engine running rich but extremely hot.

[jayb6550]

Hello! i’m having troubles keeping the temp down on my nitro engine. I know the basics of tuning and what to look for when it’s running too rich or lean. originally, the engine was running too lean with temps getting up too 200-260 degrees after only a couple minutes of idling, so tuned it to run rich. I thought it was doing great. it had just the right amount of blue smoke and minimal oil coming out the exhaust. i check the temps and they are even hotter being 210-265 degrees after a couple minutes of idling. so i richened it out even more to the point when lots of smoke coming out and being a little sluggish on throttle. it shocked me to find out it was running at 290 degrees!! I noticed it started getting hot being the engine was smoking and was hardly moving the car any on throttle. any thoughts?

 

[gandalfnz]

Nothing you can do about this. Different engines run at different temps, generally as long as you are under 300 you are okay.
As long as you are sure there is no MAJOR ( I say major, as minor leaks can be somewhat normal) air leaks, and engine cooling is not obstructed.
Tune to sound and smoke, forget about monitoring the temps, if the engine sounds good, leave it and enjoy the hobby!

Engine will tell you when its lean, sound of the engine is the key. But, you said already you know how to tune!

What car is this btw?

 

[jayb6550]

Nothing you can do about this. Different engines run at different temps, generally as long as you are under 300 you are okay.
As long as you are sure there is no MAJOR ( I say major, as minor leaks can be somewhat normal) air leaks, and engine cooling is not obstructed.
Tune to sound and smoke, forget about monitoring the temps, if the engine sounds good, leave it and enjoy the hobby!

Engine will tell you when its lean, sound of the engine is the key. But, you said already you know how to tune!

What car is this btw?

Hello! i’m having troubles keeping the temp down on my nitro engine. I know the basics of tuning and what to look for when it’s running too rich or lean. originally, the engine was running too lean with temps getting up too 200-260 degrees after only a couple minutes of idling, so tuned it to run rich. I thought it was doing great. it had just the right amount of blue smoke and minimal oil coming out the exhaust. i check the temps and they are even hotter being 210-265 degrees after a couple minutes of idling. so i richened it out even more to the point when lots of smoke coming out and being a little sluggish on throttle. it shocked me to find out it was running at 290 degrees!! I noticed it started getting hot being the engine was smoking and was hardly moving the car any on throttle. any thoughts?

Nothing you can do about this. Different engines run at different temps, generally as long as you are under 300 you are okay.
As long as you are sure there is no MAJOR ( I say major, as minor leaks can be somewhat normal) air leaks, and engine cooling is not obstructed.
Tune to sound and smoke, forget about monitoring the temps, if the engine sounds good, leave it and enjoy the hobby!

Engine will tell you when its lean, sound of the engine is the key. But, you said already you know how to tune!

What car is this btw?

the car is a team losi xxxnt. it’s an old one haha! normally i don’t worry too much about temps when it’s running fine but it used to run pretty cold so the engine running at almost 300 degrees and smoking kinda concerned me. 300 degrees is also very hot for a 20 year old .15 motor. i’m pretty sure the temperature outside played a role in the temp as the other day it was colder outside and the engine ran at around 250.

 

[gandalfnz]

If the head is smoking, then its no good.
Check the fuel delivery system, that its all air tight.

 

[jayb6550]

If the head is smoking, then its no good.
Check the fuel delivery system, that its all air tight.

I just did as you said to see if it’s all air tight. no exhaust leaks, no leaks in the fuel line going from the exhaust to the fuel tank, no fuel tank leak, and no engine or carb leaks. but the fuel lines are worn so i’ll probably replace those. they want to come off easily. then if that doesn’t do anything. i’ll think about replacing the cooling head. I actually just finished cleaning the cooling head and the entire engine itself. the cooling head flaps were extremely dirty and the crankcase was too. also cleaned the air filter and put some oil in it. checked the compression and it’s amazing for how old it is. i’ll try running it again tomorrow and see how it does and if it doesn’t improve i’ll think about replacing the cooling head. thanks.

 

[gandalfnz]

If its all air tight and it ran at lower temps before, there can only be two things....weather or your tune.

 

[jayb6550]

If its all air tight and it ran at lower temps before, there can only be two things....weather or your tune.

It might just be too hot out for me to run it, it was nearing 95 degrees outside! Humidity was also pretty bad so you might be right about the weather. thank you for your help I really appreciate it!

 

[johnnydmd]

What fuel are you using?

 

[jayb6550]

What fuel are you using?

20% nitro 16% oil morgan fuel.

 

[tudordewolf]

20% nitro 16% oil morgan fuel.

Ah, Backyard Basher. Good for break-in but otherwise too oily for high performance tunes, and runs hot I think because it forces you to tune it leaner than you'd like in order to counteract how "gooey" it is. Everyone's experience will vary.

I wound up mixing mine 50/50 with their 20% nitro onroad blend (8% oil) to make a 12% oil blend, and I got nice cool tunes out of that, also easier to start.

 

[johnnydmd]

20% nitro 16% oil morgan fuel.

That's likely as least one of your problems.

Switch to a 25/10-12 blend, your engine will be much, much happier.

 

[jayb6550]

That's likely as least one of your problems.

Switch to a 25/10-12 blend, your engine will be much, much happier.

Yea I never really liked the fuel i’ve been getting, but it’s one of the only nitro fuels my local hobby shop stocks. it did used to run colder with the same stuff. but i’ll still order some I guess, do you have a preference on the brand?

 

[jayb6550]

Ah, Backyard Basher. Good for break-in but otherwise too oily for high performance tunes, and runs hot I think because it forces you to tune it leaner than you'd like in order to counteract how "gooey" it is. Everyone's experience will vary.

I wound up mixing mine 50/50 with their 20% nitro onroad blend (8% oil) to make a 12% oil blend, and I got nice cool tunes out of that, also easier to start.

my hobby store used to stock 20% nitro 12 percent oil. i’ve ran that before and it was just right. i’m now coming to the conclusion it’s the fuel.

 

[Madness RC]

Hello! i’m having troubles keeping the temp down on my nitro engine. I know the basics of tuning and what to look for when it’s running too rich or lean. originally, the engine was running too lean with temps getting up too 200-260 degrees after only a couple minutes of idling, so tuned it to run rich. I thought it was doing great. it had just the right amount of blue smoke and minimal oil coming out the exhaust. i check the temps and they are even hotter being 210-265 degrees after a couple minutes of idling. so i richened it out even more to the point when lots of smoke coming out and being a little sluggish on throttle. it shocked me to find out it was running at 290 degrees!! I noticed it started getting hot being the engine was smoking and was hardly moving the car any on throttle. any thoughts?

I don't know if this is going to be related to your solution or your problem or not so excuse me if maybe I come a little off the picture. I had something one time that would take runs halfway full the engine would run kind of hot around the 250s or 60s. And then what will happen is the item begins to go high. And one of the things I've learned over the years is adding a loop on the fuel to me it makes it consistent and keeps the pressure in a way that it provides adequate fuel so your two doesn't change while the car is running or the level of the fuel gets low. Maybe this is an amateur response but at least I've tried to put my two cents in

 

[jayb6550]

I don't know if this is going to be related to your solution or your problem or not so excuse me if maybe I come a little off the picture. I had something one time that would take runs halfway full the engine would run kind of hot around the 250s or 60s. And then what will happen is the item begins to go high. And one of the things I've learned over the years is adding a loop on the fuel to me it makes it consistent and keeps the pressure in a way that it provides adequate fuel so your two doesn't change while the car is running or the level of the fuel gets low. Maybe this is an amateur response but at least I've tried to put my two cents in

I’ll try it out, i’ll let you know if it changes any.

 

[STONER RC]

20% nitro 16% oil morgan fuel.

The fuel is your problem. 20% nitro should have no more the 12% oil. Ideally basher look for nitro with 10-12% oil. Racer look for below 10% oil, and more like 8-9%. The fuel plays a big part of the tunning. With the higher oil. Your engine is already thinking its running rich. Because of the high oil. The higher oil % is only for break-ins amd that's it. That's why everyone has a problem tunning trx 2.5 -3.3 nitro engines. Traxxas top fuel is garbage and has a super high oil % over 16 I believe. With better fuel you'll get better tunes on the engine. Plus the air temp, altitudes, and Humidity all come into a factor while tuning a nitro engine. Any other questions don't hesitate to ask man. Happy bashing...

 

[jayb6550]

The fuel is your problem. 20% nitro should have no more the 12% oil. Ideally basher look for nitro with 10-12% oil. Racer look for below 10% oil, and more like 8-9%. The fuel plays a big part of the tunning. With the higher oil. Your engine is already thinking it’s running rich. Because of the high oil. The higher oil % is only for break-ins amd that's it. That's why everyone has a problem tunning trx 2.5 -3.3 nitro engines. Traxxas top fuel is garbage and has a super high oil % over 16 I believe. With better fuel you'll get better tunes on the engine. Plus the air temp, altitudes, and Humidity all come into a factor while tuning a nitro engine. Any other questions don't hesitate to ask man. Happy Bashing.

Thanks for the help!!! I’ve sorted out this tuning issue pretty well and once I get some good fuel, i’ll let you know how it runs. I have it tuned the best I can with this high oil content. It’s running hot and rich still but at least it’s not overheating anymore. Probably got to start all over again due to how lean on the bottom end I have it to counteract with how rich it wants to run. Not sure if it runs hot because the humidity or the oil percentage but hopefully that goes away when I switch over. Once again thanks for the help!

 

[STONER RC]

Thanks for the help!!! I’ve sorted out this tuning issue pretty well and once I get some good fuel, i’ll let you know how it runs. I have it tuned the best I can with this high oil content. It’s running hot and rich still but at least it’s not overheating anymore. Probably got to start all over again due to how lean on the bottom end I have it to counteract with how rich it wants to run. Not sure if it runs hot because the humidity or the oil percentage but hopefully that goes away when I switch over. Once again thanks for the help!

No problem anytime bud. I forgot to ask what type of glow plug are you using. That could also be adding to the high temps. Running the wrong plug for what fuel your running will give you high temps.

Theres alot that comes into play when running nitro engines. The air temperature, humidity, and elevation your at above sea level. All come into a factor when it comes to nitro engines.

It takes a while for everyone to get how it all comes into play. It took me a while before I under stood how these little bastard nitro engines work and run. Here's a good read about glow plugs and they way there act and how to pick the rite plug for your situation.

https://www.rogershobbycenter.com/allaboutglowplugs

 

[jayb6550]

No problem anytime bud. I forgot to ask what type of glow plug are you using. That could also be adding to the high temps. Running the wrong plug for what fuel your running will give you high temps.

Theres alot that comes into play when running nitro engines. The air temperature, humidity, and elevation your at above sea level. All come into a factor when it comes to nitro engines.

It takes a while for everyone to get how it all comes into play. It took me a while before I under stood how these little bastard nitro engines work and run. Here's a good read about glow plugs and they way there act and how to pick the rite plug for your situation.

https://www.rogershobbycenter.com/allaboutglowplugs

i’m running a medium plug.