Help ... fuel issue with Nitro engine?

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RicoBanderez

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Hi all,
It's been a while since I've posted (sorry) and its been a while since I've run my car and to that end I need some advice please all.

I can start my car but it won't continue running.

I prime it by pulling the trigger and blowing down the fuel line that connects to the exhaust, crank the pull cord and it starts really well but it just won't continue running.

I think it's fuel related and that once it's burnt off the fuel in the carb it just comes to a stop.

Is there a methodical way I can tinker and try to find the root cause?

I did take the heat sync off and pulled the glow plug out just to make sure everything is clean and runs smooth ... it all seems to be OK but I must confess to it not having done much for a while.

Thanks all
 

tudordewolf

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Is there a methodical way I can tinker and try to find the root cause?

I'd start by removing and cleaning the carb, removing the low speed and high speed needles, and flushing it out with rubbing alcohol or even better, brake cleaner.

It sounds like the problem is somewhere there.
 

Greywolf74

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If cleaning the carb doesn't work then Id test the fuel tank for air leaks as well as putting new fuel line on it. Make sure the exhaust pressure port isnt clogged up also and that the back pressure is pushing fuel through the system.
 

RicoBanderez

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Hey folks,
Thanks for the notes so far.
I've now taken the carb off and taken it apart to give it all a good clean.
I also took the exhaust off to give that a good clean and found that it was full of pink sludge so whether that's played any part of this I'm not sure....
There's no blockages to report so now that I've taken it all apart and cleaned it is there anything else I should check before putting it back together?
I'm not sure what I should be looking for.
Cheers
 

gandalfnz

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When you block the exhaust stinger with your finger and then crank the engine, does the fuel flow trough the fuel line towards the carb?
 

RicoBanderez

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When you block the exhaust stinger with your finger and then crank the engine, does the fuel flow trough the fuel line towards the carb?
Hi,
I'm not not sure at the moment. I've taken it all apart to clean so once I've got it back together I'll let you know!
Thank you đź‘Ť
 

gandalfnz

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This is usually the best indicator if there is an air leak or carb clog.
Once you block the exhaust, crank it, watch the fuel line and see if it flows to the engine/carb.
Good luck!

To check the tank and fuel lines, block one nipple on the tank with a finger, attached a silicone tube on the other and blow. Any air leaks you will notice right away.

Same with the carb, cover all the exit points with your fingers, attached a tube to the carb intake and blow, should be sealed and not letting any air out.

This is how I test my gear and it never failed me.
 

Greywolf74

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I usually check my tank, fuel line by blowing through it while its under water but you dont necessarily have to do it under water. pinhole type leaks will be easier to indentify that way though.
 

RicoBanderez

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Hey folks,
Just a thought on putting my carb back together... I've errored and didn't note the settings of the HSN, LSN or idle.
I can work out how many turns each has from full open to full closed but does anyone have any thoughts on where to position? Start in the middle for each?
Does anyone have a bit of a base setting for them?
 

Greywolf74

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The stock needle settings should be listed in the engines manual. What engine is it?

Idle needle should be set so that the carb has about a 1mm gap when fully closed.
 

RicoBanderez

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The stock needle settings should be listed in the engines manual. What engine is it?

Idle needle should be set so that the carb has about a 1mm gap when fully closed.
Hiya,
Sorry for the delay.
Engine is this :

https://www.modelsport.co.uk/product/hong-nor-force-21-35cc-engine-sg-crank-slide-carb-435129

It's a cheap starter engine from Modelsport. I wanted something cheap to learn with and then once I'm comfortable with correctly running in and setting up I thought I'd then upgrade.
 

Greywolf74

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Hiya,
Sorry for the delay.
Engine is this :

https://www.modelsport.co.uk/product/hong-nor-force-21-35cc-engine-sg-crank-slide-carb-435129

It's a cheap starter engine from Modelsport. I wanted something cheap to learn with and then once I'm comfortable with correctly running in and setting up I thought I'd then upgrade.
Heres the manual for that engine. It will have the stock settings in it.
https://asset.conrad.com/media10/ad...roke-model-car-engine-346-cm-19-bhp-14-kw.pdf
 
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gandalfnz

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Rapstard

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How old is your engine? Are you just breaking it in? With my latest nitro i followed all the steps when new but it wouldnt idle at factory settings. I set it to have slightly higher throttle until it warmed up and would idle. Otherwise, once it started it would soon stall at idle
 

burnskevin58

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Hi all,
It's been a while since I've posted (sorry) and its been a while since I've run my car and to that end I need some advice please all.

I can start my car but it won't continue running.

I prime it by pulling the trigger and blowing down the fuel line that connects to the exhaust, crank the pull cord and it starts really well but it just won't continue running.

I think it's fuel related and that once it's burnt off the fuel in the carb it just comes to a stop.

Is there a methodical way I can tinker and try to find the root cause?

I did take the heat sync off and pulled the glow plug out just to make sure everything is clean and runs smooth ... it all seems to be OK but I must confess to it not having done much for a while.

Thanks all
Usually if the engine is cleaned out after running the needle valves get gummed up.
I run 100 percent methanol to burn out the nitro, this takes about 30 secund or so. The best part is it cleans the needle valve as well as Burns out the oil that gums up on the piston top. Then I use Marvel Mystery Oil. For long term storage I go so far as to even pump some through the needle valves.
Or, it's not enough fuel richen it up. People tend to forget that our motors lean out when warm. This is why after cranking the engine over and over it finally starts but then die. It takes all that cranking to get enough fuel into the engine due to a too lean setting. Once running the lean setting can't supply enough fuel.
 

Greywolf74

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I run 100 percent methanol to burn out the nitro, this takes about 30 secund or so. The best part is it cleans the needle valve as well as Burns out the oil that gums up on the piston top. Then I use Marvel Mystery Oil. For long term storage I go so far as to even pump some through the needle valves.
This is complete overkill. Plus I wouldnt want to run my engines even for 30 seconds without any lubrication in there at all. You dont need to to do all of that to store a nitro engine. Even for long term storage just slather it up with ARO real good both in the glow plug hole and through the front of the carb. Make sure to spin the flywheel wheel a number of times so the oil is evenly distributed throughout the engine and it will be fine. I started up a nitro engine last year that had been in storage for 6-7 years and it had no issues other than it took a little work getting her to fire the first time. Worst case scenario you may have to take the carb off and soak it in nitro fuel for 20 minutes to work out anything that did get gummed up.

Not telling you not to do it but I wouldnt recommend anyone else to do all that. Just my :2cents:
 

burnskevin58

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This is complete overkill. Plus I wouldnt want to run my engines even for 30 seconds without any lubrication in there at all. You dont need to to do all of that to store a nitro engine. Even for long term storage just slather it up with ARO real good both in the glow plug hole and through the front of the carb. Make sure to spin the flywheel wheel a number of times so the oil is evenly distributed throughout the engine and it will be fine. I started up a nitro engine last year that had been in storage for 6-7 years and it had no issues other than it took a little work getting her to fire the first time. Worst case scenario you may have to take the carb off and soak it in nitro fuel for 20 minutes to work out anything that did get gummed up.

Not telling you not to do it but I wouldnt recommend anyone else to do all that. Just my :2cents:
Methanol is oil.... learned it from IMPBA HALL OF FAMERS back in the 80's and have been doing it ever since. Methanol is oil, and it only takes about half minute to burn out the nitro that attacks the alloy. Considering the engine is full of fuel, that fuels oil is also in the engine, haha. Once the nitro burns out that oil is still in the engine as it takes longer to burn out. Once the nitro and oil burns out the rpm will drop due to the rich needle setting.
I guess you never heard of FIA Fuel and glow engines. FIA Fuel is 100 percent methanol.
I have a few engines that are 35 plus years old and have been after run this way that are not pitted and run like new still today. Why because I know how to maintain my engines.
Pretty simple to do.
Just a extra tank with pure methanol and plug it into the carbs inlet tube or remote needle valve. Fire it up, and it will go to a idle a few seconds later it will start to raise the idle as the nitro burns and the mixture goes leaner.
Go back to school and learn what methanol is before you start talking about oil. The only reason we add oil is because methanol alone is not enough oil for nitro (nitro is not oil) so we add oil only to compensate for the nitro volume. But a glow engine will run just fine on methanol alone with the correct needle setting, methanol alone requires only a leaner setting and no added oil.
I bet you never had a engine last longer than 3 years tops without any work done to it. Probably because you don't know how to properly clean your engine afterwards.
Have a good day
 
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Greywolf74

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Methanol is oil.... learned it from IMPBA HALL OF FAMERS back in the 80's and have been doing it ever since. Methanol is oil, and it only takes about half minute to burn out the nitro that attacks the alloy. Considering the engine is full of fuel, that fuels oil is also in the engine, haha. Once the nitro burns out that oil is still in the engine as it takes longer to burn out. Once the nitro and oil burns out the rpm will drop due to the rich needle setting.
I guess you never heard of FIA Fuel and glow engines. FIA Fuel is 100 percent methanol. Go back to school brother.
Methanol is alcohol made mostly from natural gas afaik. Now if you can buy it in a form that contains an oil mixture like Nitro then I was unaware of that because I dont use it but you said 100% methanol which is just alcohol. Even if it is an alcohol/oil mix I'm not really sure I see a benefit to using it. If you run the engine dry then whatever residual nitro may be left in the engine is cancelled out by the proper use of ARO so you're doing extra work for nothing. Additionally, Id be leary of running anything beside nitro in a nitro engine. Its not going to combust at the same rate or have the same atmospheric compression properties and that could possibly cause an issue or extra wear on the engine. Even if theres no downsides to running it, its an extra step that isnt necessary. Again not telling you not to do it, I just wouldnt recommend anyone else do it unless they just want to make extra work for themselves.
 
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Greywolf74

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Go back to school and learn what methanol is before you start talking about oil. The only reason we add oil is because methanol alone is not enough oil for nitro (nitro is not oil) so we add oil only to compensate for the nitro volume. But a glow engine will run just fine on methanol alone with the correct needle setting, methanol alone requires only a leaner setting and no added oil.
Since you decided to go back and edit your post and bash me in it, please allow me retort.

Ok, so I went and did a little reading. Went back to school as it were. Methanol is CH3OH which means a Carbon molecule that has 3 hydrogen molecules attached to it is itself attached to an Oxygen molecule with its own Hydrogen molecule attached to it.
1024px-Methanol-2D.png

Now granted I didnt have many chemistry classes in college but I am aware that crude oil is made from hydrocarbons but gasoline is made from crude oil and it doesn't have enough lubrication properties to be able to run an engine without oil. Likewise Nitromethane ( CH3NO2 ) Also has the same CH3 hydrocarbons that Methanol has yet it has to be mixed with oil in order to provide proper lubrication so as far as I can tell methanol has no more lubrication properties than does nitromethane. If theres a chemist in the house please step in and correct me if I'm wrong.

BTW, Since school is in session maybe you should learn how debate works. Its a principle learning technique used the world over, especially in forums. I mean why even be in a forum unless you're trying to learn or teach people about a subject??? you're obviously an old head so you're not likely hear to learn and judging by your responses Id say you're not very keen on teaching anyone anything either if it takes any effort on your part.

I bet you never had a engine last longer than 3 years tops without any work done to it. Probably because you don't know how to properly clean your engine afterwards.
Have a good day
Not only are you condescending but you presume to know things about me that you have no way of knowing and for what? To try and belittle me for having a differing opinion? Even if I am wrong see "debate" above.

Just for your information yes its true that youve been in the hobby way longer than me but its not like I'm a noob either. I have at least 3 or 4 nitro engines that are over a decade old and still run perfectly well. I've still got my original Losi 357 engine from my first LST2 that I bought 15 years ago. Did you miss the part where I said I just said that I started a nitro engine that I had in storage for 6-7 years and it started and ran just fine? Maybe you should add reading for comprehension to your school curriculum.
Have a good day
 
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burnskevin58

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I would never run a 2 stroke on methanol alone for full tank running, (I have in the past with no problem at all as far as wear and tear goes).
But for "After running" and to burn out the nitro, yes, I do, and have been for better than 35 years. Methanol is an oil and there is no such thing as 100% methanol, that is a generic term used in the industry.
FIA fuel as we all know is 80/20 mix for competition. But actual competitors for testing run normally 98/2 mix, do you think that 2% caster does anything more than straight methanol? No, it doesn't. The 2% caster or synthetic is not used for lubrication, it's used to make compression that the high content methanol needs.
Methanol is between 94% and 97% pure with the remaining impurities being unburnable fuel "oil" "Fuel oil" so that's between 3% and 6% oil content, anyways.

Now considering caster and synthetic oils do not burn (Combust) at all, in the engine and simply pass through the engine taking heat out of the engine, through the exhaust port and into the pipe/muffler where it gathers waiting for the next revolution to get sucked back into the engine and re-used. Also considering when we shut down our engine there is fuel in the engine and lots of un-used oil in the case too. That when methanol only, is used to burn off the residual nitro, oil is in the engine (lots of oil actually) and not to mention unburnable fuel oil in the methanol anyways. Running the engine for half a secund with methanol only, will not harm it at all, as the engine is well lubed from residual oils and the unburnable fuel oil in the methanol.

I'm not going to argue with you anymore about it. I unlike you, I didn't go to GOOGLE school, I actually refined methanol along with other oils for a living. So, I think I know a thing or two about methanol, and oil in general.

I edited my post to be nice, as I am a smart a$$ considering I'm from Chicago. So, I figured edit it out where I jokingly mentioned go back to school. But yes, maybe you should go back to school and learn about oils, methanol being one oil.

I'm more concerned when I read that people use ATF fluid as after run oil, "yeah let's dump a bunch of sandpaper into our engine" considering ATF fluid has "grit" in it.

Have a good day.
 
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