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-   -   Ofna Force .21 JL (https://www.rctech.net/forum/offroad-nitro-engine-forum/345765-ofna-force-21-jl.html)

reggie l. 04-28-2010 04:18 PM

temp guns just create problems.. i dont even use mine at all, long as there is blue smoke and you dont hear lean sounds etc.. your fine...tune by sound and feel

easyryder 04-28-2010 05:01 PM


Originally Posted by lsbully (Post 7332150)
NitroFreakManHo-

Clutch and bearings are all new, it does make a blubbering sound when I hit the throttle and then dies. It does not idle down very fast after WOT either!



Maximo-
Engine is stock

Tons of Pinch

Byrons 20%

The first 8 tanks I did small circles at half throttle, then started leaning it out.
I have a 1/4 acre area near my house the I run the car on, a few sharp turns and a few bumps here and there, to similate some what of a track environment.

I was wondering the same thing you mentioned about pulling one shim to see if it helps out any.

Re- set low needle to 4 full turns out from fully closed, top needle 3 1/2 from fully closed, the bottom needle on these does not need to much tweaking, make sure the idle gap is 1-2mm max too wide will throw everything off. be sure to have the radio on when checking gap as well, you might need to close up trim or adjust linkage. You may want to try an os p3 plug.
Hope this helps some:cool:

CKmaxx 04-28-2010 05:16 PM


Originally Posted by Maximo (Post 7331829)
....temps are meaningless


Not really meaningless especially when I'm doing a full throttle break in. I see you got Billy gobbing all over his motors checkin' temps. I can just imagine when I'm breaking in... heat gun, gob heat gun, gob That is some funny shit..... :D

Maximo 04-28-2010 05:20 PM


Originally Posted by CKmaxx (Post 7333886)
Not really meaningless especially when I'm doing a full throttle break in. I see you got Billy gobbing all over his motors checkin' temps. I can just imagine when I'm breaking in... heat gun, gob heat gun, gob That is some funny shit..... :D

Breakin is an exception of course !...

but you better be sure to calibrate the gun to the cooling head...these guns will read differently from engine to engine, so be sure the numbers you are using are actually accurate ! ..... However tuning to temps is the wrong way to tune... first being that there is no set temp for these engines to run, and secondly unless you calibrate the gun to the head you have no idea how accurate the gun is really reading..... Every time I go running the guys having the tuning issues are the guys using their temp guns......

NitroFreakManHo 04-28-2010 11:22 PM


Originally Posted by CKmaxx (Post 7333886)
Not really meaningless especially when I'm doing a full throttle break in. I see you got Billy gobbing all over his motors checkin' temps. I can just imagine when I'm breaking in... heat gun, gob heat gun, gob That is some funny shit..... :D

lol Billy, you just keep on toting that temp gun around and keep tweaking and fiddling with those needles chasing that perfect tune, while I'm out on the track driving my gear ( just like last year :lol: ). Break-in is the only time I need a temp gun because I have the know-how to tune without one:lol::lol: OUCH!

NitroFreakManHo 04-28-2010 11:23 PM


Originally Posted by Maximo (Post 7333914)
Breakin is an exception of course !...

but you better be sure to calibrate the gun to the cooling head...these guns will read differently from engine to engine, so be sure the numbers you are using are actually accurate ! ..... However tuning to temps is the wrong way to tune... first being that there is no set temp for these engines to run, and secondly unless you calibrate the gun to the head you have no idea how accurate the gun is really reading..... Every time I go running the guys having the tuning issues are the guys using their temp guns......

+10

lsbully 04-29-2010 07:11 AM

I really appreciate your help gents!
Got home yesterday, excited about removing a head shim and running the car, that soon turned into what the F, when my allen wrench broke and was stuck in the bolt, after standing there in disbelief, and trying to remove it, I gave up and ran the car.
It ran very well, I put tank after tank after tank thru it, for bout 30 minutes, and it only died twice, that happened just like it did before, but this time no gurggling sounds, just died.
So late lastnight I thought about what I should do to remove the bolt with the allen wrench in it, got a carbide ball file, chucked it up, ground down the bolt and allen wrench and drilled the fastener out, with no damage to the head or other parts what so ever...THANK YOU LUCK!
I removed one shim and will run it again today!

kgombe 04-29-2010 09:17 AM

kool... the idle on these things is a little iffy.. so be patient while setting it and pay attention to the sound and how it dies to make your adjustments

NitroFreakManHo 04-29-2010 09:41 AM


Originally Posted by lsbully (Post 7336583)
I really appreciate your help gents!
Got home yesterday, excited about removing a head shim and running the car, that soon turned into what the F, when my allen wrench broke and was stuck in the bolt, after standing there in disbelief, and trying to remove it, I gave up and ran the car.
It ran very well, I put tank after tank after tank thru it, for bout 30 minutes, and it only died twice, that happened just like it did before, but this time no gurggling sounds, just died.
So late lastnight I thought about what I should do to remove the bolt with the allen wrench in it, got a carbide ball file, chucked it up, ground down the bolt and allen wrench and drilled the fastener out, with no damage to the head or other parts what so ever...THANK YOU LUCK!
I removed one shim and will run it again today!

Nice work! I'm glad that you never had to cut the head off. I'm happy to hear that your engine is running better now. :D

lsbully 04-29-2010 09:45 AM

Any ideas as to why it would just die when i give it gas after it sits for about 30 seconds

-R2- 04-29-2010 09:47 AM

it's fine it's just loading up with so much fuel, while sitting if flamed out around 5 sec. then you would lean the low speed needle and adjust idle.

easyryder 04-29-2010 06:03 PM

Just lean bottom a little bit, its good that it dies after sitting that long, sounds about right, Two cycle engines will load up at idle, this is normal, if it idles all day it wil run like crap, too lean, dont mess with it too much. When the engine is completely warmed up and cleaned out it should idle fairly stable till 20-30 seconds, then hit the gas, if it dies right away= too rich, if its crisp and strong= too lean, welcome to Nitro tuning Hell:lol: You will get it:cool:

CKmaxx 04-29-2010 10:18 PM


Originally Posted by NitroFreakManHo (Post 7335514)
lol Billy, you just keep on toting that temp gun around and keep tweaking and fiddling with those needles chasing that perfect tune, while I'm out on the track driving my gear ( just like last year :lol: ). Break-in is the only time I need a temp gun because I have the know-how to tune without one:lol::lol: OUCH!


Listen to you! You are the fiddler. Besides Neal tunes your motors over the phone, does he not? Lmfao!! ;)

Ah Billy, gotta love ya.....

lsbully 04-30-2010 02:46 PM

HELP!!!!
After running and running the car it started acting haywire. When I got the motor I did the seal aaround backplate and carb.
Today I did the leak check under water and it is leaking air from the Drum Barrel (Not the groove that is cut in it for the idle screw) but the small groove, yet the Idle screw itself isnt leaking.
I took the idle screw out to check the oring, and discovered that the end of the idle screw is all marred up.
I know I need to get a new idle screw, but what causes it to leak air from the groove. Could this part of the issue I am having?

lsbully 04-30-2010 03:13 PM

Ok let me say, after I replaced oring on idle screw, and did another leak check, IT IS LEAKING FROM IDLE GROOVE.
Sorry I misinformed you earlier


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