is that a 96 millimeter dog bone that I bent at the front tranny? Need to find correct part. Fail safe too....

View attachment 17810 View attachment 17811 View attachment 17812

Is that front skid plate supposed to be bent? It looks too perfect not to be. I just don't recall. It took a big hit.

The front of the chassis is supposed to have a slight bend like that.

 

[COPO]

I dug up some old info I had. This is how mine is set up. Damn can't get the bottom page on top. Lol. Read the bottom page first. I hope this helps.

Try this

EK4 NO more. JK. I have to laugh even though I am super pissed. I have an RC dyno in which you can bench test and tune your engine. Not sure they are even made anymore. I ran 4 tanks of fuel through tuning engine. Radio worked perfect and voltage was fine. I take it to a grass field. The radio loses signal at about 75ft away warming up engine, throttle stuck at about 70%, it climbed a tree, lands, takes off and nails a fence. It bent front drive shaft badly, and broke the front rt lower control arm. It could have been much worse. Engine fired right up, radio worked fine again. Not sure what caused it, but now the whole front end probably needs a rebuild. &^%$^&**&^&

Iv had the same problem with FM futaba radios. I have a spring attached to the servo horn that pulls the servo horn to close the throttle if the radio dies. Sorry about your wreck.
That dyno looks way cool. How does it work? More pics! I'd like to see how it works.
Thanks