Newb with a Redcat Caldera engine troubles

[Silhyboy]

Howdy folks,

I picked this up on ebay with the knowledge that it had engine problems to begin with. When I got it, i found that the previous owner had opened up all the idle and mixture screws so everything was completely un-calibrated. I was wondering if anyone knew of the factory settings on a SH18 engine and also (heres the newb question) can I just replace it with another .18 engineor does it have to be an SH18?

I tried to take the head off to see what condition the piston and sleeve were in, but i don't have a full set of tools to do so. They are on the shopping list.

Any help or direction anyone wants to provide would be appreciated.

Cheers!
Silhyboy

 

[Rolex]

There are basic starting points that apply to almost all of these engines.
If all else fails, we'll let you know what kind of engines you can try.

Go through the following link to see if you can get your running and keep us updated on your progress so we can keep you advised as to what to try next. Just make sure your batteries are ALL new or fully charged and you have fresh fuel.

https://www.rcnitrotalk.com/forum/showthread.php?t=60832

 

[Silhyboy]

Thanks, i will be posting as I go along to keep whomever gurus up to date on my progress.

So, todays project is to see if the engine is startable... Nope. No pull start, and the drill start plate the previous owner sent with isn't the right size... So, bought the right one (i hope) from amazon since my local hobby shop doesn't carry these engines or parts for them. Next update will be friday when it arrives and I can put it all back together and see what I actually have.

 

[Rolex]

Got compression?

 

[Silhyboy]

Yes, when I turn the flywheel with the glowplug in, it goes through TDC and gets easier to turn. Also, i can feel air movement out of the exhaust fluctuating with the rotation. I would assume that this indicates compression in the piston chamber.

I haven't been able to try in earnest yet as I haven't had the appropriate parts in place to even attempt to start it.

 

[Silhyboy]

Pull start and tools arrived today. I attached the pull start and adjusted the throttle linkage so i had 1mm showing in the carb throat. Turned idle screw till it was 2mm or so down from the collar. Same with the high idle. Put it all together and added 20% fuel. Tried to prime it, but there was no pressure from the muffler to push fuel out. I disconnected it from the muffler and blew through the line to get fuel into the system. Tried a few pulls after reconnecting but still didn't see much fuel movement. Adjusted idle screw to see if mixture or flow was impeded. Somehow got right settings as it started and took off. Got it back and it stalled. Restarted, adjusted idle screws again to get proper mixture to sit at idle. Got it close, but clutch still engaged slightly (car crawled forward at idle). Figured it needed some warmup. So ran at low speed for 10 minutes. It kept stalling a little bit after throttle was released. Obviously needed more fuel flow.

Ended session after i ran into something a little harder than i wanted to and vacuum locked fuel system (air bubbles in line not moving). And couldn't get it running again.

So at end of day,
1. It starts
2. Idles high, engaging transmission
3. Doesn't have good vacume/air movement in fuel system.

I will be searching the forums later on to see if i can find some answers, but if anyone has other suggestions, feel free to post.

 

[Rolex]

Check all your fuel lines for leaks. That includes a good seal at the manifold and a good seal on the tank lid.

 

[Silhyboy]

Possible... Any quick fixes or should i go find a new line?

Is there supposed to be a clip or something on the fuel line where it attaches to the flares?

 

[Silhyboy]

Didn't find any leaks, but trimmed off last 1/8 of each connection to have clean tight tube to start with. Now drawing well, but after a bump, the line gets many air bubbles. I checked the seal on the gas tank thinking it might be unsealing, and at the same time realized that the draw is from the bottom of tank. Next culprit would be the fuel inlet on the carb. I can't see any cracks or obvious signs (wet spots, discoloration in the area) any other thoughts?

Also found your flowchart on tuning and troubleshooting. Will try to use that tomorrow. Been running the engine in 3-5 minute mid throttle runs since it dies at full throttle and just seems to not want to run more than 5 minutes and after is a pain to start.

Found out that needle settings need to be done with carb fully closed, should help eliminate some other problems i have been facing.

Overall, it appears that this is a new engine that the previous owner had zero working knowledge about internal combustion. So... Been taking it slow and trying to breakin slowly as well as tune it so at least it runs smoothly.

 

[Rolex]

Well, it's running. Congrats on that. Now it's just a matter of getting it tuned.
Since it will run at lower speed well start there. Get it started and warmed up. A quick hit on the trigger should launch it. If it sputters, hesitates or stalls you'll need to fine tune the LSN. Just turn it a little at a time, run it till it settles in...about 15 seconds...then stop it and launch it again. If it's worse, turn it the other way. Better, turn in the direction you were going.
You might also have to adjust the idle speed since it's affected by the LSN setting.
When it idles nicely and takes off from a dead stop, continue to hold throttle.
When it gets up to speed and starts to sputter, you'll have to make the adjustments on the HSN.
Keep us posted.