OK guys, need a little help here. i recently aquired an OFNA .21 on a maxx, and it runs HOT after only a few seconds of run time. the piston/sleeve looks good, but i think the carb may be messed up. i can't find one anywhere to replace it that doesn't cost 80 bucks. i really dont know which way to go with this one, please help!!!
-
Welcome to RCTalk! 🚀
Join the #1 RC community where hobbyists connect, share, and get expert advice on RC cars, trucks, boats, drones, and more!
- ✓ Friendly & passionate RC enthusiasts
- ✓ RC tips & troubleshooting
- ✓ Buy, sell & trade RC gear
- ✓ Share builds & upgrades
Running HOT HOT HOT
- Thread starter bigbronco
- Start date
This site may earn a commission from merchant affiliate
links, including eBay, Amazon, and others.
links, including eBay, Amazon, and others.
joshman1204
RCTalk Addict
- Messages
- 533
- Reaction score
- 3
- Points
- 0
- RC Driving Style
ok HOT doesn't help us very much ... these engines are supposed to run very hot somtimes upwards of 260. It would help more if we had an actual temp or atleast an idea of how the truck is performing.
Is it idling well? How is the acceleration, any bogging or cutting out? Also do you have a well defined smoke trail from the exhaust on accel.
Is it idling well? How is the acceleration, any bogging or cutting out? Also do you have a well defined smoke trail from the exhaust on accel.
- Thread starter
- #3
Temps are about 280 after 30 seconds run time. it refuses to idle for more than a minute and it is plenty rich, smoking at idle. if you open the throttle it has good response but dies out then cuts off after a few seconds.
ckeast420
Gone - bye bye.
richen you low speed needle by turning it counter clockwise atleast a 1/4 of a turn
joshman1204
RCTalk Addict
- Messages
- 533
- Reaction score
- 3
- Points
- 0
- RC Driving Style
I would set the carb back to factory settings and then see how it performs from there. If it is still getting hot after a few minutes of run time and richening the HSN or LSN doesn't seem to solve the problem then I would check for an air leak. Start with the easy stuff like fuel lines and fuel tanks and then progress to the engine and carb. It wouldnt hurt to pull the engine and seal it up with some good RTV while your doing all of this.
Greywolf74
I'M TO BLAME!
Lifetime Supporter!
Supporter
Excellence Award
Hospitality Award
Build Thread Contributor
RC Showcase: 8
If its shooting up to 280F in 30 seconds its gotta be way lean.
ckeast420
Gone - bye bye.
ckeast420
Gone - bye bye.
oh your fine,not everybody starts out knowing everything 
You could start with sealing the back plate and carb
theres a thread about it floatin around on here some were,il try to find it for you
---------- Post added at 11:50 AM ---------- Previous post was at 11:47 AM ----------
You could start with sealing the back plate and carb
theres a thread about it floatin around on here some were,il try to find it for you
---------- Post added at 11:50 AM ---------- Previous post was at 11:47 AM ----------
LOL yea yea, looking for o-ring kits now. I think the HSN o-ring is leaking. and this is the first time i have had to deal with this type of problem, be easy my friend.[/QUOTE
here is a link! theres a guide on post 6...also you may find the nitro tuning flow chart beneficial
https://www.rcnitrotalk.com/forum/showthread.php?t=60832
ckeast420
Gone - bye bye.
I'm not sure on that specific engine (never owned) but from common nitro experience i know there should always be at least one shim under your head and possibly more depending on what kind of fuel you plan to run
Have you had the head off to see how many is there?
Have you had the head off to see how many is there?
ckeast420
Gone - bye bye.
is it there now?
ckeast420
Gone - bye bye.
Grrr
sometimes i hate internet stuff!https://www.rcnitrotalk.com/forum/showthread.php?t=60832
link should be just above this text
and do you know what % of nitro your fuel is?
ckeast420
Gone - bye bye.
kool that link should help you alot with tuning
one shim should be fine for 20% id run a medium-hot plug and you should be good
one shim should be fine for 20% id run a medium-hot plug and you should be good
- Thread starter
- #20
aight, i am going to investigate this o-ring, having trouble finding the kits. i really think the carb is the prob. i also need to find the factory settings, but they arent easy to find eather.....lol thanks for your help
