Running too rich when hot - Losi 5T

Welcome to RCTalk

Come join other RC enthusiasts! You'll be able to discuss, share and private message with other members of our community.


RC Newbie
Hello. Hopefully someone can give me a few pointers. My Losi 5T (29cc Dynamite) runs fine to begin with, but then gets extremely rich after reaching operating temperature. I then lean it up and it runs well for 2-5 minutes before richening up again. This cycle continues until the screw is almost all the way in. It's a bit crazy. It is basically new, so it's acted this was from the start. I have just replaced the carb (Walbro 990), new fuel lines, tank grommet and carb gaskets - I will run it again within a day or two to see if this helps, although an air leak should have made it run too lean. Hmm


RC Newbie
I forgot to mention that I installed a new Bartalone pipe after the break-in. I run non-ethanol 94 octane (I'm in Germany) with Castor 927 premix at 28:1. Other than that It's stock.


Hardcore RCNT User
Kern county ,Calif.
I forgot to mention that I installed a new Bartalone pipe after the break-in. I run non-ethanol 94 octane (I'm in Germany) with Castor 927 premix at 28:1. Other than that It's stock.
I had never heard of that happening ,nor do I think that it is possible to just start changing like that ,once the carb, settings are set ,
it shouldnt change ,however ,it could be more pressure build up in the tank causing more fuel to be forced into the cylinder than

It sounds more like a tank pressure problem ,were the tank builds up too much pressure ,the tank needs to ventilate ,you may
need to replace the cap or add a secondary tank vent devise!....:cool:


RC Newbie
It is a weird problem, but it's definitely happening. I replaced the grommet and the fuel hoses, so maybe that will take care of it. I am still using the stock tank cap and ventilator (assuming that the little thing is a ventilator).

Thanks for the response!


Hoof Hearted
Staff member
Military Veteran
In my recliner
RC Driving Style
Bashing, Flying
Odd situation since it's a 2 cycle gasoline engine. Normally these are problems only associated with the nitro engines. Hang in there, we've got several large scale guys who might be able to figure this out for you.

Create an account or login to comment

You must be a member in order to leave a comment

Create account

Create an account on our community. It's easy!

Log in

Already have an account? Log in here.

Thread starter Similar threads Forum Replies Date
R Hyper 7 running too rich? Buggy and Truggy 32
O Think I'm running too hot Chassis & Drivetrain 11
V OS .15 running too hot? Chassis & Drivetrain 1
M Am i running too hot (please help) Traxxas Revo 11
I Is my T-maxx running too hot Traxxas T-Maxx 4
S Running a lipo 11.1V 5200mAh in a stock Maverick Strada sc Electric RC 2
NurturantQuasar running 3s on brushed crawlers? RC Rock Crawlers 3
Freezectrl I've been working on this Savage 4.6 for 3 weeks and I can't get it running, help! Engines 18
NurturantQuasar Is there a cheaper esc that works with the traxxas Velineon motor running 3s? Electric RC 1
R Running your rc car dry? Large Scale RC 5
corneileous What springs/shock oils you guys running for bashing on Revo 3.3? Monster Trucks 2
stevendavis Anyone Running the Kyosho FO-XX GP V2? Nitro RC 2
joostin420 Anyone running HW 4985 1650kv in redcat be6s/TM e6 iii bes? Electric RC 8
Matt43 Losi 22.2 running gear fit 22.3 chassis Electric RC 0
Oldford Throttle servo running backwards Electronics 6
Brandon1 Running the prime tires Monster Trucks 3
Peeeenuuutt To those running a mamba monster X with a sensorless motor Electronics 5
RicoBanderez Hump Battery Discharge Current / Servo Running & Stall Current Electronics 3
Lazy Bushman Anyone running the Savage XS Flux Electric RC 10
B Losi Rock Rey Running Video Electric RC 4
D3MON Getting back to running Losi LST(2)? Nitro RC 77
D3MON Getting back to running MGT 4.6 Associated Monster GT & Rival 254
I Revo 3.3 help, won't stay running after sealing it Nitro RC 7
NinoS Center Diff question - running as RWD Chassis & Drivetrain 10
Newbie123 Revo 3.3 running issues Engines 1
aabaray13 Anyone still running a stand alone failsafe??? Electronics 3
NitroSCX10 Engine wont stay running!?!? Engines 3
HueyC Chirping / chattering running Redcat XTR Engines 8
HueyC Issue running my HPI RS4 Evo3 Mustang Nitro RC 1/10 scale Nitro RC 61
fisureman New OS .18TM running hot- possible air leak Engines 24
Raging Revo A good running temperature/Tighten up the Slippery clutch Traxxas Revo 1
S Nitro car running weird when getting hot Nitro RC 49
Daryl1989 Savage lrp.32 keeps running away! Chassis & Drivetrain 19
craig911 mac star .28 running problems fixed but some questions Engines 19
Jase125 Running Rich? Nitro RC 20
WVNed Anybody running a Kyosho Fo-XX Nitro. Nitro RC 29
griff7373 Axial Yeti running with my girls RC Rock Crawlers 18
C Engine Running Nitro RC 11
Rolex Anyone running Windows 10? General Chaos 14
J os21tm good running temperature Traxxas Revo 4
M Engine not running right... Chassis & Drivetrain 4
N Revo will not stay RUNNING ! Traxxas Revo 2
R Running it in Traxxas T-Maxx 6
street silence engine running hot, need help with needles Chassis & Drivetrain 9
craig911 running batteries in parallel Electronics 7
Elwood34 Anyone running nitrous? Nitro RC 142
J Can't Keep Running long enough to tune... Flooding one way roto.. HPI Savage 7
forrest11gump Not running Nitro RC 7
Reddog Cold running Traxxas T-Maxx 0
H All most up and running again Electronics 0
Similar threads