Originally Posted by davidfast

Hello, I recently purchased a ORN80679 CRF Alpha .21 ABI Buggy Engine (ABC/5-ports ceramic).

Break in went great. Pinch is gone and the engine has great compression. There is about 1.5 gallons on the motor now.

Problem I'm having is with getting the engine to idle properly.

Plug Changed
Fuel line Changed
Pressure Line Changed
D8 Tank changed to RC8 tank old
RC8 Old Tank changed to a new RC8 Tank

.5mm It will idle for maybe 5 sec and die
increments there out to over 1mm it will idle longer 8 - 10 at most but still die.
(Of course I'm adjusting the LSN to try and get this to work right)


More info:
Motor is always warmed with a Comp Heat heater
I'm in Iowa where it's been in the 90's and 100's for the past month with high humidity



The motor is so new I would hope it's not a bearing or an O ring somewhere.

I did seal the motor up as suggested by a guide from a TLR driver on Youtube before doing the break in as well.

Any suggestions where to go next

Originally Posted by ScottyM

Honestly it sounds like you're either way too lean on LSN or way to rich.. I'd rest both needles and start over.. BTW the LSN will be in quite a ways, most of the time further then you expect..

Also, you might consider a cooler plug.. With that new of an engine, you might need it with that kind of heat and humidity.. I'm in oklahoma and I will be going from a 77t to 97t this weekend..

Originally Posted by davidfast

Hello, I recently purchased a ORN80679 CRF Alpha .21 ABI Buggy Engine (ABC/5-ports ceramic).

Break in went great. Pinch is gone and the engine has great compression. There is about 1.5 gallons on the motor now.

Problem I'm having is with getting the engine to idle properly.

Plug Changed
Fuel line Changed
Pressure Line Changed
D8 Tank changed to RC8 tank old
RC8 Old Tank changed to a new RC8 Tank

.5mm It will idle for maybe 5 sec and die
increments there out to over 1mm it will idle longer 8 - 10 at most but still die.
(Of course I'm adjusting the LSN to try and get this to work right)


More info:
Motor is always warmed with a Comp Heat heater
I'm in Iowa where it's been in the 90's and 100's for the past month with high humidity



The motor is so new I would hope it's not a bearing or an O ring somewhere.

I did seal the motor up as suggested by a guide from a TLR driver on Youtube before doing the break in as well.

Any suggestions where to go next

Originally Posted by shanef

Just lean the bottom end in. If it won't even idle properly on the starterbox, then there's no way it'll perform on the track.

Set your idle gap, fire it up and get it warm, then use the LSN to get it to idle properly. If it keep's flaming, or is spitting out raw fuel, then lean on the needles! It's also a good idea to seal the engine

Originally Posted by basher26

I have the same .21 and a .24 and with both I have had a terrible time tuning the idle to 0.5mm. I did most of what you did new fuel and pressure lines, new glow plug, 97t. I used the RON(WERKS) method of breaking in and that went well but setting the idle gap 0.5mm and idling has been a challenge. The only way I got it to work is to set a fat idle gap of 1.4mm it was still spiting fuel but it idled and didn't stall. It runs but it will load with fuel which you have to feather the throttle to clear then get the power.

I am interested in hearing what you find out, I would like to run the idle at a smaller gap that 1.4mm to save some fuel and avoid the fuel loading every time you idle then having to clear it to get to the power.

Any suggestions would be helpful.

Originally Posted by Maximo

do yourself a favor and put a Novarossi or OS carb on the engine.....just make sure to use the base o-ring from the Orion carb....

Originally Posted by davidfast

So is this something I should try as well? I don't understand why the included carb shouldn't work. Should have just bought an OS or a Nova if buying a 100+ carb is the answer to fix these things.

Originally Posted by Maximo

do yourself a favor and put a Novarossi or OS carb on the engine.....just make sure to use the base o-ring from the Orion carb....

Originally Posted by davidfast

So is this something I should try as well? I don't understand why the included carb shouldn't work. Should have just bought an OS or a Nova if buying a 100+ carb is the answer to fix these things.

Originally Posted by rc racer 103

Have you checked your pipe ? sounds like the oil in the pipe is heating up and blocking the presure line so it doesnt presurize the tank anymore ,, check it out ,it does happen to these pipes offen,many folks chase a tune for days and it was the pipe all the time !something to look at maybe

Originally Posted by ScottyM

Maximo has some good points and makes me wonder if you don't have something stuck in one of your needles?

Originally Posted by basher26

I was thinking the same thing with my situation... what is the best approach to going through this. Is it take the carb off then remove the HSN blow some air through it? Use some solvent?

Edit....
There was something in the HSN !!! the .24 is working fine!!!!!!!!!!!!!!! YEAH! Now the .21 ??

THANK YOU!

Originally Posted by FallenAllDay

Hi guys i recently purchased an orion b321 factory team engine and wondering whats the best pipe to use for my track. I run on quite a tight track with alot of hair pins and not alot of big jumps, the surface is hard packed but has a loose top surface, mainly wanting good fuel mileage.
Thanks