having issue with tuning (i think?)

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D3MON

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Missoula MT
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  1. Bashing
so i have a AE .21R PRO, and am having some difficulties getting it running correctly.
first start of the day it fires right up, little prime, glow driver install, drill to activate spin start and she fires in just a few seconds of spinning.
then i let it sit idling for about 45 seconds to a minute with the igniter on.
runs pretty well (am still trying to tune it in).
getting blue smoke coming out the exhaust, have been able to tune it to where it sounds good on full speed passes, started very rich and slowly leaning it out to temp, one symptom is after a full speed pass then turn it around in the street to face the other way, it usually bogs out a bit if you pull WOT quickly, slower application it pulls strong.
also after WOT run it does hang idle a bit.
it revs up very well with good power after i do a series of short throttle pulsing, just running small circles/donuts and/or low speed pass.
at that point i start leaning out the MSN (its about a half tank in by the time i get here).
about this time it is 190-200F but its semi prone to stalling and i can't get it to fire back up.
only have about an hour after work so about 20-30 minutes of trying to get it fired back up i have to bring it in.
to me I'm thinking it would be a very rich MSN. but the fact i can't get it started afterwards is really confusing me.
I've tried starting it right away w/o priming, with priming. just spins and spins.
Disclaimer:
it is an older motor that is secondhand to myself.
Compression isn't the best, but it is there.
i have replaced all the o-rings in the carb, sealed the backplace, started from factory needle specs countless times, glow plug is good (i am running and O.S.#8) would it be an issue that it isnt a long plug?
fuel tank is sealed, all new fuel lines.
am i doing something wrong with tuning? missing something? or could it just be a worn out motor?

I've tried googling the symptoms, but the corrections from people with semi similar issues don't seem to be working on mine, the only one i havent done yet is replace the piston/sleeve, which i have one ordered but just keeps seeming to me there is enough compression it should still have a little life left in it.

Thank you in advance for any help.
don't normally like to post tuning questions as there are already so many out there but this one is confusing me.
 
I don't know what's a MSN, there are a LSN and a HSN. I'm guessing you are having a problem with LSN, try to lean it a little bit.
 
I don't know what's a MSN, there are a LSN and a HSN. I'm guessing you are having a problem with LSN, try to lean it a little bit.
Oops yeah meant lsn, not msn, Been trying to slowly, (from factory settings). But once it stalls out can't get it fired back up.
 
I don't know what's a MSN, there are a LSN and a HSN. I'm guessing you are having a problem with LSN, try to lean it a little bit.
Also msn=mid speed needle, this doesn't have one, but enough reading on tuning issues brain gets a bit googly lol
 
What you’re describing sounds more like a worn piston and sleeve than a tuning issue. The sleeve expands with heat and compression decreases. A new piston and sleeve will probably solve your problem. Just remember to break it in again with the new parts.
 
What you’re describing sounds more like a worn piston and sleeve than a tuning issue. The sleeve expands with heat and compression decreases. A new piston and sleeve will probably solve your problem. Just remember to break it in again with the new parts.
Ok thank you, just waiting for the piston to come in the mail. Have never worn out an engine yet lol.
 
Also you should heck the front bearing for leaks, if it's worn out it will lean even more the mixture air/fuel. This happened to one of my engines, although the piston/sleeve were OK
 
Also you should heck the front bearing for leaks, if it's worn out it will lean even more the mixture air/fuel. This happened to one of my engines, although the piston/sleeve were OK
will have to check that, i ordered a new crankcase, backplate, and bearings for the new piston and sleeve when it comes in, didn't know if the issues i was having was tuning.
thanks for all the help!
 
You should have checked the entire motor before ordering any parts. If you'll change everything you'll end up paying more than a new motor
 
i do understand that it can be quite expensive to rebuild engines but the build i am doing for this, it is worth it to me to have it back to original, that said though, I've been super lucky to find all the parts i am ordering either on clearance or a really good price.
so far i am in it for:
40$ for new piston/sleeve
12$ crankcase
8$ backplate
10$ conn rod
12$ bearings
4$ carb o-ring set
Total of: $86

I do appreciate the advice though, but the nature of what i am trying to do it is worth it to me to spend a bit extra, even though so far i feel that I am still under a new engine cost and almost all new engine, and almost impossibility of finding a new/almost new AE .21R PRO engine, and almost all parts new except for crank (having a hard time finding one but still appears to be in good shape).
 
Well, you may have been able to send the piston/sleeve somewhere to get it repinched. That usually will get a few more gallons of life out of it at least. I've had engines do what your experiencing and it was due to loss of compression when hot. Would flame out for no reason, but run ok otherwise. rayaracing.com used to do it as did osrocket. Not sure if they are still around though.

I had rayaracing do mine a long time ago:
https://www.rctalk.com/forum/threads/had-a-few-sleeves-serviced-by-rayaracing-photo-intensive.56420/
 
thats too funny!!! saw one of your posts a few hours ago where you were telling someone to get it re-pinched by them! i was planning on sending in my HPI .25 and the AE .21 sent to them anyways have some back ups. then eventually can swap in the .25 when the second .21 burns out.
i was checking out their site anyway, havent tried contacting them if they still are in the business.
it seems he does great work, and at least his website shows some amazing results as well.

Thank you! and thank you for your previous post lol!
figuring if i have a spare piston/sleeve at all times then when i send it off to get re-pinched i can still be running as I'm waiting for them!
 
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